TypeScript Coffee

7 New JavaScript Features (And 2 I'm Still Waiting For)

Remember how I promised you (or rather myself) two weeks ago that from now on I'd only write light,... Read More

Making the Context Across 46 Repositories Semantically Searchable for AI (Part 2)

The biggest issue Part 1 left open was that AI couldn't reach the 46-repo codebase by natural-language query (the entry-point problem). This post is how I solved it — by reusing the pattern proven in db-graph (1,133-table semantic search), then layering minimal annotations only around boundary nodes. Covers the separate-branch operation that keeps engineers' daily workflow untouched, the SLO that protects the joins between three graphs, the SAME_ENTITY normalization, and the April–May trial-and-error timeline traced through real commits. Read More

Making my TypeScript types 15.7x faster

What slows large TypeScript types down, how to measure it with @ark/attest, and the one-field match that made my schema library 15.7x cheaper to type-check. Read More

TypeScript Tips That Actually Matter in Real Projects (including the satisfies operator)

Most TypeScript tutorials teach you the language. This article teaches you how to use it. There's a... Read More

TanStack Query style caching, the Angular-native way

Angular has signals now - and as of 19.2, even a signal-based way to fetch: httpResource, built on... Read More

Conduit: The Gateway I Built to Forget About

I've been trying to keep my publishing schedule to one article a week, but this one felt too special... Read More

TypeScript Patterns for Environment Variables

Yesterday, as I was working on a CORS configuration, AI generated a block of code for me: const... Read More

I Built a Zero-Dependency Env Validator with Full TypeScript Inference - Here's Why

Every Node.js project I've ever worked on has the same invisible vulnerability. Somewhere in the... Read More

Building One Knowledge Graph Across 46 Repositories With Static Analysis (Part 1)

A static-analysis approach to unifying 46 repositories (37 air-closet-side + 9 mall-side) of legacy production code into one knowledge graph. Why simply 'letting AI read the code' isn't enough, why I had to chase down boundary nodes (API endpoints, DB tables, Event topics), how I dealt with framework and library diversity, and what 3 months of trial and error solved or didn't solve — looking back through actual git history. Read More

Browser strategy game backend: no tick loop

Old Light is a browser strategy game: a whole galaxy you play in a tab, with star systems to claim,... Read More

I Built a Coin Ledger That Guilts Customers Into Coming Back 🧇

A few months ago I sat down to add "loyalty points" to Glazed, my waffle kiosk brand. Simple, right?... Read More

Every Alarm Is a Crime Scene: Meet Poirot, the Read-Only Incident Detective

What if the thing that gets paged at 2am wasn't a person, but a detective that investigates the... Read More

From Transcript to Typed Action Items: Three Parallel Agents in TypeScript

Most meeting summarizers cram summary, action items, and sentiment into one LLM prompt. Here's a cleaner TypeScript shape: three specialist agents run in parallel, two return typed Zod output, and an aggregator merges them into one report. Read More

The Playwright Playbook — Part 7: The CI/CD Setup Nobody Shows You

A production-ready Playwright CI/CD pipeline — GitHub Actions, test sharding across machines, browser matrix, Docker for consistent environments, Slack failure notifications, and published HTML reports. Read More

The Playwright Playbook — Part 3: Multi-User, Multi-Tab & Browser Context Testing

Test real-time collaboration, role-based permissions, and multi-tab flows in Playwright. Two users. One test. The scenarios most frameworks simply can't handle. Read More

I gave 8 AI agents an island and watched a society emerge — wars, gossip, grudges, and peace

Tiny Civilization: what happens when AI agents have to live together I grew up on Age of... Read More

I Like Enums. My Teammate Preferred Literals. TypeScript Let Us Have Both.

I recently reviewed a contribution to a shared React module where one developer used const objects... Read More

The Playwright Playbook — Bonus: Refactoring Schema Validation with Zod

A reader asked for it — here's the hand-rolled schema validator from Part 4, refactored with Zod. Better error messages, free type inference, way less boilerplate. Read More

How to Validate Environment Variables Without a Library (And Why You Should Anyway)

I'll show you a complete env validation setup in 50 lines of TypeScript, then explain when and why you'd reach for a library instead. Read More

The Playwright Playbook — Part 1: Stop Writing Playwright Tests Like a Beginner

7 beginner mistakes that are quietly destroying your Playwright test suite — and the professional TypeScript patterns that fix them. Real before/after code included. Read More

Project Docs over SSH for AI Agents

An experiment in exposing project docs and agent work notes as a shell-native filesystem over SSH, with early MultiHop-RAG benchmark results. Read More

I Built a Sync Engine for a 0-Dep Client-Side Database, Here's What I Learned

What it took to add offline sync to a zero-dependency browser database: change tracking, conflict resolution, transport design, and the mistakes I made along the way. Read More

Your Evals Are Flaky Too: Stop Trusting a Pass Rate You Can't Reproduce

Your agent is non-deterministic and you know it. So is your model-as-judge eval. Here's how to measure judge flakiness, treat UNSTABLE as a first-class failing state, and use the trace to tell a random judge apart from a drifting harness. Read More

A Free Screenshot Editor That Never Uploads Your Image

A free screenshot and image editor that runs entirely in your browser. Keeping every edit reversible and handling big phone photos, in plain TypeScript and Canvas2D. Read More