System design, design patterns and AI for engineers — written deep-dives and companion videos from the LearnwithManoj YouTube channel.https://learnwithmanoj.com/en-ushttps://learnwithmanoj.com/blog/composite-pattern-files-folders-trees/https://learnwithmanoj.com/blog/composite-pattern-files-folders-trees/Show notes for the Composite Pattern video — when to use it, real-world examples (file systems, the DOM, React trees), and a code-free mental model.Mon, 11 May 2026 00:00:00 GMTdesign-patternsstructural-patternsoopsoftware-engineeringhttps://learnwithmanoj.com/blog/bridge-pattern-explained-kill-the-class-explosion/https://learnwithmanoj.com/blog/bridge-pattern-explained-kill-the-class-explosion/Bridge Pattern - the fix for class hierarchies that explode into `RedCircle`, `BlueCircle`, `RedSquare`, `BlueSquare`.Sat, 09 May 2026 00:00:00 GMTdesign-patternsoopsoftware-engineeringstructural-patternshttps://learnwithmanoj.com/blog/adapter-pattern-explained-the-usb-adapter-of-code/https://learnwithmanoj.com/blog/adapter-pattern-explained-the-usb-adapter-of-code/Adapter Pattern - the software version of a USB-C to USB-A dongle. When two pieces of code need to talk to each other but their interfaces don't match, Adapter…Fri, 08 May 2026 00:00:00 GMTdesign-patternsoopsoftware-engineeringstructural-patternshttps://learnwithmanoj.com/blog/securing-ai-agents-from-doing-bad-things/https://learnwithmanoj.com/blog/securing-ai-agents-from-doing-bad-things/Show notes for AI Explained Part 31 — sandboxing, permission scoping, instruction hierarchy, and the metrics that tell you whether your agent is safe to ship.Fri, 08 May 2026 00:00:00 GMTaiai-agentssecurityllmai-explainedhttps://learnwithmanoj.com/blog/ai-explained-finally-understand-ai-errors-human-in-the-loop-hitl/https://learnwithmanoj.com/blog/ai-explained-finally-understand-ai-errors-human-in-the-loop-hitl/Feeling overwhelmed by the fear of AI making huge mistakes? In this video, we break it down into simple pieces.Wed, 06 May 2026 00:00:00 GMTaiai-explainedllmhttps://learnwithmanoj.com/blog/ai-explained-semantic-caching-state-management-for-ai-agents/https://learnwithmanoj.com/blog/ai-explained-semantic-caching-state-management-for-ai-agents/Feeling overwhelmed by high AI API costs and latency? In this video, we break it down into simple pieces.Tue, 05 May 2026 00:00:00 GMTaiai-explainedllmhttps://learnwithmanoj.com/blog/ai-explained-short-term-vs-long-term-ai-memory-demystified/https://learnwithmanoj.com/blog/ai-explained-short-term-vs-long-term-ai-memory-demystified/Feeling overwhelmed by the different layers of AI memory? In this video, we break it down into simple pieces.Mon, 04 May 2026 00:00:00 GMTaiai-explainedllmhttps://learnwithmanoj.com/blog/ai-explained-finally-understand-how-ai-agents-remember-you/https://learnwithmanoj.com/blog/ai-explained-finally-understand-how-ai-agents-remember-you/Feeling overwhelmed by memory and state tracking? In this video, we break it down into simple pieces.Sun, 03 May 2026 00:00:00 GMTaiai-explainedllmhttps://learnwithmanoj.com/blog/ai-explained-multi-agent-ai-systems-for-complete-beginners/https://learnwithmanoj.com/blog/ai-explained-multi-agent-ai-systems-for-complete-beginners/Feeling overwhelmed by the idea of communicating AIs? In this video, we break it down into simple pieces.Sat, 02 May 2026 00:00:00 GMTaiai-explainedllmhttps://learnwithmanoj.com/blog/ai-explained-how-ai-uses-tools-react-loop-tool-use-demystified/https://learnwithmanoj.com/blog/ai-explained-how-ai-uses-tools-react-loop-tool-use-demystified/Feeling overwhelmed by APIs and AI Tool Integration? In this video, we break it down into simple pieces.Fri, 01 May 2026 00:00:00 GMTaiai-explainedllmhttps://learnwithmanoj.com/blog/ai-explained-finally-understand-autonomous-ai-agents-agentic-rag/https://learnwithmanoj.com/blog/ai-explained-finally-understand-autonomous-ai-agents-agentic-rag/Feeling overwhelmed by the hype around "AI Agents"? This video is your ultimate guide to finally understanding AI Agents and Agentic RAG, even if you're completely new…Thu, 30 Apr 2026 00:00:00 GMTaiai-explainedllmhttps://learnwithmanoj.com/blog/singleton-pattern-explained-anti-pattern-or-essential/https://learnwithmanoj.com/blog/singleton-pattern-explained-anti-pattern-or-essential/Singleton Pattern - the most controversial design pattern in software. Half the developers call it an anti-pattern, the other half use it every day. So who's right?Wed, 29 Apr 2026 00:00:00 GMTdesign-patternsoopsoftware-engineeringcreational-patternshttps://learnwithmanoj.com/blog/prototype-pattern-clone-objects-instead-of-rebuilding/https://learnwithmanoj.com/blog/prototype-pattern-clone-objects-instead-of-rebuilding/Prototype Pattern - when creating an object from scratch is expensive, clone an existing one instead. This is also where shallow-copy vs deep-copy bugs come from.Tue, 28 Apr 2026 00:00:00 GMTdesign-patternsoopsoftware-engineeringcreational-patternshttps://learnwithmanoj.com/blog/builder-pattern-stop-writing-huge-constructors/https://learnwithmanoj.com/blog/builder-pattern-stop-writing-huge-constructors/Builder Pattern - stop writing constructors with 12 parameters. This is the cleanest way to construct complex objects step by step.Mon, 27 Apr 2026 00:00:00 GMTdesign-patternsoopsoftware-engineeringcreational-patternshttps://learnwithmanoj.com/blog/abstract-factory-pattern-the-factory-of-factories-explained/https://learnwithmanoj.com/blog/abstract-factory-pattern-the-factory-of-factories-explained/Abstract Factory Pattern explained with the matching-showroom analogy - the creational pattern for when you need to produce entire families of related objects together.Sun, 26 Apr 2026 00:00:00 GMTdesign-patternsoopsoftware-engineeringcreational-patternshttps://learnwithmanoj.com/blog/factory-method-pattern-vs-simple-factory-pattern-finally-explained/https://learnwithmanoj.com/blog/factory-method-pattern-vs-simple-factory-pattern-finally-explained/Factory Method Pattern vs Simple Factory Pattern - the exact difference most tutorials never make clear, and a classic software engineering interview question.Sat, 25 Apr 2026 00:00:00 GMTdesign-patternsoopsoftware-engineeringcreational-patternshttps://learnwithmanoj.com/blog/ai-masterclass-graphrag-explained-for-complete-beginners/https://learnwithmanoj.com/blog/ai-masterclass-graphrag-explained-for-complete-beginners/Feeling overwhelmed by complex AI data architectures? In this video, we break it down into simple pieces.Tue, 21 Apr 2026 00:00:00 GMTaiai-masterclassllmmachine-learningbeginnershttps://learnwithmanoj.com/blog/ai-masterclass-finally-understand-ai-reranking/https://learnwithmanoj.com/blog/ai-masterclass-finally-understand-ai-reranking/Why is your AI missing the context? In this video, we break down Reranking. We show you the secret 2nd stage of the search pipeline that perfectly orders results from…Mon, 20 Apr 2026 00:00:00 GMTaiai-masterclassllmmachine-learningbeginnershttps://learnwithmanoj.com/blog/ai-masterclass-hybrid-search-for-people-who-hate-math/https://learnwithmanoj.com/blog/ai-masterclass-hybrid-search-for-people-who-hate-math/Feeling overwhelmed by your AI giving you bad search results? In this video, we break down Hybrid Search—the ultimate strategy of combining exact keywords with deep…Sun, 19 Apr 2026 00:00:00 GMTaiai-masterclassllmmachine-learningbeginnershttps://learnwithmanoj.com/blog/ai-masterclass-vector-databases-for-people-who-hate-math/https://learnwithmanoj.com/blog/ai-masterclass-vector-databases-for-people-who-hate-math/Feeling overwhelmed by Vector Databases and SQL? In this video, we break it down into simple pieces.Sat, 18 Apr 2026 00:00:00 GMTaiai-masterclassllmmachine-learningbeginnershttps://learnwithmanoj.com/blog/ai-masterclass-data-chunking-for-rag-explained-simply/https://learnwithmanoj.com/blog/ai-masterclass-data-chunking-for-rag-explained-simply/Feeling overwhelmed by getting your data ready for AI? In this video, we break it down into simple pieces.Fri, 17 Apr 2026 00:00:00 GMTaiai-masterclassllmmachine-learningbeginnershttps://learnwithmanoj.com/blog/ai-masterclass-finally-understand-rag/https://learnwithmanoj.com/blog/ai-masterclass-finally-understand-rag/Feeling overwhelmed by the term "RAG"? In this video, we break it down into simple pieces.Thu, 16 Apr 2026 00:00:00 GMTaiai-masterclassllmmachine-learningbeginnershttps://learnwithmanoj.com/blog/ai-masterclass-hack-proofing-your-ai-prompt-injection/https://learnwithmanoj.com/blog/ai-masterclass-hack-proofing-your-ai-prompt-injection/Feeling overwhelmed by AI security risks? In this video, we break it down into simple pieces.Wed, 15 Apr 2026 00:00:00 GMTaiai-masterclassllmmachine-learningbeginnershttps://learnwithmanoj.com/blog/ai-masterclass-ai-context-limits-explained-simply/https://learnwithmanoj.com/blog/ai-masterclass-ai-context-limits-explained-simply/Feeling overwhelmed when your AI forgets what you said 20 minutes ago? In this video, we break it down into simple pieces.Tue, 14 Apr 2026 00:00:00 GMTaiai-masterclassllmmachine-learningbeginnershttps://learnwithmanoj.com/blog/ai-masterclass-how-ai-reasons-chain-tree-of-thought/https://learnwithmanoj.com/blog/ai-masterclass-how-ai-reasons-chain-tree-of-thought/Feeling overwhelmed by how AIs solve complex math or logic puzzles? In this video, we break it down into simple pieces.Mon, 13 Apr 2026 00:00:00 GMTaiai-masterclassllmmachine-learningbeginnershttps://learnwithmanoj.com/blog/how-to-crack-any-system-design-interview-full-beginner-s-guide/https://learnwithmanoj.com/blog/how-to-crack-any-system-design-interview-full-beginner-s-guide/Most candidates fail system design interviews not because they lack knowledge — but because they don't have a clear framework to structure their thinking.Mon, 13 Apr 2026 00:00:00 GMTsystem-designarchitecturescalabilitybackendhttps://learnwithmanoj.com/blog/ai-masterclass-finally-understand-few-shot-ai-prompting/https://learnwithmanoj.com/blog/ai-masterclass-finally-understand-few-shot-ai-prompting/Feeling overwhelmed by advanced AI prompting techniques? In this video, we break it down into simple pieces.Sun, 12 Apr 2026 00:00:00 GMTaiai-masterclassllmmachine-learningbeginnershttps://learnwithmanoj.com/blog/ai-masterclass-prompt-engineering-for-complete-beginners/https://learnwithmanoj.com/blog/ai-masterclass-prompt-engineering-for-complete-beginners/Feeling overwhelmed by bad AI responses? In this video, we break it down into simple pieces.Sat, 11 Apr 2026 00:00:00 GMTaiai-masterclassllmmachine-learningbeginnershttps://learnwithmanoj.com/blog/ai-masterclass-ai-distillation-synthetic-data-explained/https://learnwithmanoj.com/blog/ai-masterclass-ai-distillation-synthetic-data-explained/Feeling overwhelmed by how complex AIs stay small enough to run on phones? In this video, we break it down into simple pieces.Fri, 10 Apr 2026 00:00:00 GMTaiai-masterclassllmmachine-learningbeginnershttps://learnwithmanoj.com/blog/ai-masterclass-ai-alignment-for-complete-beginners-rlhf/https://learnwithmanoj.com/blog/ai-masterclass-ai-alignment-for-complete-beginners-rlhf/Feeling overwhelmed by AI safety terminology? In this video, we break it down into simple pieces.Thu, 09 Apr 2026 00:00:00 GMTaiai-masterclassllmmachine-learningbeginnershttps://learnwithmanoj.com/blog/ai-masterclass-understand-lora-local-ai-shrinking-models/https://learnwithmanoj.com/blog/ai-masterclass-understand-lora-local-ai-shrinking-models/Feeling overwhelmed by the hardware requirements of AI? In this video, we break it down into simple pieces.Wed, 08 Apr 2026 00:00:00 GMTaiai-masterclassllmmachine-learningbeginnershttps://learnwithmanoj.com/blog/ai-masterclass-fine-tuning-ai-for-people-who-hate-math/https://learnwithmanoj.com/blog/ai-masterclass-fine-tuning-ai-for-people-who-hate-math/Feeling overwhelmed by the term "Fine-Tuning"? In this video, we break it down into simple pieces.Tue, 07 Apr 2026 00:00:00 GMTaiai-masterclassllmmachine-learningbeginnershttps://learnwithmanoj.com/blog/ai-masterclass-finally-understand-how-ai-is-trained/https://learnwithmanoj.com/blog/ai-masterclass-finally-understand-how-ai-is-trained/Feeling overwhelmed by how tech giants actually build ChatGPT? In this video, we break it down into simple pieces.Mon, 06 Apr 2026 00:00:00 GMTaiai-masterclassllmmachine-learningbeginnershttps://learnwithmanoj.com/blog/ai-masterclass-the-truth-about-ai-pricing-and-costs/https://learnwithmanoj.com/blog/ai-masterclass-the-truth-about-ai-pricing-and-costs/Feeling overwhelmed by confusing API pricing tiers? In this video, we break it down into simple pieces.Sun, 05 Apr 2026 00:00:00 GMTaiai-masterclassllmmachine-learningbeginnershttps://learnwithmanoj.com/blog/ai-masterclass-why-ai-can-be-slow-inference/https://learnwithmanoj.com/blog/ai-masterclass-why-ai-can-be-slow-inference/Feeling overwhelmed by latency complaints in your AI app? In this video, we break it down into simple pieces.Sat, 04 Apr 2026 00:00:00 GMTaiai-masterclassllmmachine-learningbeginnershttps://learnwithmanoj.com/blog/ai-masterclass-choosing-an-ai-model-for-complete-beginners/https://learnwithmanoj.com/blog/ai-masterclass-choosing-an-ai-model-for-complete-beginners/Feeling overwhelmed by the hundreds of AI models launching every week? In this video, we break it down into simple pieces.Fri, 03 Apr 2026 00:00:00 GMTaiai-masterclassllmmachine-learningbeginnershttps://learnwithmanoj.com/blog/ai-masterclass-finally-understand-ai-memory-embeddings/https://learnwithmanoj.com/blog/ai-masterclass-finally-understand-ai-memory-embeddings/Feeling overwhelmed by high-dimensional matrices and embeddings? In this video, we break it down into simple pieces.Thu, 02 Apr 2026 00:00:00 GMTaiai-masterclassllmmachine-learningbeginnershttps://learnwithmanoj.com/blog/ai-explained-finally-understand-the-magic-of-transformers-attention/https://learnwithmanoj.com/blog/ai-explained-finally-understand-the-magic-of-transformers-attention/Feeling overwhelmed by Transformer architecture diagrams? In this video, we break it down into simple pieces.Wed, 01 Apr 2026 00:00:00 GMTaiai-explainedllmhttps://learnwithmanoj.com/blog/ai-explained-tokenization-for-non-math-people/https://learnwithmanoj.com/blog/ai-explained-tokenization-for-non-math-people/Ever wonder why AI makes simple math or spelling mistakes? This video demystifies tokenization, breaking down how AI cuts up English words into puzzle pieces.Tue, 31 Mar 2026 00:00:00 GMTaiai-explainedllmhttps://learnwithmanoj.com/blog/ai-explained-finally-understand-how-ai-works-no-code/https://learnwithmanoj.com/blog/ai-explained-finally-understand-how-ai-works-no-code/Unlock the secrets of AI in this masterclass! Part 1 simplifies how AI works, especially Large Language Models like ChatGPT, without any code.Mon, 30 Mar 2026 00:00:00 GMTaiai-explainedllmhttps://learnwithmanoj.com/blog/design-a-scalable-system-from-scratch-full-blueprint/https://learnwithmanoj.com/blog/design-a-scalable-system-from-scratch-full-blueprint/You've learned the pieces. Now let's put them all together and design a real scalable system from scratch — the way it's done in interviews and in production.Sun, 29 Mar 2026 00:00:00 GMTsystem-designarchitecturescalabilitybackendhttps://learnwithmanoj.com/blog/monolith-vs-microservices-which-architecture-should-you-choose/https://learnwithmanoj.com/blog/monolith-vs-microservices-which-architecture-should-you-choose/Microservices are everywhere - but are they always the right choice? Spoiler: most teams adopt them too early, and it costs them.Sat, 28 Mar 2026 00:00:00 GMTsystem-designarchitecturescalabilitybackendhttps://learnwithmanoj.com/blog/rest-vs-websockets-vs-sse-when-to-use-each/https://learnwithmanoj.com/blog/rest-vs-websockets-vs-sse-when-to-use-each/Building a chat app? A live dashboard? A REST API? Each needs a completely different communication model - and picking the wrong one is a costly mistake.Fri, 27 Mar 2026 00:00:00 GMTsystem-designarchitecturescalabilitybackendhttps://learnwithmanoj.com/blog/consistent-hashing-replication-redundancy-how-distributed-systems-scale/https://learnwithmanoj.com/blog/consistent-hashing-replication-redundancy-how-distributed-systems-scale/What happens when you add or remove a server from a distributed system? Without consistent hashing, the answer is chaos.Thu, 26 Mar 2026 00:00:00 GMTsystem-designarchitecturescalabilitybackendhttps://learnwithmanoj.com/blog/cap-theorem-explained-in-6-minutes/https://learnwithmanoj.com/blog/cap-theorem-explained-in-6-minutes/CAP Theorem is one of the most misunderstood concepts in distributed systems - and one of the most asked about in FAANG interviews. Let's fix that.Wed, 25 Mar 2026 00:00:00 GMTsystem-designarchitecturescalabilitybackendhttps://learnwithmanoj.com/blog/database-sharding-indexing-how-big-apps-scale-their-data/https://learnwithmanoj.com/blog/database-sharding-indexing-how-big-apps-scale-their-data/When your database has 500 million rows, queries don't just slow down - they can grind your entire app to a halt. Here's how the biggest systems solve it.Tue, 24 Mar 2026 00:00:00 GMTsystem-designarchitecturescalabilitybackendhttps://learnwithmanoj.com/blog/key-value-document-wide-column-graph-4-nosql-types-explained/https://learnwithmanoj.com/blog/key-value-document-wide-column-graph-4-nosql-types-explained/NoSQL is not one thing - it's four completely different data models. Choosing the wrong one is just as bad as choosing SQL when you shouldn't.Mon, 23 Mar 2026 00:00:00 GMTsystem-designarchitecturescalabilitybackendhttps://learnwithmanoj.com/blog/sql-vs-nosql-how-to-choose-the-right-database/https://learnwithmanoj.com/blog/sql-vs-nosql-how-to-choose-the-right-database/Picking the wrong database early can haunt your system for years. SQL or NoSQL - here's how to make the right call every time.Sun, 22 Mar 2026 00:00:00 GMTsystem-designarchitecturescalabilitybackendhttps://learnwithmanoj.com/blog/fifo-lifo-lru-mru-lfu-cache-eviction-policies-explained-simply/https://learnwithmanoj.com/blog/fifo-lifo-lru-mru-lfu-cache-eviction-policies-explained-simply/Your cache is full. Something has to go. But which item do you remove - and does it even matter? The answer can make or break your app's performance.Sat, 21 Mar 2026 00:00:00 GMTsystem-designarchitecturescalabilitybackendhttps://learnwithmanoj.com/blog/write-through-vs-write-back-cache-which-should-you-use/https://learnwithmanoj.com/blog/write-through-vs-write-back-cache-which-should-you-use/Caching makes systems fast - but it also introduces one of the hardest problems in computer science: keeping your cache and database in sync.Fri, 20 Mar 2026 00:00:00 GMTsystem-designarchitecturescalabilitybackendhttps://learnwithmanoj.com/blog/caching-explained-how-apps-stay-fast-under-heavy-load/https://learnwithmanoj.com/blog/caching-explained-how-apps-stay-fast-under-heavy-load/Without caching, even the fastest databases would crumble under real-world traffic. It's one of the most powerful performance tools in any engineer's toolkit.Thu, 19 Mar 2026 00:00:00 GMTsystem-designarchitecturescalabilitybackendhttps://learnwithmanoj.com/blog/how-load-balancing-works-round-robin-least-connections-more/https://learnwithmanoj.com/blog/how-load-balancing-works-round-robin-least-connections-more/How do systems like Google and Amazon handle millions of users simultaneously without crashing a single server? Load balancing is the answer.Wed, 18 Mar 2026 00:00:00 GMTsystem-designarchitecturescalabilitybackendhttps://learnwithmanoj.com/blog/vertical-scaling-vs-horizontal-scaling-what-s-the-difference/https://learnwithmanoj.com/blog/vertical-scaling-vs-horizontal-scaling-what-s-the-difference/Your app is getting more traffic. Do you buy a bigger server - or add more servers? This decision can make or break your system.Tue, 17 Mar 2026 00:00:00 GMTsystem-designarchitecturescalabilitybackendhttps://learnwithmanoj.com/blog/scalability-vs-reliability-vs-availability-simply-explained/https://learnwithmanoj.com/blog/scalability-vs-reliability-vs-availability-simply-explained/What separates a good software system from a bad one? It comes down to 5 key characteristics - and most engineers can't clearly explain all of them.Mon, 16 Mar 2026 00:00:00 GMTsystem-designarchitecturescalabilitybackendhttps://learnwithmanoj.com/blog/what-is-system-design-beginners-roadmap/https://learnwithmanoj.com/blog/what-is-system-design-beginners-roadmap/A beginner's roadmap to system design: scalability, availability, load balancing, caching, and monolith vs microservices — with the companion YouTube video.Mon, 16 Mar 2026 00:00:00 GMTsystem-designscalabilityarchitecturebackendbeginners