Felix Geisendörfer
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felixge.de
Felix Geisendörfer
@felixge.de
2.5K followers 140 following 140 posts
Working at Datadog on Go Profiling, Performance, OpenTelemetry and more. Before: - Manufacturing Observability at Apple - Co-founder at Transloadit - Node.js Core Dev
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felixge.de
Felix Geisendörfer @felixge.de · 14d
actually, almost the same, the trunk parent is missing, but that’s okay if x is a descendant of trunk I guess?
felixge.de
Felix Geisendörfer @felixge.de · 14d
You can do that in one step if you run:

jj parallelize x::w

same as

jj parallelize x::w
jj new trunk x n p w
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Reposted by Felix Geisendörfer
neallathia.bsky.social
Neal Lathia @neallathia.bsky.social · 17d
"It has, with generative code, become harder and harder to strive towards the lions because the models produce code that is, quite literally, mid" - beautiful post by @vickiboykis.com

newsletter.vickiboykis.com/archive/i-wa...
I want to see the claw
I respect quality software and the people who write it. And, I’ve invested years of my life in working on becoming one of these people (even if the journey...
newsletter.vickiboykis.com
2 4 24
felixge.de
Felix Geisendörfer @felixge.de · 19d
Thank you for all your great work on this ❤️
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Reposted by Felix Geisendörfer
steveklabnik.com
Steve Klabnik @steveklabnik.com · 20d
I see a future in #jj-vcs: steveklabnik.com/writing/i-se...
I see a future in jj
Blog post: I see a future in jj by Steve Klabnik
steveklabnik.com
70 48 390
felixge.de
Felix Geisendörfer @felixge.de · 27d
+1
Reposted by Felix Geisendörfer
prattmic.com
Michael Pratt @prattmic.com · Oct 2
jj v0.34 is out, including Gerrit upload support!

github.com/jj-vcs/jj/re...
Release v0.34.0 · jj-vcs/jj
About jj is a Git-compatible version control system that is both simple and powerful. See the installation instructions to get started. Release highlights Support for uploading changes to Gerrit ...
github.com
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felixge.de
Felix Geisendörfer @felixge.de · Sep 30
I'd love to join one of these again soon, but I'm playing beach volleyball during that time. But usually I play Fridays, so it should work next time.
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felixge.de
Felix Geisendörfer @felixge.de · Sep 28
Watching "stupid jj tricks" from JJ con 2025 live right now. Tune in:

www.youtube.com/watch?v=WWNh...
JJ Conference 2025
YouTube video by GerritForge TV
www.youtube.com
1 6
felixge.de
Felix Geisendörfer @felixge.de · Sep 24
What’s the market rate for corporate emoji smuggling? 🤣
a man in a green plaid shirt is standing next to another man in a black coat
ALT: a man in a green plaid shirt is standing next to another man in a black coat
media.tenor.com
1 3
felixge.de
Felix Geisendörfer @felixge.de · Sep 23
www.youtube.com/watch?v=_eRR...
No one knows what it means, but it's provocative
YouTube video by bentleyguten
www.youtube.com
5
felixge.de
Felix Geisendörfer @felixge.de · Sep 18
Wohooo!!
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felixge.de
Felix Geisendörfer @felixge.de · Sep 17
I need to start a critical path analysis art gallery soon.

The kind of stuff goroutines get up to behind the scenes can be truly fascinating.
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felixge.de
Felix Geisendörfer @felixge.de · Sep 17
Initial prompt + follow-up conversation from cursor: gist.github.com/felixge/b317...
cursor_investigating_goroutine_state_tr.md
GitHub Gist: instantly share code, notes, and snippets.
gist.github.com
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felixge.de
Felix Geisendörfer @felixge.de · Sep 17
Two amazing time savings here:

a) Tracing the call paths of a bunch of runtime functions to a function I know exists, but don't know the name of ("does network wakeup").

b) Writing the final analysis with code snippets and links to the Go code (permalinks at the right Go version).

This is fun.
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felixge.de
Felix Geisendörfer @felixge.de · Sep 17
I'm starting to get better at leveraging AI agents for the kind of low-level stuff I'm doing sometimes.

Example: Asked opus to explain some runtime internals, and then turn the analysis into a nice human-readable markdown output that I can use to explain a code change I'm making to a colleague.
1 4
Reposted by Felix Geisendörfer
golang.org
Go @golang.org · Sep 16
Hi folks, it’s survey time! We’d love to learn more about how you use Go and what could be improved. Share your feedback via our annual developer survey at google.qualtrics.com/jfe/form/SV_.... It should take 10 - 20 minutes to complete, and will be open through September 30. Thank you!

#golang
Go Developer Survey 2025
Share your feedback about developing software with Go.
google.qualtrics.com
32 57
Reposted by Felix Geisendörfer
flassari.bsky.social
Ari Arnbjörnsson @flassari.bsky.social · Sep 11
Profile.
8 160 800
felixge.de
Felix Geisendörfer @felixge.de · Sep 11
My usual workflow is firing off the same query in ChatGPT 5 and Gemini 2.5 Pro these days.

Typically they align, but one answer is better than the other.

But it turns out no amount of AI can solve the "too many chefs in the kitchen" problem 😂.
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felixge.de
Felix Geisendörfer @felixge.de · Sep 11
(This doesn't mean I'm not behind on an incredible backlog of other things ... but one step at a time 😅)
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felixge.de
Felix Geisendörfer @felixge.de · Sep 11
This is a fantastic week. A lot of stuff I've been hoping to accomplish, and wasn't sure if I could, seems to finally be coming together.

And to top it off, Spotify just pulled an incredible "Discover Weekly" playlist out of the hat.

Good times 🎶
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felixge.de
Felix Geisendörfer @felixge.de · Sep 11
s/way/day/ didn‘t have my coffee yet 😅
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felixge.de
Felix Geisendörfer @felixge.de · Sep 11
Even if the solution hadn't come to me, leaving the test case without a fix is a fantastic way to start the way. It gives absolute clarity of focus in the morning.

IIRC @thorstenball.com has been talking about this in the past as well.
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felixge.de
Felix Geisendörfer @felixge.de · Sep 11
Managed to write a reproducer for a non-trivial bug last night.

Old me would have been excited and stayed up late trying to fix it.

These days I know this is the best time to go to sleep. And indeed, the solution came to me while falling asleep.

Wrote it up this morning - works 👍🏻
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felixge.de
Felix Geisendörfer @felixge.de · Sep 6
Your call ovbviously. But I don’t think showing a full use case would overload things.

Everything is a funnel, and every step loses a fraction of users. Clicking into pkg docs for a full example will lose a decent % of potential users IMO.
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