Armin Ronacher

Creator of Flask; Building at https://earendil.com — writing and talking about system arch, API design and Rust. Love my work? You can sponsor me on GitHub https://github.com/sponsors/mitsuhiko

Account here is largely inactive, moved to Bluesky.

Last Notes

2026-10-25 11:31:29 UTC

The poll so far between Twitter, Bluesky and Mastodon. I think it looks less absurd than last time, but still pretty clear that the base is divided. https://elk.zone/hachyderm.io/@mitsuhiko/117500680388532802
https://media.hachyderm.io/media_attachments/files/117/501/322/054/935/758/original/8a64c7695b5d374a.png

2026-07-16 12:14:24 UTC

After the Linus post I read a bit more how people judge AI on mastodon and I feel like I'm living in a parallel universe.

2026-07-16 06:03:22 UTC

I wonder of this will make some people reconsider their stance or become even more defensive.
https://media.hachyderm.io/media_attachments/files/116/928/138/583/215/221/original/9440ffb8d0c49e96.jpeg

2026-05-24 18:55:28 UTC

Has been a while since I wrote about agentic engineering, so this time around some learnings of maintaining Pi as a junior maintainer to @nprofile…rn5n https://lucumr.pocoo.org/2026/5/24/pi-oss/

2026-04-28 21:16:21 UTC

The post by @nprofile…d2rh gave me the final push to finish my GitHub "obituary". I originally started writing it after the Zig to Codeberg move. It's just a retelling of how I remember OpenSource pre GitHub and what it gave us. https://lucumr.pocoo.org/2026/4/28/before-github/

2026-01-12 09:21:01 UTC

The future is unevenly distributed.
https://media.hachyderm.io/media_attachments/files/115/881/387/017/022/274/original/76f2505e31f60098.png
https://media.hachyderm.io/media_attachments/files/115/881/387/765/259/472/original/711b109f34228280.png

2025-12-29 15:12:46 UTC

If you are a programmer and an AI hold-out, and you have some time off during Christmas: gift yourself a 100 USD subscription to Claude Code and … try it. But really try it. Take a week if you can afford it and dive in. It will change your opinion on these tools.

2025-11-21 22:43:57 UTC

Well, @nprofile…c9r5 reminded of the value of sharing, so here’s the update: agent building is hard. Agent SDKs are tricky, caching is a per-model art, reinforcement can help, isolation saves your sanity, filesystems! New models are “it depends.” https://lucumr.pocoo.org/2025/11/21/agents-are-hard/

2024-09-07 10:16:31 UTC

Not a huge fan of the syntax but I love the feature. Not that I have a much better idea of what the syntax should be so I take it. https://blog.rust-lang.org/2024/09/05/impl-trait-capture-rules.html

2024-09-02 09:25:51 UTC

Is there any reasonable cross-service UI now that can show you Twitter/X, Mastodon and Bluesky in one place and also do cross posting?

2024-06-05 08:08:59 UTC

So after diving into the node internals yesterday to hunt down a memory leak I also learned that setTimeout and async local storage in node is a pretty amazing source of potential memory leaks on their own. Not sure what node can do about it, but the current APIs are not optimal.
If you have a node process that's pretty memory hungry or looks like it's leaking, you might want to read this: https://lucumr.pocoo.org/2024/6/5/node-timeout/

2023-07-02 08:19:54 UTC

- reply

@npub1f6a…pnql for what it’s worth I was always hoping custom tags die out. They are hard to support for alternative implementations and the language is quite expressive that {% call %} and {{ func() }} should work most of the time.