The notebook of a backend engineer

Writing about the things that actually ship.

Slow, careful guides on TypeScript, Docker and Node.js — every example runs in a sandbox right here on the page. No setup, no “it works on my machine.”

Read the latest → All posts

~/ A new guide most weeks — TypeScript, Docker & Node.js.

★ Latest · TypeScript

Type-safe environment variables without the boilerplate

Stop sprinkling process.env.FOO! across your codebase. Validate once, at boot, and hand the rest of your app a fully-typed config.

May 28, 2026 · 9 min read

The writing

Latest posts

Everything published so far — new guides land most weeks.

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01 Type-safe environment variables without the boilerplate TypeScript 9 min May 28, 2026 02 Multi-stage Docker builds that actually cache Docker 12 min May 14, 2026 03 Streams in Node: backpressure, finally explained Node.js 15 min Apr 30, 2026 04 Parsing, not casting: trusting data at the boundary TypeScript 8 min Apr 16, 2026 05 A tiny job queue in 60 lines of Node Node.js 10 min Apr 2, 2026

Run it, don't just read it

Every snippet is a sandbox.

The thing that makes these guides different: edit the code and hit run — it executes live in your browser, no setup.

▶ Node sandbox · editable

pipeline.js Node

			
			// A tiny functional pipeline — edit me, then hit Run ▸
const pipe = (...fns) => (x) => fns.reduce((v, f) => f(v), x);

const slugify = pipe(
  (s) => s.trim().toLowerCase(),
  (s) => s.replace(/[^a-z0-9]+/g, "-"),
  (s) => s.replace(/^-+|-+$/g, "")
);

console.log(slugify("  Hello, fake frontend!  "));
return slugify("TypeScript & Docker, 2026");

// A tiny functional pipeline — edit me, then hit Run ▸
const pipe = (...fns) => (x) => fns.reduce((v, f) => f(v), x);

const slugify = pipe(
  (s) => s.trim().toLowerCase(),
  (s) => s.replace(/[^a-z0-9]+/g, "-"),
  (s) => s.replace(/^-+|-+$/g, "")
);

console.log(slugify("  Hello, fake frontend!  "));
return slugify("TypeScript & Docker, 2026");

▶ Container terminal · simulated

multi-stage build

# a multi-stage Dockerfile, simulated. try 'docker build -t app .'

~/app $

Writing about the things that actually ship.

Type-safe environment variables without the boilerplate

Latest posts

Every snippet is a sandbox.

A new guide most weeks.