TypeScript Coffee

TypeScript 7 Went Native: What Actually Changes And What Doesn't

Everyone's heard by now that TypeScript "went native." And I keep seeing the same wrong conclusion... Read More

How I Smashed a Bug in a Shared Authentication Library

This is a submission for DEV's Summer Bug Smash: Smash Stories powered by Sentry. This happened a... Read More

Why Does Every AI Agent Still Look Like `while (true) { ... }`?

Most agent runtimes share the same brittle skeleton. Here's what happens when you replace it with an event log. Read More

is-kit Reached 50 Stars ⭐ Here’s How We Use It in Production

Hoi hoi! I'm @nyaomaru, a frontend engineer who is trying to lose weight. 🐖🙀 I maintain a type... Read More

Stale infrastructure context is worse than none

The bug that isn't a bug On Tuesday you attach a dead-letter queue to orders-queue. On... Read More

Restate's Single Binary vs Temporal's Cluster: When the Lighter Engine Wins

Here is a bet that will save you a lot of arguing: pick your durable execution engine on what you... Read More

Fixing Exact Package Search Relevance in npmx

This is a submission for DEV's Summer Bug Smash: Clear the Lineup powered by Sentry. ... Read More

How I Made JavaScript Execution Visual and Rewindable (DSA View View 👀👀)

Hoi hoi! I'm @nyaomaru, a frontend engineer who was recently knocked off my feet by how good the... Read More

Fixing a Silent Cache Bug in npmx.dev

This is a submission for DEV's Summer Bug Smash: Clear the Lineup. The bug npmx.dev is a... Read More

linkedSignal() Writes Back: A Trace Through the Reactive Graph 🔍🚀

Let's be honest: linkedSignal() always had a bit of a split personality. It read beautifully from... Read More

You still write `finally { resource.close() }`. The `using` keyword does it automatically.

You've written this pattern — or something close to it — many times: const timer =... Read More

I tried to compile TypeScript into a native binary with scriptc

TL;DR: I tried to compile the TypeScript 6 compiler into a native binary with scriptc, and I failed... Read More

How I Stopped 429 Retries from Duplicating Successful Batch Jobs

This article is an English translation of the original Japanese article. This is a submission for... Read More

Is Learning DSA Boring? Let's Use DSA View View 👀👀 (Two Sum, Binary Search, and Bubble Sort)

Hoi hoi! I’m @nyaomaru, a frontend engineer who dislikes crowded places, so I'm planning to take a... Read More

Nine green tests and a parser that never worked once

This is a submission for DEV's Summer Bug Smash: Smash Stories powered by Sentry. Two bugs, one... Read More

The bug that differential fuzzing cannot find

I ported a cron parser from TypeScript to Go and ran 36,000 differential test cases with zero divergence. Then I found a bug that no amount of fuzzing could ever have caught — because the output isn't a function of the input. Read More

MCP Went Stateless: Migrating to the 2026-07-28 Spec (and Proving It Works)

📖 TL;DR The 2026-07-28 spec shipped final on July 28, 2026 (RC locked May 21). It is the biggest... Read More

Sandboxing Patterns for Local AI Agents With Filesystem Access

A while back I wrote about running local AI agents on your own code, and it became the most-read... Read More

I Built a Lottery Simulator That Shows You Losing Money for 1000 Years

What I built howtolosemoneyfast.com is a satirical lottery analysis tool. You can simulate... Read More

Cheap Filters First, LLM Last: Running an AI Matcher Inside a Cron Job

I run a small SaaS called Upwork Scout. It watches Upwork around the clock and emails you only the... Read More

My Self-Evolving AI Agent Kept Passing Its Own Tests. The Code Had Never Run

Post #1 covered the birth. Post #2 covered pruning. Post #3 covered cost awareness. Post #4 covered... Read More

I type-check AI-generated SDK code against the real package. Claude refused a third of my Stripe tasks.

I build a small tool called SDKProof. It measures whether AI coding agents write a library's current... Read More

I Chased a Data Bug for an Afternoon. It Was Never About the Data.

This is a submission for DEV's Summer Bug Smash: Smash Stories powered by Sentry. Here's the thing... Read More

Plan Retries Before They Run

A retry policy can look reasonable on its own and still be impossible inside the request that owns... Read More