Backend Engineer

We're looking for a Backend Engineer on our founding engineering team. Our backend is primarily Rust. This is a high-ownership role. You'll own problems end-to-end. Right from understanding them, designing the solution, shipping it, and keeping it working in production.

Responsibilities:

• Remote Execution. Every agent session needs a sandbox, a stateful environment with a real filesystem and network. Getting a cold start under 500 ms while keeping hard isolation between tenants is an open problem for us.
• Context over large codebases. Retrieval that actually works on a million-line monorepo, beyond embedding chunks and hoping. Indexing incrementally, ranking across symbol graphs and git history, and staying correct as the code changes underneath you.
• Agent orchestration. Long-running, non-deterministic workflows that fail in interesting ways. Durable execution, resumability, and observability for systems where "retry" isn't always safe.
• Metering and pricing. Usage-based billing for workloads whose cost is unpredictable until they finish. Attribution, real-time budget enforcement, and pricing models that stay honest for both sides. This is largely unsolved across the industry.

Requirements:

• 1-5 years of professional software engineering experience.
• Experience building and maintaining production systems.
• Strong proficiency in Java, Go, C++, Python, Rust, or another mainstream backend language.
• Solid data structures, algorithms, and CS fundamentals.
• Either a good grasp of system design or experience on a genuinely complex production system.
• Strong debugging instincts: you can chase a problem through layers you didn't write.
• Ownership. You don't need everything broken into tickets before you can make progress, and you're comfortable deciding under ambiguity.
• A bias toward learning fast, shipping, and caring about the trade-offs behind your decisions.
• Rust: Our backend is primarily written in Rust, but prior Rust experience is not required.
• Strong engineering fundamentals matter much more than familiarity with a particular language. If you are an excellent backend engineer with experience in Java, Go, C++, or another relevant language, we'll help you ramp up on Rust.

Good to Have:

• Rust-distributed systems, concurrency, or async developer tools and infrastructure, cloud infrastructure and production operations, AI/LLM applications, open-source contributions, and early-stage experience.