ByteByteGo

Co-authored 4 books:
     - System Design Interview - Volume 1
     - System Design Interview - Volume 2
     - Coding Interview Patterns
     - Machine Learning System Design Interview

- Write weekly ByteByteGo newsletter on system design topics to 1,000,000+ subscribers.
- Grow the ByteByteGo YouTube channel to 1,000,000+ subscribers.

Author & Co-Founder

Twitter

Software Engineer

Apple

Zynga

Oracle

Software Developer

Modeln N

Associate Member of Technical Staff

Follow me for system design & book-writing tips.

Alex Xu is a software engineer and author. His book System Design Interview - An Insider’s Guide is one of Amazon's best-selling books in the “Distributed Systems & Computing” category.  As of December 2020, his book is being translated into 7 different languages (Traditional Chinese, Russian, Japanese, Spanish, Polish, Simplified Chinese, and Korean).

--------------
Newsletter: https://blog.bytebytego.com
Twitter: https://twitter.com/alexxubyte
YouTube: https://www.youtube.com/c/ByteByteGo

Alex Xu

Database Types You Should Know in 2025

There’s no such thing as a one-size-fits-all database anymore. Modern applications rely on multiple database types, from real-time analytics to vector search for AI. Knowing which type to use can make or break your system’s performance.

Relational: Traditional row-and-column databases, great for structured data and transactions.

Columnar: Optimized for analytics, storing data by columns for fast aggregations.

Key-Value: Stores data as simple key–value pairs, enabling fast lookups. 

In-memory: Stores data in RAM for ultra-low latency lookups, ideal for caching or session management.

Wide-Column: Handles massive amounts of semi-structured data across distributed nodes.

Time-series: Specialized for metrics, logs, and sensor data with time as a primary dimension.

Immutable Ledger: Ensures tamper-proof, cryptographically verifiable transaction logs.

Graph: Models complex relationships, perfect for social networks and fraud detection

Document: Flexible JSON-like storage, great for modern apps with evolving schemas.

Geospatial: Manages location-aware data such as maps, routes, and spatial queries.

Text-search: Full-text indexing and search with ranking, filters, and analytics.

Blob: Stores unstructured objects like images, videos, and files.

Vector: Powers AI/ML apps by enabling similarity search across embeddings.

Over to you: Which database type do you think will grow fastest in the next 5 years?

--
We just launched the all-in-one tech interview prep platform, covering coding, system design, OOD, and machine learning.

Launch sale: 50% off. Check it out: https://lnkd.in/euwKh6u8

#systemdesign #coding #interviewtips 
.

Author of 4 Bestselling Books | Co-Founder of ByteByteGo

No alternative text description for this image

Cloudflare is much more than just a CDN and DDoS protection service.

Let’s do a quick comparison of Cloudflare, AWS, and Azure.

Cloudflare has rapidly expanded beyond its traditional CDN roots, launching a suite of modern developer-first services like Workers, R2, D1, and so on. These offerings position it as a serious edge-native alternative to other cloud providers.

Here are the key cloud capabilities that Cloudflare supports:

1 - Edge Compute and Serverless
2 - Object and Blob Storage
3 - Relational Databases
4 - Containers
5 - Sandboxes
6 - Workflows
7 - AI Agents SDK
8 - Vector and AI search
9 - Data Connectivity
10 - AI Infrastructure
11 - Content Delivery Network
12 - DNS
13 - Load Balancing

Over to you: Have you used Cloudflare’s new offerings? What are your thoughts on them?

--
We just launched the all-in-one tech interview prep platform, covering coding, system design, OOD, and machine learning.

Launch sale: 50% off. Check it out: https://lnkd.in/euwKh6u8

#systemdesign #coding #interviewtips 
.

HTTP vs. HTTPS

When you open a website, the difference between HTTP and HTTPS decides whether your data travels safely or in plain sight. Here’s what actually happens under the hood:

HTTP:
- Sends data in plain text, anyone on the network can intercept it.
- The client and server perform a simple TCP handshake: SYN, SYN-ACK, ACK
- Fast but completely insecure. Passwords, tokens, and forms can all be read in transit.

HTTPS (SSL/TLS):
- Step 1: TCP Handshake: Standard connection setup.
- Step 2: Certificate Check: Client says hello. Server responds with hello and its SSL/TLS certificate. That certificate contains the server's public key and is signed by a trusted Certificate Authority. 

Your browser verifies this certificate is legitimate, not expired, and actually belongs to the domain you're trying to reach. This proves you're talking to the real server, not some attacker pretending to be it.

- Step 3: Key Exchange: Here's where asymmetric encryption happens. The server has a public key and a private key. Client generates a session key, encrypts it with the server's public key, and sends it over. Only the server can decrypt this with its private key.

Both sides now have the same session key that nobody else could have intercepted. This becomes the symmetric encryption key for the rest of the session.

- Step 4: Data Transmission: Now every request and response gets encrypted with that session key using symmetric encryption.

Over to you: What’s your go-to tool for debugging TLS issues, openssl, curl -v, or something else?

--
We just launched the all-in-one tech interview prep platform, covering coding, system design, OOD, and machine learning.

Launch sale: 50% off. Check it out: https://lnkd.in/euwKh6u8

#systemdesign #coding #interviewtips 
.

bytebytego

linkedin.com/company/the-rundown-ai

JSESSIONID

li_at

Talks about #systemdesign, #techinterview, and #bookpublishing

Karnav P.

Apache Kafka vs. RabbitMQ

Kafka and RabbitMQ both handle messages, but they solve fundamentally different problems. Understanding the difference matters when designing distributed systems.

Kafka is a distributed log. Producers append messages to partitions. Those messages stick around based on retention policy, not because someone consumed them. Consumers pull messages at their own pace using offsets. You can rewind, replay, reprocess everything. It is designed for high throughput event streaming where multiple consumers need the same data independently.

RabbitMQ is a message broker. Producers publish messages to exchanges. Those exchanges route to queues based on binding keys and patterns (direct, topic, fanout). Messages get pushed to consumers and then deleted once acknowledged. It is built for task distribution and traditional messaging workflows.

The common mistake is using Kafka like a queue or RabbitMQ like an event log. They're different tools built for different use cases.

Over to you:  If you had to explain when NOT to use Kafka, what would you say?

--
We just launched the all-in-one tech interview prep platform, covering coding, system design, OOD, and machine learning.

Launch sale: 50% off. Check it out: https://lnkd.in/euwKh6u8

#systemdesign #coding #interviewtips 
.

Explaining 9 types of API testing. 
 
🔹 Smoke Testing 
This is done after API development is complete. Simply validate if the APIs are working and nothing breaks. 
 
🔹 Functional Testing 
This creates a test plan based on the functional requirements and compares the results with the expected results. 
 
🔹 Integration Testing 
This test combines several API calls to perform end-to-end tests. The intra-service communications and data transmissions are tested. 
 
🔹 Regression Testing 
This test ensures that bug fixes or new features shouldn’t break the existing behaviors of APIs. 
 
🔹 Load Testing 
This tests applications’ performance by simulating different loads. Then we can calculate the capacity of the application. 
 
🔹 Stress Testing 
We deliberately create high loads to the APIs and test if the APIs are able to function normally. 
 
🔹 Security Testing 
This tests the APIs against all possible external threats. 
 
🔹 UI Testing 
This tests the UI interactions with the APIs to make sure the data can be displayed properly. 
 
🔹 Fuzz Testing 
This injects invalid or unexpected input data into the API and tries to crash the API. In this way, it identifies the API vulnerabilities. 

--
We just launched Become an AI Engineer | Learn by Doing: Cohort 2. If you missed Cohort 1, now’s your chance to join us for Cohort 2.

Check it out here: https://bit.ly/3LdaWuw

#AI #AIEngineer #MachineLearning 
.

The AI Agent Tech Stack

1. Foundation Models: Large-scale pre-trained language models that serve as the “brains” of AI agents, enabling capabilities like reasoning, text generation, coding, and question answering.
2. Data Storage: This layer handles vector databases and memory storage systems used by AI agents to store and retrieve context, embeddings, or documents.
3. Agent Development Frameworks: These frameworks help developers build, orchestrate, and manage multi-step AI agents and their workflows.
4. Observability: This category enables monitoring, debugging, and logging of AI agent behavior and performance in real-time.
5. Tool Execution: These platforms allow AI agents to interface with real-world tools (for example, APIs, browsers, external systems) to complete complex tasks.
6. Memory Management: These systems manage long-term and short-term memory for agents, helping them retain useful context and learn from past interactions.

Over to you: What else will you add to the list?

--
We just launched the all-in-one tech interview prep platform, covering coding, system design, OOD, and machine learning.

Launch sale: 50% off. Check it out: https://lnkd.in/euwKh6u8

#systemdesign #coding #interviewtips 
.

Big Data Pipeline Cheatsheet for AWS, Azure, and Google Cloud

Each platform offers a comprehensive suite of services that cover the entire lifecycle:

1 - Ingestion: Collecting data from various sources
2 - Data Lake: Storing raw data
3 - Computation: Processing and analyzing data
4 - Data Warehouse: Storing structured data
5 - Presentation: Visualizing and reporting insights

AWS uses services like Kinesis for data streaming, S3 for storage, EMR for processing, RedShift for warehousing, and QuickSight for visualization.

Azure’s pipeline includes Event Hubs for ingestion, Data Lake Store for storage, Databricks for processing, Cosmos DB for warehousing, and Power BI for presentation.

GCP offers PubSub for data streaming, Cloud Storage for data lakes, DataProc and DataFlow for processing, BigQuery for warehousing, and Data Studio for visualization.

Over to you: What else would you add to the pipeline?

--
LAST DAY to enroll in Become an AI Engineer Learn by Doing, Cohort 2. If you missed Cohort 1, now is your chance to join us in Cohort 2.

Check it out here: https://bit.ly/3LdaWuw

#AI #AIEngineer #MachineLearning 
.

Things Every Developer Should Know: Concurrency is 𝐍𝐎𝐓 parallelism.
.
.
In system design, it is important to understand the difference between concurrency and parallelism. 

As Rob Pyke(one of the creators of GoLang) stated:“ Concurrency is about 𝐝𝐞𝐚𝐥𝐢𝐧𝐠 𝐰𝐢𝐭𝐡 lots of things at once. Parallelism is about 𝐝𝐨𝐢𝐧𝐠 lots of things at once." This distinction emphasizes that concurrency is more about the 𝐝𝐞𝐬𝐢𝐠𝐧 of a program, while parallelism is about the 𝐞𝐱𝐞𝐜𝐮𝐭𝐢𝐨𝐧. 

Concurrency is about dealing with multiple things at once. It involves structuring a program to handle multiple tasks simultaneously, where the tasks can start, run, and complete in overlapping time periods, but not necessarily at the same instant. 

Concurrency is about the composition of independently executing processes and describes a program's ability to manage multiple tasks by making progress on them without necessarily completing one before it starts another.

Parallelism, on the other hand, refers to the simultaneous execution of multiple computations. It is the technique of running two or more tasks or computations at the same time, utilizing multiple processors or cores within a computer to perform several operations concurrently. Parallelism requires hardware with multiple processing units, and its primary goal is to increase the throughput and computational speed of a system.

In practical terms, concurrency enables a program to remain responsive to input, perform background tasks, and handle multiple operations in a seemingly simultaneous manner, even on a single-core processor. It's particularly useful in I/O-bound and high-latency operations where programs need to wait for external events, such as file, network, or user interactions.

Parallelism, with its ability to perform multiple operations at the same time, is crucial in CPU-bound tasks where computational speed and throughput are the bottlenecks. Applications that require heavy mathematical computations, data analysis, image processing, and real-time processing can significantly benefit from parallel execution.

--
We just launched the all-in-one tech interview prep platform, covering coding, system design, OOD, and machine learning.

Launch sale: 50% off. Check it out: https://lnkd.in/euwKh6u8

#systemdesign #coding #interviewtips 
.

5 REST API Authentication Methods

1. Basic Authentication: Clients include a Base64-encoded username and password in every request header, which is simple but insecure since credentials are transmitted in plaintext. Useful in quick prototypes or internal services over secure networks.
2. Session Authentication: After login, the server creates a session record and issues a cookie. Subsequent requests send that cookie so the server can validate user state. Used in traditional web-apps.
3. Token Authentication: Clients authenticate once to receive a signed token, then present the token on each request for stateless authentication. Used in single-page applications and modern APIs that require scalable, stateless authentication.
4. OAuth-Based Authentication: Clients obtain an access token via an authorization grant from an OAuth provider, then use that token to call resource servers on the user’s behalf. Used in cases of third-party integrations or apps that need delegated access to user data.
5. API Key Authentication: Clients present a predefined key (often in headers or query strings) with each request. The server verifies the key to authorize access. Used in service-to-service or machine-to-machine APIs where simple credential checks are sufficient.

Over to you: Which other API Authentication method have you seen?

--
We just launched the all-in-one tech interview prep platform, covering coding, system design, OOD, and machine learning.

Launch sale: 50% off. Check it out: https://lnkd.in/euwKh6u8

#systemdesign #coding #interviewtips 
.

Git Merge vs. Rebase vs. Squash Commit! 
. 
. 
What are the differences? 
 
When we 𝐦𝐞𝐫𝐠𝐞 𝐜𝐡𝐚𝐧𝐠𝐞𝐬 from one Git branch to another, we can use ‘git merge’ or ‘git rebase’. The diagram below shows how the two commands work. 
 
𝐆𝐢𝐭 𝐌𝐞𝐫𝐠𝐞 
This creates a new commit G’ in the main branch. G’ ties the histories of both main and feature branches. 
 
Git merge is 𝐧𝐨𝐧-𝐝𝐞𝐬𝐭𝐫𝐮𝐜𝐭𝐢𝐯𝐞. Neither the main nor the feature branch is changed. 
 
𝐆𝐢𝐭 𝐑𝐞𝐛𝐚𝐬𝐞 
Git rebase moves the feature branch histories to the head of the main branch. It creates new commits E’, F’, and G’ for each commit in the feature branch. 
 
The benefit of rebase is that it has 𝐥𝐢𝐧𝐞𝐚𝐫 𝐜𝐨𝐦𝐦𝐢𝐭 𝐡𝐢𝐬𝐭𝐨𝐫𝐲. 
 
Rebase can be dangerous if “the golden rule of git rebase” is not followed. 
 
𝐓𝐡𝐞 𝐆𝐨𝐥𝐝𝐞𝐧 𝐑𝐮𝐥𝐞 𝐨𝐟 𝐆𝐢𝐭 𝐑𝐞𝐛𝐚𝐬𝐞 
Never use it on public branches!

--
We just launched the all-in-one tech interview prep platform, covering coding, system design, OOD, and machine learning.

Launch sale: 50% off. Check it out: https://lnkd.in/euwKh6u8

#systemdesign #coding #interviewtips 
.

Top 20 System Design Concepts You Should Know

1. Load Balancing: Distributes traffic across multiple servers for reliability and availability.
2. Caching: Stores frequently accessed data in memory for faster access.
3. Database Sharding: Splits databases to handle large-scale data growth.
4. Replication: Copies data across replicas for availability and fault tolerance.
5. CAP Theorem: Trade-off between consistency, availability, and partition tolerance.
6. Consistent Hashing: Distributes load evenly in dynamic server environments.
7. Message Queues: Decouples services using asynchronous event-driven architecture.
8. Rate Limiting: Controls request frequency to prevent system overload.
9. API Gateway: Centralized entry point for routing API requests.
10. Microservices: Breaks systems into independent, loosely coupled services.
11. Service Discovery: Locates services dynamically in distributed systems.
12. CDN: Delivers content from edge servers for speed.
13. Database Indexing: Speeds up queries by indexing important fields.
14. Data Partitioning: Divides data across nodes for scalability and performance.
15. Eventual Consistency: Guarantees consistency over time in distributed databases
16. WebSockets: Enables bi-directional communication for live updates.
17. Scalability: Increases capacity by upgrading or adding machines.
18. Fault Tolerance: Ensures system availability during hardware/software failures.
19. Monitoring: Tracks metrics and logs to understand system health.
20. Authentication & Authorization: Controls user access and verifies identity securely.

Over to you: Which other System Design concept will you add to the list?

--
We just launched the all-in-one tech interview prep platform, covering coding, system design, OOD, and machine learning.

Launch sale: 50% off. Check it out: https://lnkd.in/euwKh6u8

#systemdesign #coding #interviewtips 
.

Virtualization vs. Containerization

Before containers simplified deployment, virtualization changed how we used hardware. Both isolate workloads, but they do it differently.

- Virtualization (Hardware-level isolation): Each virtual machine runs a complete operating system, Windows, Fedora, or Ubuntu, with its own kernel, drivers, and libraries. The hypervisor (VMware ESXi, Hyper-V, KVM) sits directly on hardware and emulates physical machines for each guest OS. 

This makes VMs heavy but isolated. Need Windows and Linux on the same box? VMs handle it easily. Startup time for a typical VM is in minutes because you're booting an entire operating system from scratch.

- Containerization (OS-level isolation): Containers share the host operating system's kernel. No separate OS per container. Just isolated processes with their own filesystem and dependencies.

The container engine (Docker, containerd, CRI-O, Podman) manages lifecycle, networking, and isolation, but it all runs on top of a single shared kernel. Lightweight and fast. Containers start in milliseconds because you're not booting an OS, just launching a process.

But here's the catch: all containers on a host must be compatible with that host's kernel. Can't run Windows containers on a Linux host (without nested virtualization tricks).

Over to you: What's your go-to setup: containers in VMs, bare metal containers, or something else?

--
We just launched the all-in-one tech interview prep platform, covering coding, system design, OOD, and machine learning.

Launch sale: 50% off. Check it out: https://lnkd.in/euwKh6u8

#systemdesign #coding #interviewtips 
.

What is a REST API?

REST (Representational State Transfer) is an architectural style for building APIs that use HTTP for communication. To be considered RESTful, an API should follow six key constraints:

- Client-Server: Separates the user interface from data storage and processing. This allows each side to evolve independently.

- Stateless: Each request contains all the information needed to process it; the server does not store session state between requests.

- Uniform Interface: Consistent resource naming and formats across the API, e.g., “/products”, “/users”.

- Cacheable: Responses explicitly indicate if they can be cached (e.g., Cache-Control) to improve performance.

- Layered System: Requests may pass through multiple layers (load balancers, auth services, etc.) before reaching the API server, but to the client it appears as a single endpoint. 

- Code on Demand (Optional): The server can send executable code (like JavaScript) to the client to extend its functionality.


Over to you: Which REST constraint do you think is most often overlooked in real-world APIs?

--
We just launched the all-in-one tech interview prep platform, covering coding, system design, OOD, and machine learning.

Launch sale: 50% off. Check it out: https://lnkd.in/euwKh6u8

#systemdesign #coding #interviewtips 
.

The HTTP Mindmap

HTTP has evolved from HTTP/1.1 to HTTP/2, and now HTTP/3, which uses the QUIC protocol over UDP for improved performance. Today, it’s the backbone of almost everything on the internet, from browsers and APIs to streaming, cloud, and AI systems.

At the foundation, we have underlying protocols. TCP/IP for IPv4 and IPv6 traffic. Unix domain sockets for local communication. HTTP/3 running over UDP instead of TCP. These handle the actual data transport before HTTP even comes into play.

Security wraps around everything. HTTPS isn't optional anymore. WebSockets power real-time connections. Web servers manage workloads. CDNs distribute content globally. DNS resolves everything to IPs. Proxies (forward, reverse, and API gateways) route, filter, and secure traffic in between.

Web services exchange data in different formats, REST with JSON, SOAP for enterprise systems, RPC for direct calls, and GraphQL for flexible queries. Crawlers and bots index the web, guided by robots.txt files that set the boundaries.

The network world connects everything. LANs, WANs, and protocols like FTP for file transfers, IMAP/POP3 for email, and BitTorrent for peer-to-peer communication. For observability, packet capture tools like Wireshark, tcpdump, and OpenTelemetry let developers peek under the hood to understand performance, latency, and behavior across the stack.

Over to you: HTTP has been evolving for 30+ years, what do you think the next big shift will be?

--
We just launched the all-in-one tech interview prep platform, covering coding, system design, OOD, and machine learning.

Launch sale: 50% off. Check it out: https://lnkd.in/euwKh6u8

#systemdesign #coding #interviewtips 
.

How DNS Works

You type a domain name and hit enter, but what actually happens before that webpage loads is more complex than most people realize. DNS is the phonebook of the internet, and every request you make triggers a chain of lookups across multiple servers. 

Step 1: Someone types bytebytego. com into their browser and presses enter. 

Step 2: Before doing anything, the browser looks for a cached IP address. Operating system cache gets checked too. 

Step 3: Cache miss triggers a DNS query. The browser sends a query to the configured DNS resolver, usually provided by your ISP or a service like Google DNS or Cloudflare.

Step 4: Resolver checks its own cache. 

Step 5-6: If the resolver doesn't have the answer cached, it asks the root servers, “Where can I find .com?” For bytebytego. com, the root server responds with the address of the .com TLD name server. 

Step 7-8: Resolver queries the .com TLD server. TLD server returns the authoritative server address. 

Step 9-10: This server has the actual A/AAAA record mapping the domain to an IP address. The resolver finally gets the answer: 172. 67. 21. 11 for bytebytego. com.

Step 11-12: The IP gets cached at the resolver level for future lookups, and returned to the browser.

Step 13-14: The browser stores this for its own future use, and uses the IP to make the actual HTTP request. 

Step 15: The web server returns the requested content.

All this happens in milliseconds, before your first page even starts loading.

Over to you: Which DNS tools or commands do you rely on most, dig, nslookup, or something else?

--
We just launched the all-in-one tech interview prep platform, covering coding, system design, OOD, and machine learning.

Launch sale: 50% off. Check it out: https://lnkd.in/euwKh6u8

#systemdesign #coding #interviewtips 
.

Linux file permission illustrated. 

𝐎𝐰𝐧𝐞𝐫𝐬𝐡𝐢𝐩
Every file or directory is assigned 3 types of owner:

🔹Owner: the owner is the user who created the file or directory.
🔹Group: a group can have multiple users. All users in the group have the same permissions to access the file or directory.
🔹Other: other means those users who are not owners or members of the group.

𝐏𝐞𝐫𝐦𝐢𝐬𝐬𝐢𝐨𝐧
There are only three types of permissions for a file or directory.

🔹Read (r): the read permission allows the user to read a file.
🔹Write (w): the write permission allows the user to change the content of the file.
🔹Execute (x): the execute permission allows a file to be executed. 

Over to you: chmod 777, good idea?

--
We just launched the all-in-one tech interview prep platform, covering coding, system design, OOD, and machine learning.

Launch sale: 50% off. Check it out: https://lnkd.in/euwKh6u8

#systemdesign #coding #interviewtips 
.

Types of Virtualization

Virtualization didn’t just make servers efficient, it changed how we build, scale, and deploy everything. Here’s a quick breakdown of the four major types of virtualization you’ll find in modern systems:

1. Traditional (Bare Metal): Applications run directly on the operating system. No virtualization layer, no isolation between processes. All applications share the same OS kernel, libraries, and resources.

2. Virtualized (VM-based): Each VM runs its own complete operating system. The hypervisor sits on physical hardware and emulates entire machines for each guest OS. Each VM thinks it has dedicated hardware even though it's sharing the same physical server.

3. Containerized: Containers share the host operating system's kernel but get isolated runtime environments. Each container has its own filesystem, but they're all using the same underlying OS. The container engine (Docker, containerd, Podman) manages lifecycle, networking, and isolation without needing separate operating systems for each application.

Lightweight and fast. Containers start in milliseconds because you're not booting an OS. Resource usage is dramatically lower than VMs.

4. Containers on VMs: This is what actually runs in production cloud environments. Containers inside VMs, getting benefits from both. Each VM runs its own guest OS with a container engine inside. The hypervisor provides hardware-level isolation between VMs. The container engine provides lightweight application isolation within VMs.

This is the architecture behind Kubernetes clusters on AWS, Azure, and GCP. Your pods are containers, but they're running inside VMs you never directly see or manage.

Over to you: In your experience, which setup strikes the best balance between performance and flexibility?

--
We just launched the all-in-one tech interview prep platform, covering coding, system design, OOD, and machine learning.

Launch sale: 50% off. Check it out: https://lnkd.in/euwKh6u8

#systemdesign #coding #interviewtips 
.

Vijaya Kalyani K.

Can a web server provide real-time updates? 
. 
. 
An HTTP server cannot automatically initiate a connection to a browser. As a result, the web browser is the initiator. What should we do next to get real-time updates from the HTTP server? 
 
Both the web browser and the HTTP server could be responsible for this task. 
 
🔹Web browsers do the heavy lifting: short polling or long polling. With short polling, the browser will retry until it gets the latest data. With long polling, the HTTP server doesn’t return results until new data has arrived. 
🔹HTTP server and web browser cooperate: WebSocket or SSE (server-sent event). In both cases, the HTTP server could directly send the latest data to the browser after the connection is established. The difference is that SSE is uni-directional, so the browser cannot send a new request to the server, while WebSocket is fully-duplex, so the browser can keep sending new requests. 
 
Over to you: of the four solutions (long polling, short polling, SSE, WebSocket), which ones are commonly used, and for what use cases? 

--
We just launched the all-in-one tech interview prep platform, covering coding, system design, OOD, and machine learning.

Launch sale: 50% off. Check it out: https://lnkd.in/euwKh6u8

#systemdesign #coding #interviewtips 
.

How do AirTags work?

AirTags work by leveraging a combination of Bluetooth technology and the vast network of Apple devices to help you locate your lost items. 
Here's a breakdown of how they function: 

1. Bluetooth Signal: Each AirTag emits a secure Bluetooth signal that can be detected by nearby Apple devices (iPhones, iPads, etc.) within the Find My network. 

2. Find My Network: When an AirTag comes within range of an Apple device in the Find My network, that device anonymously and securely relays the AirTag's location information to iCloud. 

3. Location Tracking: You can then use the Find My app on your own Apple device to see the approximate location of your AirTag on a map. 

Limitations: 
Please note that AirTags rely on Bluetooth technology and the presence of Apple devices within the Find My network. If your AirTag is in an area with few Apple devices, its location may not be updated as frequently or accurately. 

--
We just launched the all-in-one tech interview prep platform, covering coding, system design, OOD, and machine learning.

Launch sale: 50% off. Check it out: https://lnkd.in/euwKh6u8

#systemdesign #coding #interviewtips 
.

Amazon

Director, Software Development

Senior Software Development Manager

Software Development Manager - SCOT

Sr. Technical Program Manager - GIPA

Amazon Payment Services

As the leader of the global technology function at Amazon Payment Services, I am both passionate about and dedicated to re-imagining digital payments for customers and merchants throughout the Middle East and Africa region. 

My responsibilities encompass tech pre-sales and solutioning, merchant integration, software development (for new and existing products), infrastructure management, technical operations, information security, and data engineering. Additionally, I oversee the technology function responsible for delivering seamless payment products and experiences for Amazon shoppers throughout MEA stores (UAE, KSA, EGY, TR and ZA). 

Together, our aim is to provide simple, affordable, and trusted payment experiences for merchants and customers across the MEA region.

Head of Technology

Direct Energy

Promoted to build and lead 5-member team in designing, developing, and managing decision-support application and tools for front-office trading group, integrating with trading/supply, operations, risk management, pricing/structuring, settlements organizations.

IT Manager - Decision Support Tools, Supply

Extended inward-focused IT capabilities to external customers. Developed capabilities that underpin key business processes within the industry lifecycle including trading, scheduling, asset management and optimization, demand-side response, and settlements. 

* Challenged with building team, processes, and systems to support organic business growth into new market space with demand response management product (multi-million dollar project). 

* Leveraged technology to empower several key, new revenue streams for the business unit.

* Handpicked by senior leadership to course-correct and manage delinquent security appliances workstream of major datacenter migration that had put entire project at significant risk of missing deadlines. 

* Invited to join M&A (and other structured deal) due diligence teams after demonstrating thought leadership in both technology and operations to commercial stakeholders. 

* Updated business continuity program to eliminate operational risk from disruption to business-critical systems.

IT Manager - Digital Marketing, Upstream and Trading

Managed IS development and support function for variety of business-enabling systems across US power markets. Built and directed team of 6 IT professionals.

* Functions Supported include:

   a) ISO Settlements (NEPOOL, NYISO, PJM, CAISO, MISO and ERCOT) / nMarket Allocation  Manager and custom SSRS reports
   b) Scheduling and ISO Trading / nMarket Power
   c) Upstream Power / OSIsoft PI System and various other systems
   d) ERCOT Asset Optimization and 24 Hour Real-Time Trading Desk / nMarket Power
   e) ERCOT Asset Dispatching / OSI Monarch GMS

* Major Initiatives Lead:

- Texas Nodal Market Transition (Go-Live and Post Go-Live Support)
- Generation Management System (GMS) Implementation (Inception to Operations)

* Managed Business Continuity Planning and Disaster Recovery plans for Direct Energy Upstream & Trading

IS Manager - Power Asset Optimization, 24-Hour Real-Time Trading Desk, and Upstream Power

* Developed a 3 year architectural - enterprise message bus centered - vision  for our Upstream and Trading business unit

* Developed a Data Integrity business case for our Upstream and Trading business unit

* Developed an interface for gas pipeline data with Bentek Energy

* Managed a Market Data Service initiative to consolidate Market Data into a single repository

* Managed environments to support our Proprietary Trading applications

* Managed testing environments for the Texas Nodal Initiative and various other initiatives

* Supported Proprietary Trading applications

Senior Analyst - Architecture and Proprietary Trading IS

* Lead the design, implementation and testing of the Trade Capture migration from a Java based API to a FIX based system with the Intercontinental Exchange (ICE)

* Developed various solution components in Java and TIBCO

* Supported DealCapture and E-Confirm applications

* Developed Retail Credit Risk BI solution to support B2B business better evaluate/assess credit exposure

Senior Analyst - Wholesale/Retail Interface IS

* Provided technical leadership over design, implementation and testing of the SAP HR implementation project, to replace existing PeopleSoft implementation

* Actively participated in the business blueprinting of to-be HR processes, and translating the processes into system functional requirements

* Provided technical leadership over design, implementation and testing of the Canadian Benefits outsourcing project as well as coordinating the Payroll Outsourcing Project 

* Initiated SAP ECC 6.0 upgrade recommendation and laying project foundation

* Lead the testing and training for the Scanning Solution of the Procure-to-Pay project

Senior Analyst - Corporate IS

British Gas

* Led a project to develop an absence management system and managed its deliverables

* Collected the requirements, designed and implemented system using an agile customer centric development methodology

* Successfully sold the system to different areas of the business which is now being rolled out across British Gas Residential IS as well as British Gas Business IS

* Supported and administered the system in production for 100 users, with about 1,000 users being targeted for the short term

*Delivered project benefits estimated to save 0.5 FTE in each of the areas that it is rolled out to

Senior Analyst

* Collected the requirements, designed and implemented a deal capture system to automate energy trade entry from ICE and NGX into the company’s risk management system

* Supported the system in production, providing second level support

* Developed a front end application to the system to make it self-administrative

* Delivered project benefits estimated at: saving 2 FTE, reducing the error entry rate to 0.5% and the Value at risk by $2.5 Million

* Researched Natural Gas storage fundamentals in North America and investigated potential of its use within the Wholesale’s group portfolio

Senior Analyst - IS EMG

Integrated Voice Communications

* Managed the installation of new equipment and periodic updates (both software and hardware)

* Marketed and sold new VOIP (Voice over Internet Protocol) routes to various international destinations around the globe

* Programmed Cisco Routers and CPM (Computer Protocol Malaysia) voice gateways

* Maintained a set of Windows NT servers and Cisco gateways

* Managed 24/7 customer support (both technical and sales) by email/phone/fax

* Maintained excellent written and verbal communication skills as well as rigorous documentation

* Coordinated with team members in different countries to ensure quality voice service

Founder and Managing Partner

Tech Director at Amazon Payment Services | Follow for posts about Leadership Development and Career Growth | Leadership & Career Mentor | Author Of Leadership in 60 Seconds

I ​am a global technology executive with over 20 years of experience. I am currently Director of Software Engineering at Amazon, leading the Technology function for Payments across the Middle East and Africa. In this role, my aim is to make the payment experience of our merchants (Amazon Payment Services) and customers (Stores) the most simple, affordable, and trusted.

Over my career, I'm honored to have delivered award-winning transformational initiatives that have created competitive advantage, enabled business growth, and exceeded customer expectations.

Known as a forward-thinking problem-solver ― skilled in both business and technology strategy ― I adapt and plan for evolving market needs, delivering initiatives with speed and agility. I am also deeply passionate about building, developing, managing, and leading high-performance teams. A strong communicator and relationship builder, I partner effectively with cross-functional stakeholders and am a trusted advisor within the company.

Ever since I stepped into my first managerial role, more than a decade ago, I quickly realized the profound impact strong leadership has on individuals, teams, and organizations. From that moment, I made it my mission to empower others in their leadership journeys, guiding them to reach new heights in their careers.

In support of this mission, I have developed a community on LinkedIn of over 70K+ like-minded professionals with whom I actively support, engage, and share daily content on leadership, management, and career. I have been recognized as a LinkedIn Top Voice (Blue Badge) and ranked #1 LinkedIn Arab World Creator in Management and Leadership. 

Outside of work, I am passionate about everything automotive, especially F1 racing (Forza Ferrari!). I enjoy sports in general, both playing and watching. I also have a keen interest in collecting fragrances, working out with a focus on strength training, and all things food—from learning about it and exploring new cuisines to preparing dishes and hosting gatherings. However, my favorite pastime is spending quality time with my family. 

Languages: English 🇺🇸 Arabic 🇱🇧 French 🇫🇷

Omar Halabieh

Most career advice is about standing out.
This is about showing up.

Consistently. 
Predictably. 
Without drama.

Reliability is the most underrated career skill.

It's not glamorous. 
It won't trend on social media. 
And there's no 'Reliability 101' course.

But your career grows at the speed of people's confidence in you.

Not your talent. 
Not your ambition. 
Not your potential.

Your reliability.

It’s the quiet skill that opens doors long before titles, certifications, or even experience do.

5 practical ways to build reliability — starting today:

1/ Always Close the Loop

When someone asks for something, acknowledge it and follow through. 
Most careers get derailed not by mistakes, but by silence.

2/ Do What You Say — When You Say It

Consistency beats capability. 
If you commit to less but deliver every time, people will trust you with more.

3/ Communicate Early (Especially When Behind)

Falling behind isn’t the problem. 
Surprising people is.
Let others know early — it builds trust.

4/ Create a Personal Operating Rhythm

Reliability isn’t innate — it’s engineered. 
Weekly planning, structured 1:1s, documented decisions. 
You rise to the level of your systems.

5/ Make Your Work Visible

Share progress before you're asked. 
Visibility doesn’t just build trust — it reinforces your momentum.

Reliability won’t get you applause. 
But it will get you opportunities.
It’s not a soft skill — it’s a career advantage.

What’s helped 𝘺𝘰𝘶 stay reliable?

---
Follow me, tap the (🔔) Omar Halabieh for Leadership and Career posts

Tech Director @ Amazon | I help professionals lead with impact and fast-track their careers through the power of mentorship

You're mid-sentence in a meeting. 
Someone cuts you off. Again. 
You smile, stay quiet, and lose your voice.

If you accept interruptions, you train others to ignore you.  

I've been in thousands of meetings over my career. 
Led teams. 
Presented to executives. 
Eventually became Director of Software Engineering.  

One pattern I’ve seen? 
People who get heard set boundaries.

7 (proven) ways to stop people from interrupting you:  

1/ Ask to continue  

When someone jumps in: pause, make eye contact. “If it’s alright, I’d like to finish my thought first.” 

Clear. Polite. Assertive.  

2/ Acknowledge, then steer back  

Let them finish. 

Then: “Thanks—let me quickly finish what I was saying.” 

Respectful but firm.  

3/ Set expectations upfront  

Start strong: “Feel free to note questions—we’ll tackle them during Q&A.” 

You set the rules.  

4/ Keep it short  

The longer you talk, the more chances to be cut off. 

Be direct. Be organized. Be done.  

5/ Use the right tools  

In Zoom? Use the ‘raise hand’ feature to stay organized. 
 
Chat for sidebar questions.

6/ Let your body do the talking  

Eye contact. Small hand raise. Keep talking. 

They’ll get the message. 

Confident body language stops interruptions before they start.  

7/ Provide feedback privately  

Most interrupters don’t even realize. 

After the meeting: "During the meeting, I felt I was being cut off a few times. I'd appreciate the chance to finish my points next time." 

Direct. Respectful. Problem solved.  


These work. I’ve used every one.  
Your voice matters. So do your ideas. 
Don’t let interruptions steal that.  

👉 Which tactic will you try today?  

PS: Someone getting interrupted? Step in. “Let’s hear the rest of what Sarah was saying.” That’s leadership.

Assumptions feel fast.    
But they’re also where trust breaks — and where judgment slips
  
Most professionals don’t stagnate because they lack skill.  
They stagnate because they believed they already knew.
 
You’ve seen the pattern.  
You’ve done this before.  
You trust your gut...  
So you stop asking questions.
 
That’s when mistakes happen.  
And that’s when trust quietly erodes.
 
If you want to be right a lot — and earn trust — lead with a question.

A single question can prevent:  
• Delivering the wrong thing  
• Misunderstanding what someone actually meant  
• Missing a risk that was obvious to others  
• Overlooking a dependency that derails everything
 
Early in your career, you’re rewarded for answers.
Later in your career, you’re rewarded for clarity —  
and clarity comes from questions.
 
→ “𝘞𝘩𝘢𝘵 𝘮𝘪𝘨𝘩𝘵 𝘐 𝘣𝘦 𝘮𝘪𝘴𝘴𝘪𝘯𝘨?”  
→ “𝘞𝘢𝘭𝘬 𝘮𝘦 𝘵𝘩𝘳𝘰𝘶𝘨𝘩 𝘩𝘰𝘸 𝘺𝘰𝘶 𝘨𝘰𝘵 𝘵𝘩𝘦𝘳𝘦.”  
→ “𝘏𝘦𝘭𝘱 𝘮𝘦 𝘶𝘯𝘥𝘦𝘳𝘴𝘵𝘢𝘯𝘥 𝘸𝘩𝘢𝘵 𝘺𝘰𝘶’𝘳𝘦 𝘰𝘱𝘵𝘪𝘮𝘪𝘻𝘪𝘯𝘨 𝘧𝘰𝘳.”
 
Better questions → better inputs → better decisions → more trust.
 
A statement closes the conversation. 
 A question opens it.
 
If you want to be trusted, ask better questions.
If you want to be right a lot, ask more questions — 
especially when you think you already know.
 
𝗣𝗦: Curiosity isn’t slowness.  It’s strategy.

What's your go-to question to avoid making assumptions?

---
Follow me, tap the (🔔) Omar Halabieh for Leadership and Career posts

Your calendar’s full.  
That’s the problem.

The thing you’re missing isn’t another meeting, another project, or another ‘alignment call.’
 
It’s slack — not the tool, the white space.

I used to treat it as waste.  
Empty time made me anxious, so I filled it.  
I felt productive — but I stayed stuck.  

In a world obsessed with productivity, slack is a leadership and career superpower:
  
𝟭/ 𝗦𝗹𝗮𝗰𝗸 𝗶𝗻𝗰𝗿𝗲𝗮𝘀𝗲𝘀 𝘆𝗼𝘂𝗿 𝘀𝘁𝗿𝗮𝘁𝗲𝗴𝗶𝗰 𝗮𝗹𝘁𝗶𝘁𝘂𝗱𝗲
 
If every hour is packed, you have no mental space to zoom out, connect dots, or think long-term.  You rise when you create the space to 𝘵𝘩𝘪𝘯𝘬, not just to 𝘳𝘦𝘢𝘤𝘵.
 
𝟮/ 𝗦𝗹𝗮𝗰𝗸 𝗶𝘀 𝗵𝗼𝘄 𝘆𝗼𝘂 𝗽𝗿𝗲𝘃𝗲𝗻𝘁 𝗳𝗶𝗿𝗲𝘀 — 𝗻𝗼𝘁 𝗷𝘂𝘀𝘁 𝗳𝗶𝗴𝗵𝘁 𝘁𝗵𝗲𝗺
 
Most “urgent problems” aren’t surprises.  They’re early signals we were too busy to notice.  Slack gives you the margin to catch issues before they blow up.
 
𝟯/ 𝗦𝗹𝗮𝗰𝗸 𝗺𝗮𝗸𝗲𝘀 𝘆𝗼𝘂 𝗺𝗼𝗿𝗲 𝗮𝘃𝗮𝗶𝗹𝗮𝗯𝗹𝗲 — 𝗮𝗻𝗱 𝗮𝘃𝗮𝗶𝗹𝗮𝗯𝗶𝗹𝗶𝘁𝘆 𝗯𝘂𝗶𝗹𝗱𝘀 𝘁𝗿𝘂𝘀𝘁
 
If your team can never find you, they stop coming to you.  Slack lets you be present in the right moments:  The quick checkpoint.  The 5-minute unblock.  The conversation that prevents a misunderstanding.
 
𝟰/ 𝗦𝗹𝗮𝗰𝗸 𝘁𝘂𝗿𝗻𝘀 𝘆𝗼𝘂 𝗳𝗿𝗼𝗺 𝗼𝗽𝗲𝗿𝗮𝘁𝗼𝗿 → 𝗺𝘂𝗹𝘁𝗶𝗽𝗹𝗶𝗲𝗿
 
When you're maxed out, you execute.  When you have slack, you coach, delegate, and develop people.  That’s how you scale yourself — and your career.
 
𝟱/ 𝗦𝗹𝗮𝗰𝗸 𝗶𝗻𝗰𝗿𝗲𝗮𝘀𝗲𝘀 𝘆𝗼𝘂𝗿 𝗾𝘂𝗮𝗹𝗶𝘁𝘆 𝗼𝗳 𝗱𝗲𝗰𝗶𝘀𝗶𝗼𝗻𝘀
 
Rushed leaders make reactive decisions.  Calm leaders make clear decisions.  Slack is a buffer between stimulus and response — and clarity lives in that buffer.
 
𝟲/ 𝗦𝗹𝗮𝗰𝗸 𝗽𝗿𝗼𝘁𝗲𝗰𝘁𝘀 𝘆𝗼𝘂𝗿 𝗲𝗻𝗲𝗿𝗴𝘆 (𝗮𝗻𝗱 𝗲𝗻𝗲𝗿𝗴𝘆 𝗶𝘀 𝘆𝗼𝘂𝗿 𝘁𝗿𝘂𝗲 𝗰𝗼𝗺𝗽𝗲𝘁𝗶𝘁𝗶𝘃𝗲 𝗮𝗱𝘃𝗮𝗻𝘁𝗮𝗴𝗲)
 
Back-to-back intensity burns out even the strongest performers.  Slack helps you sustain output — consistently and predictably.
 
But slack is hard.  
It forces you to say no. 
Set boundaries.  
Let go of the illusion of busyness.  
And sit with space.
 
It's a skill - and like any skill, it takes practice.
 
So start small.
Try 30 minutes of unbooked time. 
No agenda. Just space.  
Then notice what changes — in your focus, your energy, your decisions.

Your future self — and your team — will thank you.

taplio

The Battle

Alex Xu

Omar Halabieh

Followers

Posts

Engagements

Likes

Performance ScoreAlex Xu's LinkedIn Performance

Performance ScoreOmar Halabieh's LinkedIn Performance

Ready to grow your LinkedIn presence?

taplio

The Battle

Alex Xu

Omar Halabieh

Followers

Posts

Engagements

Likes

Performance Score.css-goub6s{font-size:var(--chakra-fontSizes-md);font-weight:500;color:var(--chakra-colors-gray-600);display:block;margin-top:var(--chakra-space-1);}Alex Xu's LinkedIn Performance

Performance ScoreOmar Halabieh's LinkedIn Performance

Ready to grow your LinkedIn presence?

Performance ScoreAlex Xu's LinkedIn Performance