Armin Ronacher
@mitsuhiko.at
Creator of Flask • earendil.com ♥︎ writing and giving talks • Excited about AI • Husband and father of three • Inhabits Vienna; Liberal Spirit • “more nuanced in person” • More AI content on https://x.com/mitsuhiko
More stuff: https://mitsuhiko.at/
More stuff: https://mitsuhiko.at/
Apparently Twitter/X broke my account and now I'm stuck in a mandatory Yubikey re-enrollment flow, that I already completed a while back, but now cannot escape any more.
November 12, 2025 at 6:42 PM
Apparently Twitter/X broke my account and now I'm stuck in a mandatory Yubikey re-enrollment flow, that I already completed a while back, but now cannot escape any more.
I carry this query utility with me from codebase to codebase. I know that a version of this already exists in many libraries, but I really like how simple it is and it also covers identifiers.
November 9, 2025 at 7:52 AM
I carry this query utility with me from codebase to codebase. I know that a version of this already exists in many libraries, but I really like how simple it is and it also covers identifiers.
My oldest and me are making a 3d printed bb8. So far we didn't make it very far, but we wanted to spray paint it, so I needed a cutout. Turns out Claude Code is great at writing OpenSCAD files. Still kinda blown away.
September 28, 2025 at 1:13 PM
My oldest and me are making a 3d printed bb8. So far we didn't make it very far, but we wanted to spray paint it, so I needed a cutout. Turns out Claude Code is great at writing OpenSCAD files. Still kinda blown away.
Interestingly there is more than one bad section of duplicated data. I guess i missed that. But they are all well aligned which is fascinating.
September 20, 2025 at 10:24 AM
Interestingly there is more than one bad section of duplicated data. I guess i missed that. But they are all well aligned which is fascinating.
Is this the optimal way to get pyright to honor the uv virtualenvs?
July 27, 2025 at 12:37 PM
Is this the optimal way to get pyright to honor the uv virtualenvs?
Another great example of Claude helping you figure stuff out. Yesterday I incorrectly assumed Omarchy did not have pam set up correctly because sudo did not work. Reinstall did fix it. But I just locked myself out. Claude confirmed it and told me how to change the lockout policy.
July 23, 2025 at 8:19 AM
Another great example of Claude helping you figure stuff out. Yesterday I incorrectly assumed Omarchy did not have pam set up correctly because sudo did not work. Reinstall did fix it. But I just locked myself out. Claude confirmed it and told me how to change the lockout policy.
Quite frankly the ability of Opus to root cause some more gnarly issues is great. Yes, I could have found this myself (dumb bug caused by a refactor), but still. And it used the available tools perfectly to validate the fix.
When I see it do stuff like this it makes me happy.
When I see it do stuff like this it makes me happy.
July 21, 2025 at 12:49 PM
Quite frankly the ability of Opus to root cause some more gnarly issues is great. Yes, I could have found this myself (dumb bug caused by a refactor), but still. And it used the available tools perfectly to validate the fix.
When I see it do stuff like this it makes me happy.
When I see it do stuff like this it makes me happy.
Speaking of weird corner cases in languages: One of my most enjoyable programming facts is that perl's syntax changes depending on what's in scope. Depending on a condition this is a regex literal or a division.
July 19, 2025 at 1:27 PM
Speaking of weird corner cases in languages: One of my most enjoyable programming facts is that perl's syntax changes depending on what's in scope. Depending on a condition this is a regex literal or a division.
EuroPython was great. Great energy and a lot of AI optimism in individual conversations and generally really good awareness. Was pleasantly surprised. Also we got to see an early cut of the Python documentary!
July 19, 2025 at 6:41 AM
EuroPython was great. Great energy and a lot of AI optimism in individual conversations and generally really good awareness. Was pleasantly surprised. Also we got to see an early cut of the Python documentary!
Let’s do virtual threads. Java did it right.
July 16, 2025 at 3:28 PM
Let’s do virtual threads. Java did it right.
A distinct lack of AI at EuroPython. Going to fix that ;)
July 16, 2025 at 7:12 AM
A distinct lack of AI at EuroPython. Going to fix that ;)
Die Straße ist ein Jahr alt in der Konfiguration. Und man hat es nicht geschafft das Grün zu machen. Und nein, auch wenn die Bäume mal 30 Jahre sind wird das noch nicht grün genug sein.
June 29, 2025 at 12:04 PM
Die Straße ist ein Jahr alt in der Konfiguration. Und man hat es nicht geschafft das Grün zu machen. Und nein, auch wenn die Bäume mal 30 Jahre sind wird das noch nicht grün genug sein.
And then Claude disappeared.
June 23, 2025 at 9:14 AM
And then Claude disappeared.
For converting my internal errors to something for the API, which of those options is what I should be using in Go? (Or am I doing this completely incorrectly and there is a better option)
June 14, 2025 at 9:07 AM
For converting my internal errors to something for the API, which of those options is what I should be using in Go? (Or am I doing this completely incorrectly and there is a better option)
This could have been a tree.
June 13, 2025 at 8:58 AM
This could have been a tree.
Since people ask me about Claude Cost pricing. I'm not sure where it's going, but right now the basic max subscription is a steal. This is for my 100 USD/month subscription which I use with sonnet only. In one week alone I used tokens worth $373.81.
June 11, 2025 at 7:53 AM
Since people ask me about Claude Cost pricing. I'm not sure where it's going, but right now the basic max subscription is a steal. This is for my 100 USD/month subscription which I use with sonnet only. In one week alone I used tokens worth $373.81.
Claude Code is absolutely amazing at figuring out regressions in CI. It studied changelogs, it compared all versions to find the right fix. github.com/mitsuhiko/mi...
June 7, 2025 at 9:26 AM
Claude Code is absolutely amazing at figuring out regressions in CI. It studied changelogs, it compared all versions to find the right fix. github.com/mitsuhiko/mi...
I had Claude Code make 6 commits to this repository someone on lobster mentioned. It made it work, it fixed bugs, it added tests, it extended functionality. I did not review at all because I had no time. Took me 5 minutes of active work. github.com/spc476/NaNoG...
June 5, 2025 at 7:17 AM
I had Claude Code make 6 commits to this repository someone on lobster mentioned. It made it work, it fixed bugs, it added tests, it extended functionality. I did not review at all because I had no time. Took me 5 minutes of active work. github.com/spc476/NaNoG...
One of the patterns I just reintroduced in my codebase is to control all the time keeping. The AI loved to time.sleep in tests which is both brittle and brings down iteration times. Now each thread can time travel and all time functions in the codebase honor it.
June 4, 2025 at 8:13 AM
One of the patterns I just reintroduced in my codebase is to control all the time keeping. The AI loved to time.sleep in tests which is both brittle and brings down iteration times. Now each thread can time travel and all time functions in the codebase honor it.
Pretty big reason for why I'm still on Twitter.
May 28, 2025 at 8:07 PM
Pretty big reason for why I'm still on Twitter.
Someone built an old school keyboard for iOS and it’s about as frustrating as I remember.
May 27, 2025 at 2:22 PM
Someone built an old school keyboard for iOS and it’s about as frustrating as I remember.
It’s Eurovision evening. That is a tradition.
May 17, 2025 at 7:18 PM
It’s Eurovision evening. That is a tradition.