Paulus Esterhazy

kaeruct.github.io/posts/2026/0...

We are having a casual Get Together this Thursday 12th of February (I know it's short notice). No talk lined up, just casual chat. clojure.berlin/events/2026-...

@mattpocock.com in your capacity as typescript whisperer, have you blogged about "function parameter bivariance"? I'd be curious if you have practical advice how to avoid the problem I describe in this gist gist.github.com/pesterhazy/4...

Vibecode, not too much, mostly UI

I could use a nice trip to somewhere in Europe or the UK. I'd like to sponsor my trip by doing useful work with your company. I have a lot of skill and experience in software delivery, code craft, and team management. Consider contracting me for a few days. I would love to help.

What's a good folder structure to adopt in a #typescript backend app? gist.github.com/pesterhazy/0...

My team is hiring a Founding Engineer in Berlin (no remote) hi.telli.com/eng

Zod v4 is marketed as having 20x fewer instantiations of tsc... While it's great to see progress, this news makes me hesitant to use it. Why was it doing so much in the first place? All that type-level complexity must have a cost

Logged in to Twitter, the first thing I see is this Pathetic

published beep-boop 0.1.2 - audiovisual feedback for test runs now easy to install via npm github.com/pesterhazy/b...

Map#getOrInsert seems useful

My new book is out: “Exploring TypeScript”. It’s free online! • About 75% of the content is new or rewritten. • Most of the new content is about computing at the type level. exploringjs.com/ts/ #TypeScript

What a wonderful finale, just as cynical as I hoped it would be

Are US tariffs going to affect digital goods like SaaS software?

Updating JS dependencies after 6 months. Nothing works

Of all the bad APIs I've used, Hubspot takes the crown

Teamwork makes the dream work… Along with good architecture, agility, frequent communication (“Yes chef!”), domain driven thinking, a ton of collective experience, knowledge sharing and a lot of passion. But 10x developers? Nah. That’s just over-reliance on one point of failure.

The Boston Public Library is my happy place.

In iTerm, Cmd-Shift-a copies the output of the last command executed. Not sure how I survived so long without knowing this

"What's the advice you would give you to your younger self?" I must have watched this a million times. This is my favorite clip in the entire internet www.youtube.com/shorts/NGJu6...

I'm, *sigh*, going to get better at llm-assisted development. But I want to treat it as a tool to learn, not a short cut. Where should I start? What are the best guides, preferably from people who understand the limitations as well as the upsides?

Wow, solving all SICP problems takes 729 hrs! lockywolf.wordpress.com/2021/02/08/s...

Instead of asking “When is all this going to be done?”, consider asking: “Why can't we release what we have now?”.

I was tired of slow #Emacs lsp completions, which locked up my editor for up to 5s. So I switched to lsp-bridge and now I don't know why I didn't try it earlier. It's so fast, so good, I want to scream it from the rooftops!

For the second time, in two very different jobs, I'm encountering unexpected HTTP 502 errors in a backend API. In each case, the symptom is the reverse proxy reporting "Connection closed unexpectedly" or similar. I suspect the problem in each case to be HTTP keep-alive. Is it just me?

TypeScript enums: use cases and alternatives 2ality.com/2025/01/type... #TypeScript #2ality

And if a test is broken, you have nothing more important to do than figure out why it broke unexpectedly, then make sure the tests & system are in sync and the tests remain predictive & inspiring.

Lynch making quinoa. RIP

Whoever complains about the AWS console hasn't seen the Twilio console yet

Fifteen years in I still make so many mistakes typing/swyping on my iphone. It's driving me up the wall. Is there a cure for typos?

Let's say you know little about telemetry best practices for web apps. What resources (about logs, metrics and traces) would you recommend?

Oh shit everyone is about to circle back

Prediction: this will be the database of 2025. It's a perfect fit for startups

Node.js now supports TypeScript. Here's everything you need to know: www.totaltypescript.com/typescript-i...

Excellent piece on Amazon Aurora DSQL from @ryan-sb.bsky.social. A take that is nuanced and introspective on DSQL’s place in the AWS ecosystem. rsb.io/posts/re-exp...

When I studied philosophy, some students would brag that they only read cutting edge papers from the last decade. A lecturer reacted by asking his students to read only papers older than ten years because they stood the test of time. He had a point

love the Datomic rules of schema growth blog.datomic.com/2017/01/the-...

Renaming database columns without downtime is hard Try to avoid having to do it if you can