JavaScript
The event loop visualized step by step, closures with scope chain diagrams, prototype chain lookup, async patterns from callbacks to async/await, browser APIs, value identity, and ES6+ features that changed how people write JS. Six interactive simulators including TDZ, reference vs copy, and prototype chain walkers.
TypeScript
Structural typing, unions, narrowing, generics, utility types, and advanced patterns like branded types and discriminated unions. Interactive demos let you click through type inference and narrowing step by step.
React
How rendering actually works (not what you think), hooks explained through what they replaced, state management decisions, component patterns, and performance. Three interactive demos showing re-renders, hook lifecycles, and memo behavior.
Next.js
Server rendering vs client rendering, the App Router mental model, Server Components vs Client Components, data fetching, caching layers, middleware, and deployment. Interactive rendering strategy picker and cache layer explorer. The framework explained through what problems each feature solves.
Node.js
V8 and libuv under the hood, the event loop’s six phases animated step by step, streams and backpressure visualized, error handling that keeps production servers alive, and Express middleware patterns. Two interactive demos.
Learning Go
Coming from TypeScript/Node, documenting the mental model shift to goroutines and channels. What surprised me, what I had to unlearn, and what clicked faster than expected.
Databases
Pages, storage engines, and B-tree indexes from first principles. How MVCC lets readers not block writers, what isolation levels actually prevent, and the real trade-off between SQL and NoSQL. Interactive index visualizer and transaction anomaly timeline.
Infrastructure
Containers, CI/CD pipelines, observability, and deployment patterns from someone who has debugged OOMKilled containers, fixed flaky pipelines, and chosen the wrong deployment strategy once. Includes an interactive CI pipeline simulator.
Interview Prep
Summary tables for quick scanning + full answers with context. JavaScript, React, TypeScript, and frontend system design questions at the senior level. Every question from the tech-specific articles condensed into interview-ready format.
Playwright
Browser automation explained from locators and actionability to isolated contexts, network control, traces, accessibility, and CI. The journal’s own interactive demos are covered by behavior tests.
Experiments
Rate limiting, saga orchestration, concurrent file processing. Each experiment isolates a real problem, builds a working solution, breaks it on purpose, and documents what happened. Runnable code in the distributed-systems-lab repository.
System Design
Caching, queues, consistency, retries, database design, API design. Short enough to re-read in five minutes, with runnable experiments and interactive visualizations.
Build Notes
Architecture and lessons from real projects. FoxPilot, a profile-driven job discovery engine: why a hardcoded filter was wrong, a two-database bug, and LLM cost engineering.
Pick whatever’s relevant to you right now. Each article is self-contained. If you’re prepping for interviews, every article ends with an “Interview angles” section covering the questions that actually come up and what a strong answer looks like.
If you want to go deep on one stack, the JavaScript, TypeScript, and React sections build on each other (JS covers the foundations, TS adds the type system, React applies both). The Go section is independent.
| Repo | What it is |
|---|---|
| distributed-systems-lab | Runnable experiments in TypeScript and Go. The code that these articles reference. |
| system-design-notes | Structured notes with interactive visualizations for cache stampedes and idempotent retries. |
| reliable-job-platform | Production-style job processing system. The project where these lessons come together. |
| retail-discovery | Live visual retail discovery application built with Java, Spring Boot, React, and computer vision. |