Backend Engineer

About Jan

Jan is an open-source AI platform, built in public and downloaded over six million times. We put intelligence directly in people's hands: run open models locally or plug in the providers you choose, with your data staying yours. We move fast, open-source what we can, and grow through the people who build and use it. If you want your work to reach millions and stay open, this is the place.

The Role

We are building Jan Router, an enterprise LLM gateway. Think OpenRouter, but for organizations: one gateway in front of many model providers that routes traffic intelligently and gives an org a single place to manage keys, budgets, quotas, usage, and billing. You will bootstrap it from scratch and own the architecture, the first production deploy, and everything from the request proxy to the billing ledger. This is a lean, agent-native setup. Rather than leaning on a large team, you will orchestrate coding and execution agents to ship at team-scale velocity, while keeping the hard backend judgment to build a billing-grade gateway that does not fall over. The router is your primary charge, but not your only one: you will also contribute to the Jan Agent, wiring agent and tool traffic through the same routing, metering, and controls. You are fluent in trade-offs. You know which parts can ship fast and be hardened later, and which parts, like the money path and auth, have to be right the first time. This role suits a Backend or Software Engineer ready to open a new chapter: working closely with a frontier research team and building real AI services from the bottom up, starting at the model level.

What You'll Do

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