About the role
The Agent Runtime is the heart of Sigil: every tool call, retry and model fallback passes through it. You’ll join the three-person runtime team and own large parts of the scheduler, the execution sandbox and the trace pipeline.
What you’ll do
Design and ship features in the Go and Rust services that execute agent runs
Cut p99 scheduling latency and keep 99.99% uptime honest
Build retry, fallback and budget-cap logic that customers can trust at 3 AM
Write design docs, review code and share on-call with the team
What we’re looking for
6+ years building distributed backend systems in production
Deep experience with Go, Rust or a similar systems language
Comfort with queues, Postgres and observability tooling
Clear async writing: most decisions here start as a doc
Nice to have
Experience running LLM workloads or agent frameworks
Contributions to open-source infrastructure projects