Felix Geisendörfer
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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actually, almost the same, the trunk parent is missing, but that’s okay if x is a descendant of trunk I guess?
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
Thank you for all your great work on this ❤️
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.
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.
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.
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.
Reposted by Felix Geisendörfer
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
Reposted by Felix Geisendörfer
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 😂.
(This doesn't mean I'm not behind on an incredible backlog of other things ... but one step at a time 😅)
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 🎶
s/way/day/ didn‘t have my coffee yet 😅
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.
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 👍🏻
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.