Follow a subject.
Every topic pulls together everything about it — the handbook, the system design, the algorithm game, the runnable challenge and the tool — so you can go deep on one subject instead of hopping between 15 separate catalogs.
AI Engineering
RAG & Retrieval
Retrieval-augmented generation end to end — chunking, embeddings, similarity search and ranking — across a system design, a hands-on tool, and runnable challenges.
LLM Engineering
Building with large language models — prompting, decoding, inference serving and cost — from the handbooks down to the softmax that powers every token.
AI Agents & Tools
Agentic systems — tool calling, orchestration and the interfaces that let models act — with the agent system design, the agentic interview handbook, and a tool-schema designer.
AI Evaluation
How you know an AI system actually works — LLM-as-judge, agent evals, and metrics like token-F1 — the half of AI engineering that separates demos from production.
ML Foundations
The math under the models — gradient descent, softmax, embeddings, similarity and ranking — taught as playable labs and runnable challenges, plus the research papers that build on them: reinforcement learning, generative models and graph networks.
AI and Your Career
Will AI replace your role — and how do you become the person it makes more valuable? The AI-era career layer for engineers and professionals: what gets cheap, what becomes the moat, the new stack, and a 90-day plan per role, plus the tool-literacy handbooks, interview prep, and salary data.
Systems & Backend
Distributed Systems
Consistency, consensus, replication and coordination — the CAP-theorem-shaped trade-offs at the heart of every large-scale system — together with the systems foundations underneath them: operating systems, networking, containers and the languages built for this work.
Databases & Storage
Storing data at scale — transactions, isolation, indexing, ledgers and sync — from the concurrency handbook to systems like Dropbox, a payment ledger and a key-value store.
Caching & Performance
Making systems fast — caching strategies, CDNs, rate limiting and low-latency design — with a capacity estimator and the systems that live or die on cache hit rates.
Real-time & Messaging
Pushing data the moment it changes — WebSockets, fan-out, streaming and message queues — across chat, feeds, notifications and collaborative editing.
Forward Deployed Engineering
The trending customer-facing engineering role: discover the problem on site, prototype fast, integrate with the customer’s systems, deploy in their environment, demo, harden, and hand off — everything for becoming a Forward Deployed Engineer.
Developer Utilities
The fast, offline, no-sign-up utilities you reach for daily — decode a JWT, plan a subnet, convert an epoch, generate an ID. Everything runs in your browser; nothing is sent anywhere.
Foundations
Algorithms & DSA
Data structures and algorithms taught as playable games and runnable challenges — graphs, sorting, search and dynamic programming, the half of every interview loop you can practice.
AI for Professionals
AI for people whose job is not software — lawyers, doctors, engineers of the physical world. Workflow recipes, the safety rules that actually matter, and zero code.
Interview Prep
Everything pointed at the interview loop — AI and system-design handbooks, language Q&A, the DSA roadmap and runnable coding challenges in one place.
One idea, seen from every angle.
Every format on one subject
A topic gathers the handbook, the system design, the algorithm game, the runnable challenge, and the tool on a single idea — so you meet it as reading, as a diagram, and as something you actually run, not just one of those.
The same content, a different door
Topics don't duplicate anything — they cross-cut the format catalogs for when you care about the subject more than the medium. Browse by handbook or roadmap when you know the shape you want; browse by topic when you know the thing you want to learn.
Ordered so you can just follow it
Each topic page arranges its pieces from the first explainer to the deep cuts, so you can follow one thread end to end instead of assembling your own path across the site.