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How things
actually work.

Systems explained the way I wish someone had explained them to me — animated, step-by-step, no prior knowledge assumed. Click into a diagram and watch the request move.

7 articles6 topics~54 min total
Latest

How WebSockets Work

What changes when a connection stops being request/response and stays open — traced through the handshake, and a message neither side asked for.

WebSocketReal-TimeSocket.IOSSE
Read the walkthrough8 min read
Backend9 min read

How to Use Redis in a Node.js API

The cache-aside pattern actually wired into an Express route — connection, helper, invalidation, and the failure handling most tutorials skip.

RedisNode.jsExpress
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Performance8 min read

How Redis Caching Works

Why the second request is always faster than the first — traced through an actual cache miss and an actual cache hit.

RedisCachingTTL
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AI / LLM8 min read

How RAG Actually Works

Why LLMs make things up, and how handing them the right paragraphs first fixes it — indexing and querying, animated step by step.

RAGVector DBEmbeddings
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Auth7 min read

How JWT Works

A signed token instead of a server that remembers you. Traced through a real login and a real API call, request by request.

JWTTokensStateless
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Auth7 min read

How Sessions Work

The cookie is just a pointer — the real record lives on the server. Why that trade-off buys instant logout.

SessionsCookiesRedis
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DevOps7 min read

How CI/CD Works

From a git push to code running in production — every automated gate in between, and why teams trust it enough to ship daily.

CI/CDGitHub ActionsAutomation
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