Hardcore Go & Distributed Systems Engineering - Interactive Course

A local-first, zero-dependency interactive course site for production-grade Go (1.24 → 1.26) and distributed systems. Built with plain HTML/CSS/JS - no build step, no server, no tracking. Your progress and notes live in your browser's localStorage.

Run it

Just open index.html in any modern browser (double-click it, or open index.html on macOS). That's it.

Everything works over file://. No npm install, no bundler.

What's inside

24 modules across 6 ordered parts, each with at least one interactive, step-by-step animation:

The home page also includes a Distributed Financial Ledger roadmap that shows the final project as one system and links each module to the ledger capability it adds.

• Foundations - Go Runtime & Tooling (beginner-friendly tutorials)
  • F1 · Garbage Collector - tri-color mark & sweep, GOGC, GOMEMLIMIT
  • F2 · Profiling with pprof - CPU/heap/goroutine profiles, flame graphs
  • F3 · Writing Tests - table-driven tests, subtests, coverage, fuzzing
  • F4 · Goroutines & Channels - worker pools, fan-out/fan-in, context
  • F5 · Errors & Context - %w wrapping, errors.Is/As, project layout
• Part 3–6 - Mid → Senior → Staff/Principal (the production systems ramp)
  • Native routing & os.Root, json/v2 & Swiss Tables, runtime.AddCleanup & interning, testing/synctest, sqlc & pgx, PostgreSQL schema/index/migration pitfalls, post-quantum ML-KEM, FlightRecorder & leak forensics, CPU caches, SIMD & Green Tea GC, observability, resilience, Redis, SRE operations, container rollout & governance.

Every module page has:

• In plain terms - a plain-English analogy
• Interactive visualization - numbered steps, play/pause, scrub, step, speed
• Core concepts with syntax-highlighted, copyable Go snippets
• Assignments - graded instantly in your browser: multiple-choice and fill-in-the-blank are checked exactly; predict-the-output and "write code" tasks are checked structurally (rule by rule), not compiled
• AI tutor / ready-made prompt to paste into Claude or Cursor, plus a hands-on Try it yourself or Capstone task
• Common pitfalls and Key takeaways
• A mastery checklist (drives progress) and a local notes field

Tips

• Use the step dots under each animation to jump to a phase; the caption explains it.
• The animations default to 0.4× - click the speed button to slow down or speed up.
• Press space to play/pause the animation, ←/→ to move between modules.
• Toggle dark/light with the ☾ button (top right). Everything is saved locally.

Files

index.html         # shell, loads scripts in fixed order
css/styles.css     # design system, dark + light themes
js/strings.js      # UI chrome dictionary
js/data.js         # English course structure and assignments
js/data.ru.js      # Russian course structure and assignments
js/lessons.js      # English deep-dive lessons and runnable examples
js/lessons.ru.js   # Russian lesson text, inheriting Go code from English
js/animations.js   # 35 canvas animations + timeline engine
js/app.js          # routing, localStorage, rendering, controls