Tiny explainers grouped by topic. Spend less time Googling, more time building.
A practical, production-safe guide to CPU and memory profiling across Node.js, Python, and Go with real commands, code snippets, and a field guide to reading flamegraphs.
Trade-offs, pitfalls, and production-ready code with SQL, Node, FastAPI, MongoDB and Elasticsearch examples.
Fixed/sliding windows, token & leaky buckets, GCRA, and real-world implementations (Redis, NGINX, Envoy). Covers headers, bursts, backoff, multi‑DC, and tuning.
Freshness, validators, and directives: Cache-Control, ETag/Last-Modified, Vary, s-maxage, stale-while-revalidate, immutable. Patterns for APIs, HTML, and assets—plus CDN tips.
A practical mental model of tasks vs microtasks, when the browser renders, and patterns to keep 60fps: rAF, chunking, debouncing, and avoiding microtask traps.
Multi-stage builds, cache-friendly layering, non-root users, and sane defaults for ENTRYPOINT/CMD, healthchecks, and secrets. Copy‑paste patterns for Node, Python, and Go.
A practical mental model for indexes, with copy‑paste patterns for B‑tree, composite order, covering, partial, and expression indexes—plus when **not** to index.
A concise, modern walkthrough of the path from address bar to pixels: DNS lookup, HTTP/3 & TLS 1.3 handshakes, CDNs & caching, request/response, and the rendering pipeline.
A fundamental database performance problem: why N+1 happens, how to spot it, and fixes with eager loading/batching in popular ORMs (Django, Rails, Prisma/Sequelize, SQLAlchemy).
Concurrency is about dealing with lots of things at once; parallelism is about doing lots of things at once. Here’s the mental model, practical examples, and when to use each.
A fast primer on in-memory, distributed, and CDN caching—what they are, when to use each, and how they boost latency, throughput, and cost efficiency.