Sei Labs - Senior / Staff Engineer

• 5+ years building production systems at scale. You've designed and shipped infrastructure that other engineers rely on, and you understand it end to end — not just the surface API. • 5+ years building production systems at scale. • Security fundamentals. Threat modeling, common vulnerability classes, and how security work integrates into a development pipeline. You don't treat audits as a checkbox. • Security fundamentals. • Distributed consensus understanding. You can reason about consensus protocols at the algorithmic level — safety vs. liveness, fault assumptions, the failure modes that show up in practice. You've debugged something non-trivial at this layer or studied it deeply enough to. • Distributed consensus understanding. • Benchmarking & performance bottleneck analysis. You design benchmarks that isolate variables. You profile under realistic load. You can walk into an unfamiliar system, find the bottleneck, and explain why it's the bottleneck before proposing a fix. • Benchmarking & performance bottleneck analysis. • Live incident response. You've operated systems where outages had real consequences. You triage under pressure, communicate clearly, and turn postmortems into structural fixes that don't quietly expire. • Live incident response. • End-to-end systems thinking. You've built systems, not just glued tools together. You have opinions on monitoring stacks, what belongs in CI vs. CD vs. runtime, and when to reach for chaos testing — and you can defend them. • End-to-end systems thinking. • Bonus • Blockchain or web3 infrastructure experience, especially with consensus, mempool, or storage layers. • Multi-cloud cost programs that didn't compromise reliability. • Experience integrating AI-assisted security tooling into a development pipeline.