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The Big Archive for System Design - 2023 Edition (PDF) is available now. And it's completely FREE. The PDF contains 𝐚𝐥𝐥 𝐦𝐲 𝐭𝐞𝐜𝐡𝐧𝐢𝐜𝐚𝐥 𝐩𝐨𝐬𝐭𝐬 published in 2023. What’s included in the PDF? 🔹 Netflix's Tech Stack 🔹 Top 5 common ways to improve API performance 🔹 Linux boot Process Explained 🔹 CAP, BASE, SOLID, KISS, What do these acronyms mean? 🔹 Explaining JSON Web Token (JWT) to a 10 year old Kid 🔹 Explaining 8 Popular Network Protocols in 1 Diagram 🔹 Top 5 Software Architectural Patterns 🔹 OAuth 2.0 Flows 🔹 What does API gateway do? 🔹 Linux file system explained 🔹 18 Key Design Patterns Every Developer Should Know 🔹 Best ways to test system functionality 🔹 Top 6 Load Balancing Algorithms 🔹 Top 12 Tips for API Security 🔹 𝐀𝐧𝐝 100+ 𝐦𝐨𝐫𝐞 – Like, follow and subscribe to our newsletter to receive the PDF download link: bit.ly/3KCnWXq

CI/CD Pipeline Explained in Simple Terms

Last day to get free access to all 7 ByteByteGo courses for 1 month. Link at the end. - System Design Interview Vol. 1 - System Design Interview Vol. 2 - Machine Learning System Design Interview - Coding Interview Patterns - Object-Oriented Design Interview - Generative AI System Design Interview - Mobile System Design Interview Whether you’re preparing for interviews or looking to deepen your architecture knowledge, this is a great opportunity. Check it out now at: bytebytego.com

Prompt injection tops the OWASP LLM Top 10 and there's no single fix. Instead, you stack defenses, each one catching what the others miss. Defenses come in two families: model-level and system-level. Model-level defenses teach the model to resist injection. - Spotlighting wraps untrusted text in control tags like … and tells the model to treat anything inside as data, not instructions. - Instruction Hierarchy fine-tunes the model to rank the developer's system prompt above the user's message, and both above third-party content. System-level defenses build a system around the LLM that bounds the damage. - Least-Privilege Tools: Give the agent the minimum tools it needs. - Human-in-the-Loop: Require explicit user approval before any sensitive action runs. - Planner / Executor Split: Two separate LLMs. The planner has tool access but never sees untrusted content. The executor reads untrusted content but has no tools. No single defense is enough. Production systems like Gmail stack them, and together they make indirect injection manageable. Over to you: what's the one defense you've seen work in production that isn't on this list?

All 7 ByteByteGo courses are FREE to access and end in 𝐥𝐞𝐬𝐬 𝐭𝐡𝐚𝐧 3 𝐝𝐚𝐲𝐬. Link at the end. - System Design Interview Vol. 1 - System Design Interview Vol. 2 - Machine Learning System Design Interview - Coding Interview Patterns - Object-Oriented Design Interview - Generative AI System Design Interview - Mobile System Design Interview Whether you’re preparing for interviews or looking to deepen your architecture knowledge, this is a great opportunity. Offer ends May 1. Check it out now at: bytebytego.com

SLA vs SLO vs SLI These three terms are related, but they mean different things. Knowing the difference helps you define what to measure, aim for, and promise your customers. Here's how they actually connect: - SLI (Service Level Indicator): This is the metric you're measuring. For a login service, it could be the ratio of successful login requests to total valid requests. It tells you how your service is performing right now. - SLO (Service Level Objective): You take that SLI and define a target around it. Something like "login availability should stay above 99.9% over a rolling 28-day window." When you're missing your SLO, it’s a signal to find out what's failing before customers notice. - SLA (Service Level Agreement): This is what you promise your customers in a contract. It's usually set lower than the SLO, say 99.5% monthly availability. If you breach it, you owe service credits. If your SLO and SLA are both set to 99.9%, then the moment your availability drops below 99.9%, you've already breached the agreement. The SLI tells you where you stand. The SLO tells you where you should be. The SLA tells your customers what they can expect.

We're building a new course, Build with Claude Code, and we'd love your input before we finalize it. If you're an engineer or engineering leader, we'd appreciate 3 minutes of your time. Your answers will directly shape what we cover. Thank you so much! Take the short survey: docs.google.com/forms/d/e/1FAI…

Polling vs Long Polling vs Webhooks vs SSE Four ways to get updates from a server. Each one makes a different tradeoff between simplicity, efficiency, and real-time delivery. Here's how they compare: - Polling: The client sends a request every few seconds asking "anything new?" The server responds immediately, whether or not there's new data. Most of those requests come back empty, wasting client and server resources. For use cases like an order status page where a small delay is acceptable, polling is the simplest option to implement. - Long Polling: The client sends a request, and the server keeps the HTTP connection open until new data is available or a timeout occurs. This means fewer empty responses compared to regular polling. Some chat applications used this pattern to deliver messages closer to real-time communication. - Server-Sent Events (SSE): The client opens a persistent HTTP connection, and the server streams events through it as they're generated. It is one-way, lightweight, and built on plain HTTP. Many AI responses that appear token by token are delivered through SSE, streaming each chunk over a single open connection. - Webhooks: Instead of the client asking for updates, the service sends an HTTP POST to a pre-registered callback URL whenever a specific event occurs. Stripe uses this for payment confirmations. GitHub uses it for push events. The client never polls or holds a connection open, it just waits for the server to call. Many systems don't rely on a single pattern. You may use polling for order status, SSE for streaming AI responses, and webhooks for payment confirmations.

A handful of research papers shaped the entire AI landscape we see today. The diagram below highlights 12 that we consider especially influential. What paper is missing from this list?

Figma Design to Code, Code to Design: Clearly Explained We spoke with the Figma team behind these releases to better understand the details and engineering challenges. This article covers how Figma’s design-to-code and code-to-design workflows actually work, starting with why the obvious approaches fail, how MCP solves them, and the engineering challenges that remain. Read the full newsletter here: blog.bytebytego.com/p/figma-design…

JWT Visualized

Essential AWS Services Every Engineer Should Know

Monolithic vs Microservices vs Serverless

Comparing 5 Major Coding Agents The diagram below compares the 5 leading agents across interface, model, context window, autonomy, and more. Here's what the landscape tells us.

CLI vs MCP AI agents need to talk to external tools, but should they use CLI or MCP? Here goes.

Our New Book on Behavioral Interviews Is Now Available on Amazon! The book is written by @ALEngineered and published by ByteByteGo. Steve is a former principal engineer at Amazon. His ability to break down complex interview dynamics into clear, actionable advice made this book possible. Still, it took us two years to get it ready. Here's what's inside: - 130+ interview questions, from the most common to the ones that catch candidates off guard - 72 example stories showing what strong answers look like, from entry level to principal - Clear guidance on what interviewers look for, including key signals and red flags - High-Signal Storytelling, a framework to build a story bank for any behavioral interview - A practical prep plan and interview-day techniques for follow-ups and unexpected questions Order your copy on Amazon: geni.us/Yiwg6 Note: the book will also be available in India in a week or two.

7 Key Load Balancer Use Cases

How Agentic RAG Works?

12 Claude Code Features Every Engineer Should Know

All 7 ByteByteGo ebooks, FREE for a limited time. Link at the end. - System Design Interview Vol. 1 - System Design Interview Vol. 2 - Machine Learning System Design Interview - Coding Interview Patterns - Object-Oriented Design Interview - Generative AI System Design Interview - Mobile System Design Interview Whether you’re preparing for interviews or looking to deepen your architecture knowledge, this is a great opportunity. Offer ends May 1. Please help spread the word. Check it out now at: bytebytego.com

How does REST API work?