felix-arntz.me

Now

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This is a now page, describing what I’m currently focusing on. I try to keep it up to date.

I can’t believe it’s been 9 months since I joined Vercel! Time has flown by just like that.

I’m incredibly inspired in my role, truly surrounded by šŸs I look up to, in the AI SDK team and beyond.

Vercel really is at the forefront of AI. I love that, and equally do I love that we’re focused on open-source and ecosystem flexibility. No vendor lock-in! The benefits of not working for a model lab, at least for my taste.

The speed at which many of my peers ship is crazy, and so is the attention to UX and DX and all the little improvements to make it even better. I’m learning a lot, every single day.

Coming from the entirely different WordPress and CMS ecosystem to the TypeScript world, I still feel a bit like an imposter. But I feel like I’m finding my way around and making progress working on very cool things:

  • I launched and am maintaining HarnessAgent, AI SDKs relatively new abstraction layer around agentic harnesses (e.g. Claude Code, Codex, Pi), for which I also maintain the adapters. This is where I’m spending most of my time these days since I took on the project in May.
  • I also launched konsistent, a CLI linter that enforces structural conventions in your TypeScript projects. I’m super interested in deterministic requirements verification and enforcement for coding agents, and this is my primary contribution to that very young ecosystem.
  • Other than these two projects, I’m improving other parts of AI SDK (whether provider support or repo tooling), and regularly working on things related to eve and AI Gateway. Plus I’m maintaining a few smaller projects: the AI Gateway plugin for WordPress, a custom set of GritQL plugins for Biome that also fall under coding agent verification, and new-next, an opinionated agent-first Next.js starter via CLI.

I have learned so much in these 9 months, especially about harness engineering. And in the ever-changing ecosystem, what is best practice can shift quickly. Either way, I feel like I’m in the right place to stay on top of it.