Senior / Staff Engineer - Platform

Platform Engineering at Sei

We're building Sei into a world-class L1 for decentralized finance. This role exists to make the safe path the default path for every engineer on the team - observable, tested, reversible, and fast. You'll be a foundational hire on a small Platform Engineering team with a broad mandate.

What You'll Own

• Infrastructure & scale testing. Build and maintain Docker/Kubernetes harnesses for repeatable stress and scale testing, used by every core team as a pre-release gate. Run our multi-cloud footprint with explicit reliability and cost targets.
• Release engineering & CI/CD. Consolidate CI/CD into reusable, standardized workflows. Own version tagging, hotfix paths, PR review scaffolding, and the full release lifecycle.
• Observability. Single pane of glass for metrics, traces, and logs - correlated by block height, powered by OpenTelemetry. HA Prometheus, ELK, defined SLOs on every critical service.
• Performance & chaos testing in CI. Automated chaos and performance tests gating 100% of releases. Regressions caught before merge, not by users.
• Security & incident response. Run the bug and vulnerability workflow end to end - auditors, Immunefi, triage, postmortems. Every incident produces a new test, metric, or runbook.

What We're Looking for

• 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.
• Security fundamentals. Threat modeling, common vulnerability classes, and how security work integrates into a development pipeline. You don't treat audits as a checkbox.
• 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.
• 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.
• 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.
• 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.

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.