System Design Explained: APIs, Databases, Caching, CDNs, Load Balancing & Production Infra

Level up your system design skills! This course progresses from foundational concepts to production-ready systems, covering databases, scaling, and load balancing. Learn practical techniques for building and securing APIs, including RESTful and GraphQL. Course developed by @hayk.simonyan ❤️ Support for this channel comes from our friends at Scrimba – the coding platform that's reinvented interactive learning: https://scrimba.com/freecodecamp ⭐️ Contents ⭐️ - 0:00:00 Introduction - 0:03:05 Single Server Setup - 0:07:12 Databases: SQL, NoSQL, Graph - 0:13:32 Vertical vs Horizontal Scaling - 0:16:22 Load Balancing - 0:25:08 Health Checks - 0:28:00 Single Point of Failure (SPOF) - 0:31:01 API Design - 0:47:17 API Protocols - 0:59:10 Transport Layer: TCP, UDP - 1:04:22 RESTful APIs - 1:19:04 GraphQL - 1:24:52 Authentication - 1:45:51 Authorization - 1:57:02 Security 🎉 Thanks to our Champion and Sponsor supporters: 👾 @omerhattapoglu1158 👾 @goddardtan 👾 @akihayashi6629 👾 @kikilogsin 👾 @anthonycampbell2148 👾 @tobymiller7790 👾 @rajibdassharma497 👾 @CloudVirtualizationEnthusiast 👾 @adilsoncarlosvianacarlos 👾 @martinmacchia1564 👾 @ulisesmoralez4160 👾 @_Oscar_ 👾 @jedi-or-sith2728 👾 @justinhual1290 -- Learn to code for free and get a developer job: https://www.freecodecamp.org Read hundreds of articles on programming: https://freecodecamp.org/news

This 5-hour comprehensive course covers everything from foundational concepts to advanced distributed systems. Whether you are a beginner or preparing for high-stakes tech interviews, this session provides the architectural mindset needed to build scalable applications that handle millions of users. Course Modules: Foundations: System Design mindset, Functional vs. Non-Functional Requirements, and Scalability (Vertical vs. Horizontal). Networking & APIs: Deep dive into DNS, REST APIs, GraphQL, gRPC, and WebSockets. Data & Storage: SQL vs. NoSQL, Replication, Partitioning (Sharding), and Caching strategies. Distributed Systems: CAP Theorem, Fault Tolerance, and Observability. Advanced Topics: Message Queues, Load Balancing algorithms, and real-world Monitoring. Final Case Study: A full system design walkthrough of a video streaming application. Designed for: ✅ Developers leveling up their backend architecture skills. ✅ Engineers preparing for interviews at FAANG and top product companies. ✅ Students curious about how large-scale platforms like YouTube and Netflix work internally. 🔗 Full System Design Notes: https://docs.telusko.com/docs/system-design/getting-started Check out our courses: Agentic AI Engineering with Python : https://go.telusko.com/agentic-ai-python Coupon: TELUSKO10 (10% Discount) Master Java Spring Development : https://go.telusko.com/learn-master Coupon: TELUSKO10 (10% Discount) For More Queries WhatsApp or Call on : +919008963671 website : https://telusko.com/ Udemy Courses: Java Spring:- https://go.telusko.com/Udemyjavaspring Java:- https://go.telusko.com/udemyteluskojava Spring: https://go.telusko.com/udemyteluskospring Java For Programmers:- https://go.telusko.com/javaProgrammers Python : https://go.telusko.com/udemyteluskopython Git : https://go.telusko.com/udemyteluskogit Docker : https://go.telusko.com/udemyteluskodocker Instagram : https://www.instagram.com/navinreddyofficial/ Linkedin : https://in.linkedin.com/in/navinreddy20 WhatsApp : https://go.telusko.com/whatsapp Discord : https://discord.gg/D8hWe9BqfF 00:00:00 Introduction 00:01:32 Index 00:03:24 Hello System Design 00:05:33 Designing - Alien Bank 00:19:34 Components of System Design 00:35:22 Types of Applications 00:37:03 Data Intensive Application 00:43:03 Compute Intensive Application 00:48:18 Types of Requirement 00:48:31 Functional Requirement 00:50:13 Non-Functional Requirement 00:56:17 Domain Name Service (DNS) 01:00:45 DNS System Architecture 01:08:25 Application Programming Interface (API) 01:13:25 Types of APIs 01:21:04 RESTful Request 01:37:28 RESTful Response 01:47:25 Database 01:49:47 Relational Database - SQL 01:52:23 DB Constraints 02:00:20 DB Joins 02:08:34 Non-Relational Database - NoSQL 02:17:35 Types of NoSQL Databases 02:27:31 Cache 02:38:07 Cache Strategies 02:47:10 Cache Eviction Policies 02:53:14 Load Balancer 02:57:13 Load Balancing Algorithms 03:15:18 Load Balancer Health Checks 03:20:25 Distributed Databases 03:23:25 Replication 03:24:39 Replication Algorithms 03:44:26 Partition 03:46:48 Partition Strategies 03:57:20 CAP Theorem 04:03:40 Message Queue 04:17:29 Pub-Sub Model 04:27:32 Fault/Error 04:34:39 Monitoring and Observability 04:36:59 API Handling Monitoring 04:41:38 Machine Monitoring 04:42:50 System Design of Streaming Application 05:05:25 Thank You

Learn DevOps fast in this crash course covering Git & GitHub, CI/CD pipelines, Docker, Kubernetes, IaC, and API deployment. Everything you need to automate dev and deployment. ⭐ Join JS Mastery Pro: https://jsm.dev/dops25-jsm 💎 Become a Top 1% Next.js Developer: https://jsm.dev/dops25-nextjs Use your promo code JAVA to get the Warp Pro plan for only $1, available for a limited time thanks to my friends at Warp! Warp: https://jsm.dev/dops25-warp Arcjet: https://jsm.dev/dops25-arcjet Neon: https://jsm.dev/dops25-neon 📁 FREE Video Kit (Code, Figma, Assets, Etc.): https://jsm.dev/dops25-kit 📙 Git & GitHub Course: https://jsm.dev/dops25-git 📘 Docker Course: https://jsm.dev/dops25-docker 👉 Next.js Testing Pro Course Waitlist: https://jsm.dev/dops25-testpro 👉 Backend Pro Course Waitlist: https://jsm.dev/dops25-backpro 👉 Tailwind Pro Course Waitlist: https://jsm.dev/dops25-twpro 👉 React.js Pro Course Waitlist: https://jsm.dev/dops25-reactpro 👉 React Native Pro Course Waitlist: https://jsm.dev/dops25-rnpro Rate us on TrustPilot: https://jsm.dev/trustpilot https://discord.com/invite/n6EdbFJ https://twitter.com/jsmasterypro https://instagram.com/javascriptmastery https://linkedin.com/company/javascriptmastery Business Inquiries: contact@jsmastery.pro Time Stamps: 00:00:00 — Introduction 00:06:04 — Introduction to DevOps 00:09:45 — What is DevOps 00:20:41 — What You Need to Learn in DevOps 00:25:42 — Version Control (Git & GitHub) 00:50:33 — CI/CD Pipelines 00:55:06 — Build Your First Pipeline 01:03:21 — Docker 01:55:39 — Kubernetes 02:03:35 — Kubernetes Demo 02:26:34 — Infrastructure as Code (IaC) 02:29:37 — More on DevOps Build & Deploy an API 02:30:49 — Setup 02:41:44 — ESLint Prettier 02:46:09 — Database Setup 02:54:18 — Logger & Middleware 03:05:15 — Authentication I 03:35:56 — Warp Setup 03:47:53 — Security Middleware 04:03:11 — Dockerization 04:21:49 — User CRUD 04:38:50 — Testing 04:48:35 — Next Steps

In this course, you’ll master Next.js 16, the latest version of the official React framework, and learn how to build powerful, full-stack applications using its new caching and performance features. You’ll put your skills into practice by creating and deploying a Dev Event Platform, a modern app where users can browse, create, and manage events. PostHog: https://jsm.dev/devevent-posthog WebStorm: https://jsm.dev/devevent-webstorm Junie AI: https://jsm.dev/devevent-junie Warp: https://jsm.dev/devevent-warp CodeRabbit: https://jsm.dev/devevent-coderabbit CodeRabbit CLI: https://jsm.dev/devevent-coderabbitcli Cloudinary: https://jsm.dev/devevent-cloudinary The Complete Testing Course is LIVE. 🔥 Bundle up now before the deal expires and get 33% Off‼ 👉 https://jsm.dev/devevent-testing 📗 GSAP Pro Course (includes GTAVI Website): https://jsm.dev/devevent-gsap 📕 Three.js 3D Pro Course: https://jsm.dev/devevent-threejs 📙 JavaScript Pro Course: https://jsm.dev/devevent-cpjsm 🚀 Launch Your SaaS Pro Course: https://jsm.dev/devevent-saas ‼ If the links aren’t working for you, please try using a VPN (e.g., in Nigeria) 📁 FREE Video Kit (Code, Figma, Assets, Etc.): https://jsm.dev/devevent-kit 👉 Backend Pro Course Waitlist: https://jsm.dev/devevent-backpro 👉 AI Development Pro Course Waitlist: https://jsm.dev/devevent-aipro 👉 Tailwind Pro Course Waitlist: https://jsm.dev/devevent-twpro 👉 React.js Pro Course Waitlist: https://jsm.dev/devevent-reactpro 👉 React Native Pro Course Waitlist: https://jsm.dev/devevent-nativepro Rate us on TrustPilot: https://jsm.dev/trustpilot https://discord.com/invite/n6EdbFJ https://twitter.com/jsmasterypro https://instagram.com/javascriptmastery https://linkedin.com/company/javascriptmastery Business Inquiries: contact@jsmastery.pro Time Stamps: 00:00:00 — Introduction 00:04:09 — Crash Course Intro 00:08:30 — Installation 00:11:45 — Project Structure 00:14:19 — App Router 00:17:16 — React Client & Server Components 00:23:40 — Routing 00:42:42 — Data Fetching 00:48:53 — API Routes 00:52:45 — Caching 00:56:05 — Build Adapters API 00:57:24 — Metadata 01:01:23 — Theory to Practice — — — 01:02:48 — Project Setup 01:18:01 — Homepage 01:41:35 — PostHog Setup 01:50:21 — MongoDB Setup 01:52:57 — Warp Setup 01:56:46 — Database Models & Connection 02:09:36 — CodeRabbit 02:16:11 — API Routes 02:27:03 — Image Upload 02:37:51 — Fetch API Routes 02:54:47 — Event Details Page 03:14:34 — Server Actions 03:28:05 — Caching 03:39:46 — PostHog: Booking Action & Tracking 03:54:05 — Deployment 03:58:15 — Outro

An LLM is an incredibly powerful brain that knows everything about humanity and nothing about you or the software you run. This video walks through the four buzzwords that turn that raw brain into a system you can trust: agent harness, loop engineering, LLM Ops, and eval. No jargon, step by step, technical or not. You can build anything. You can learn anything. 💪 Timeline 0:00 Intro: the 4 AI agent buzzwords 0:42 What an AI agent run actually is 1:52 The memory system: procedural, semantic, episodic 3:37 What "harness" really means (the horse) 5:07 Storing and updating memory (databases, skills, summarizer agent) 8:28 Retrieval: RAG, SQL vs semantic search 10:00 Tool calling and why agents loop 10:52 Loop engineering and end-loop guardrails 13:21 A Claude Code hooks example 14:18 Eval and LLM Ops: why you need them 15:55 Tracing every run (Langfuse, LangSmith) 16:43 Evaluation: LLM as a judge 17:20 Diagnosing what broke 18:16 The gate: ship the fix or fix the bug 18:57 Zoom out: the full system 19:53 Wrap up Launch Full-Stack App Template: https://github.com/ShenSeanChen/launch-mvp-stripe-nextjs-supabase My AI Agent Startup AutoManus.io is an AI sales lead manager for made-to-order product sales. We embed directly where conversations happen (WhatsApp, email, web chat) to capture inbound, automate follow‑ups, and kill CRM busywork; live with 4 pilots and 2 contracts in motion, pre‑seed backed by Character VC. Focused on US/UK/Germany, raising to expand engineering and scale deployments. ☕️ Buy me a coffee: https://buy.stripe.com/5kA176bA895ggog4gh - X: https://x.com/ShenSeanChen - Sean's Discord: https://discord.gg/tvECErKcFr - AutoManus Discord: https://discord.gg/5HhcNjCR - LinkedIn: https://linkedin.com/in/shen-sean-chen - Github Link: https://github.com/ShenSeanChen - Instagram: https://www.instagram.com/sean_ai_stories Sub Count when launched: 13,050 Top Github Repos - LaunchMVP NextJS,Supabase,Stripe (1015 stars): https://github.com/ShenSeanChen/launch-mvp-stripe-nextjs-supabase - ReactNextJSTips (114 stars): https://github.com/ShenSeanChen/yt-react-nextjs-tips - DeepResearchAgentBackend (70 stars): https://github.com/ShenSeanChen/yt-DeepResearch-Backend - SupabaseTipsKanban (64 stars): https://github.com/ShenSeanChen/yt-supabase-tips-kanban - RAGVectorDB (56 stars): https://github.com/ShenSeanChen/yt-rag - KimiK2Claude (37 stars): https://github.com/ShenSeanChen/yt-kimi-k2-claude - DeepResearchAgentFrontend (33 stars): https://github.com/ShenSeanChen/yt-DeepResearch-Frontend - AgenticRAG (13 stars): https://github.com/ShenSeanChen/yt-agentic-rag You Can Build Anything Playlist (Full-Stack Dev Without CS Degrees) - Core7: 95% React/NextJS Use Cases https://www.youtube.com/watch?v=vZzFlAjz4rA&list=PLE9hy4A7ZTmpGq7GHf5tgGFWh2277AeDR&index=16 - Core6: 95% Supabase Use Cases https://www.youtube.com/watch?v=Pnoq2tIif3s&list=PLE9hy4A7ZTmpGq7GHf5tgGFWh2277AeDR&index=15 - Core5: StripeNextJSSupabase https://www.youtube.com/watch?v=ad1BxZufer8&list=PLE9hy4A7ZTmpGq7GHf5tgGFWh2277AeDR&index=8 - Core4: AuthSupabaseGoogle https://www.youtube.com/watch?v=AZAU3ClAWWE&list=PLE9hy4A7ZTmpGq7GHf5tgGFWh2277AeDR&index=6 - Core3: FastapiGCPPro https://www.youtube.com/watch?v=u3sfqpzzo-U&list=PLE9hy4A7ZTmpGq7GHf5tgGFWh2277AeDR&index=5 - Core2: SupabaseHero https://www.youtube.com/watch?v=V0kmgkyPsVQ&list=PLE9hy4A7ZTmpGq7GHf5tgGFWh2277AeDR&index=4 - Core1: LaunchAnApp https://www.youtube.com/watch?v=iQ2izvGG4tQ&list=PLE9hy4A7ZTmpGq7GHf5tgGFWh2277AeDR&index=3 - Launch WhereToMeet w/ GoogleMaps, Calendar, Supabase, Cursor: https://www.youtube.com/watch?v=5xMjX1QxGUY&list=PLE9hy4A7ZTmpGq7GHf5tgGFWh2277AeDR&index=2 - Launch EncourageMe w/ Cursor, Supabase, Vercel https://www.youtube.com/watch?v=hnvL4xa2DHA&list=PLE9hy4A7ZTmpGq7GHf5tgGFWh2277AeDR

📚 Get the Figma kit, app prompts, and UI Designer tool & all my AI resources on Skool: https://bit.ly/46Fo98a 📈 Become a Wildly Profitable AI Entrepreneur: https://bit.ly/47iFLGW 🤝 Ready to transform your business with AI? Let's talk: https://bit.ly/4fnpOS0 📋 Get our FREE 14-day playbook for finding high-impact AI opportunities in any business: https://bit.ly/14-day-playbook- In this full course, you’ll master the new skill of Software Composing—building full-stack, revenue-generating web apps using nothing but your ideas and the right prompts. You’ll go from understanding databases and APIs to deploying a real SaaS product with authentication, live data and a real database. No coding experience? No problem. This course was built to help you gain the confidence and competence to turn ideas into income using natural language prompts or 'vibe coding' and the world’s most powerful AI tools like Bolt.new the sponsor of this video. Get started building no-code apps with Bolt now: https://bolt.new/ Timestamps: 0:00 - What We're Covering 2:47 - Chapter 1: Foundations 4:31 - What is Software Composing? 10:46 - What is a Web App? 13:35 - Front End VS Back End 18:48 - Databases: Your Software’s Memory 23:43 - APIs 29:29 - Authentication & Authorization 34:33 - Chapter 2: Building 37:00 - The Software Composing Landscape 41:03 - Build 1: Front End: UI Design & Initial Prompting 56:30 - Build 2: Backend: Databases & API 1:12:21 - Build 3: User Authentication & Authorization 1:30:59 - Deploying your App 1:34:00 - Debugging: Fixing What Breaks 1:37:34 - Chapter 3: Monetizing