As soon as Claude Code was released, we were chomping at the bit to see what it could actually do. Not on toy problems, but on our real development work. So we started feeding it real GitHub issues from our open-source and internal repositories — issues created by both community members and Coder engineers — to see how well it could tackle actual engineering problems.

This post covers three of those experiments. For each one, we break down what happened, how close Claude Code got to a working solution, where it struggled, and what we learned. These aren’t cherry-picked success stories. We wanted to see the full range, from wins to failures to everything in between.

Claude Code handled some tasks impressively and stumbled on others, but it’s effective enough that some of our developers use it every day. What makes that more encouraging is that we only gave it GitHub issue links and a few small nudges. It had to explore the repo and figure out the rest on its own.

Task #1: New feature in an internal admin dashboard

Documented by:
Hugo, Growth Engineer at Coder. I contribute to our core product and internal tooling, doing both backend and frontend work.

Task:
We have an internal admin dashboard built in Next.js. It’s about 20,000 lines of code. Among other things, it displays GitHub issues created by our customers. We wanted to make the issues sortable by when they were created and updated.

Outcome (TL;DR):
After prompting Claude Code with the issue title “Allow sorting /customer-issues by creation/update time,” it simply carried out the task. Without additional instructions, it identified the relevant files, added a toggle to the UI for selecting the sort preference, and implemented the sorting logic. I reviewed the code and asked in a single sentence to also allow choosing the sort direction. It implemented that too.

I noticed it had mistakenly flipped the meanings of “ascending” and “descending,” so I edited a single line of code to fix it. While testing the UI, I discovered a bug in the existing human-written implementation: it mutated an object containing the issue list on every React render, causing some text to duplicate after re-rendering. I described the bug as I saw it in the browser and mentioned that I suspected a mutated object was the cause. Claude Code found the faulty code and fixed it. Finally, I asked it to submit a pull request, and it did.

The result was 114 lines added and 28 deleted in a single file.

Learnings:

• Coming into this task, I didn’t expect Claude Code to be useful. My past experience with AI agents, like those in Cursor, was that their suggestions were unhelpful. But Claude Code made the correct changes right away with little direction.
• Using Claude Code was faster than writing the code myself. I wasn’t the original author of the code that needed to be changed, and Claude Code figured out what to do sooner than I could.
• I believe its