Senior/Staff Software Engineer

Ethena Labs is hiring a Senior/Staff Software Engineer (remote) to own the backend of a money-movement product built on its stablecoin infrastructure — payments, payouts, deposits, transfers, reconciliation, plus app-facing APIs and auth backend.

Ethena builds investment products that benefit from the speed, programmability, and compliance advantages of blockchain tokenization. This new engineering team owns a money-movement product built on top of Ethena's stablecoin infrastructure — payments, payouts, deposits, transfers, and reconciliation — plus the app-facing APIs and authentication backend the native mobile app depends on. This is a senior IC role with real design authority over the backend. Responsibilities: - Design, build, and own complex backend systems for a high-usage consumer app - Own the app-facing API contract as a product: versioned, backward-compatible endpoints with client idempotency keys, a consistent error model, and clean pagination, built in partnership with the iOS team - Own the authentication and authorization backend, including the passkey/WebAuthn relying party, session/token lifecycle, and authorization enforcement at every API boundary - Defend the auth surface against abuse through rate limiting, anomaly detection, and secure handling of PII and secrets - Set patterns, tests, and documentation so the backend can be safely extended by any engineer - Trace and document money-paths end-to-end, from API through wallet/executor/submitter/indexer, event streams, and on-chain settlement - Ship fast, test-first, with test-driven and behaviour-driven development

- Proven experience building and operating backend systems that move real money in production — payments, exchange/settlement, lending, banking, or crypto - Experience designing and owning client-facing APIs consumed by a mobile app at scale: contracts, versioning, idempotency keys, error models, pagination, rate limiting - Experience building or operating an authentication/authorization backend — OAuth2/OIDC, JWT session/token lifecycle, RBAC/ABAC scopes, MFA/step-up — ideally a WebAuthn/passkey relying party - Hands-on integration with real financial third parties end-to-end (card issuing, KYC/fiat ramp partners, or payments/settlement providers) - On-chain settlement literacy from the backend — nonces, gas, reorgs, RPC failure, confirmation depth - Strong TypeScript (or a fast path from Go/Kotlin/Rust/Java), with Postgres, an event/queue system (NATS/Kafka/SQS-class), and gRPC at production scale - A test-first culture — BDD/integration testing with real dependencies — and fluency with agentic development workflows (Claude Code, MCP)