Building Features One Prompt at a Time
How I built Mergify’s new autoqueue in less than an hour a day
A few weeks ago, we released a new feature at Mergify: autoqueue.
It automatically adds pull requests into the merge queue when they’re ready. No more custom automation rules, no more fiddling with YAML — it just works, straight from the merge queue settings.
Here’s the kicker: I coded it.
Yes, me. The CEO. The guy who hasn’t touched production code in years. The guy who usually spends his days on calls, not in GitHub.
And I did it in less than an hour a day, over three weeks, with the help of AI.
Why I Even Tried This
I’ve used Copilot casually before (mostly autocomplete in Emacs), but this time I wanted to go all-in.
Why? Curiosity, mostly. And time constraints. As a CEO, I have close to zero time to code, and this feature wasn’t urgent. So I thought: why not see what happens if I vibe-code it with AI?
How It Worked
The way I interacted with Claude 4 via GitHub Copilot was simple: I explained the feature like I’d explain it to my team in a product story. I added some technical constraints (“use unit tests, not functional ones”).
Then I let the AI go.
It wrote the code. I tweaked less than 5% of it. Once it was done, I sent it for review. I pasted my coworkers’ review feedback back into it. It rewrote. I guided. It iterated.
Did it nail it on the first try? No. Sometimes it forgot instructions. Sometimes it “lost context” after a few iterations and tried to reinvent the test setup it had already learned. That was frustrating — like explaining to a junior dev, except this junior dev has goldfish memory.
But eventually, it worked. The code was merged. Released. In production. Done.
What Surprised Me
I only changed about 5% of the lines myself.
Nobody on the team noticed it was “AI-coded.”
It handled six years of legacy code surprisingly well.
Two years ago this wouldn’t have been possible — the progress is insane.
What It Means
This isn’t about me playing engineer again for nostalgia. It’s about what’s coming.
The quality and quantity bar is about to rise dramatically. AI isn’t just autocomplete anymore; it’s co-construction.
You can ship faster. You can tackle features you don’t fully understand at the start. You can guide at a high level and let the AI grind the details.
But it also raises new challenges. For instance:
How do juniors review AI-generated PRs?
How do teams trust code written by something that forgets your instructions after 10 turns?
(That’s probably another blog post.)
For now, though, I’ll just say this:
I vibe-coded a real feature into existence in less than an hour a day.
It felt like cheating. And I’m amazed.