Founding Engineer
Mesmer, Berlin, Berlin, DE
About the job
Berlin · Full-time · YC P25.
We're looking for a founding engineer. This isn't a "join a team" role. It's a "build the team" role. You'll work directly with the founders in a radically transparent environment, no layers, no politics, on a company early enough that what you decide now is how it works for years.
You'll ship product, shape architecture, build the agents, sit with the engineering leaders who use them, and define what engineering excellence looks like here before there is a definition. Some weeks that means going deep in our code. Some weeks it means being the person in the room with a CTO.
We are an AI-heavy company, and we mean it. AI isn't a feature we're adding: it's how we build. We use AI tools aggressively to multiply what a small team can do, and we expect you to push that boundary further. If you've been frustrated by how slowly most teams move, you'll feel at home here.
What You'll Do
- Ship product end-to-end. From data ingestion pipelines to the interface customers interact with daily. You own features from idea to production.
- Build the agents. Active agents that attach to a pull request, a release or an incident and act on their own. Reflective agents that find the pattern across a hundred sessions or a month of review comments, then propose the change for a human to decide.