Haacked

I hate when cars coming out of an alley or driveway don’t stop at the sidewalk for pedestrians. So this time I let the driver know it, “What the fuck!” However I forgot I was on a call with a very confused support person. 🤣

Great post by my colleague about the work we did to reduce latency spikes in our feature flags service built with rust, Tokyo, and rayon: posthog.com/blog/untangl...

Resolving gnarly merge conflicts can be a real tedious chore, until now. Grab a structural semantic merge tool, sprinkle a little AI on it, and you're going to have a lot less headaches. haacked.com/archive/2026...

Credit where credit is due, the new Slack AI bot has been a game changer for finding old slack conversations. I was skeptical, but it actually works for me.

My colleague @dmarticus wrote a great piece challenging the “AI wipes out white-collar jobs in 18 months” narrative. Software development isn’t typing code. It’s ambiguity, constraints, and coordination. That makes it much harder to fully automate: dylanamartin.com/2026/02/21/c...

My shirt keeps telling me I’m absolutely right.

Blogged: One year at PostHog haacked.com/archive/2026...

I know it's just a stochastic parrot, but sometimes Claude can be wryly dismissive:

Blogged: Don't sleep on git worktrees like I did. But using them can be a bit of a chore. But here's a script that makes using git worktrees a breeze: haacked.com/archive/2025...

One more reason I love working at PostHog. Our changelog videos are legit hilarious and entertaining! www.youtube.com/watch?v=xCrf...

My team is hiring a backend focused engineer: posthog.com/careers/back...

Going to see DJ Snake at Drumsheds in London Oct 10!

Check out spelungit: An MCP server I wrote for semantic search of git history. Fully local using a local LLM and sqlite to store embeddings. haacked.com/archive/2025... Plans to use stronger online models in the future, but for now, this works pretty well!

Great post from a colleague: four things in four years at PostHog. Lessons useful at any company: pauldambra.dev/2025/09/four...

At every point in the universe, if you look out into space, the universe is expanding in all directions from that point. Every point in the universe is the center of the universe. So ma’am, in answer to your question if I think the world revolves around me, the universe does.

I think GitHub's CodeQL scanning is broken. It looks like every successive warning includes all the previous warnings.

I think I broke Claude. This video is not sped up.

I was trying to find an old router in my order history on Amazon and how did I order this before I was born?!

I recently adapted GitHub's scripts to rule them all github.com/github/scrip... to PostHog's existing bin scripts. Now it's a part of our handbook: posthog.com/handbook/eng... And there's a repo: github.com/PostHog/scri.... I love the cross-pollination that happens when companies are transparent.

Hey! Looks like I’m an MVP for another year. Much appreciated!

It’s clouds all the way down

I broke the AI again. Clearly Cursor is a fan of LISP.

TIL a fact that’s obvious to any French speaking person but wasn’t to me. If it’s not a crescent shape then it’s not a croissant because croissant is literally crescent in French. It might be a viennoiserie instead.

I’ll be speaking at Techorama. Let me know if you’ll be there!

New bug report opened in the TM SGNL github repo github.com/micahflee/TM...

I heard a scenario: Would you rather receive $1M dollars, or a penny on the 1st such that every penny doubles every calendar day. Of course I pick $1M dollars. What'm I to do with 1 billion pennies? That wouldn't fit in my apt. It'd weigh over 2750 tons! I don't want that headache.

This is a test of skeeting using code.

Do you work on a repo that squash and merges PRs? Notice that `git branch --merged` doesn't work in that scenario? Want a git alias that can clean up merged branches even if they've been squashed? Well I got you! An update to my GitHub Flow aliases: haacked.com/archive/2025...

I now have an answer to the interview question, "What is the biggest technical challenge you've faced?". Answer: Getting a React Native project to build and run locally. I now feel like I can handle any technical challenge!

Wrote some C# today as a palate cleanser. It’s like visiting family after living abroad in exotic places.

TLDR; PostHog is hiring for a bunch of positions: posthog.com/careers I mentioned I started here in Jan: haacked.com/archive/2025... It's a great place to be a software engineer. Lots of interesting work and a great distributed and remote culture.

Finished up some client sdk work in Ruby, and I don't like it as much as I used to. I really miss my types. I may have to look at introducing Sorbet into the library in the future. Next stop is ... oh no ... PHP. God help me.

I’ve been having fun turning my Ghibli images back to photorealistic.

Wrote some Go finally. First impressions, I understand the appeal. It was quick to pick up, simple, and fast. Though I prefer rust for its richer type system.

My son has a group chat with his gamer friends and they made my photo as the group chat image. Don’t know whether to feel flattered or concerned. 😂

Null, the billion dollar mistake. Python: don’t worry, we just call it “None”

Saw someone in this shirt and laughed out loud.

In honor of St. Paddy’s day WeWork is now WeeWork because it’s where the wee folk work. (Please read in your best Irish accent)

Is this what WINNING feels like? Trumponomics in action. Glad I unretired when I did.

Wrote some Rust code today. I don't hate it.

Mobile apps that don’t let you select important text such as a long ass transaction number infuriate me. Yeah, I’m talking about you American Express!

Blogged: Using PostHog in your .NET apps. haacked.com/archive/2025... I just released the 1.0 of the `PostHog.AspNetCore` for adding analytics, feature flags, etc in your web apps.

Looking for folks to give github.com/PostHog/post... a try. I think it’s ready, but could use feedback!

Happy valentine's day! posthog.com/photobooth

When building a library, I highly recommend building out the simplest code samples and writing documentation before you stamp the release as 1.0.0. I'm finding so many dumb usability issues.

"Any time I see 2 strings being compared with lower() it tickles my spidey senses." - things I've said in Slack today.

I’ve been in such a flow state at work that’s it’s actually hard to stop. It’s been a while since I’ve enjoyed work so much!

Code that generates code is some of the most difficult code to write.