Senior/Staff Software Engineer

reputed company We're building a new engineering team at reputed company to own a reputed company-reputed company product reputed company on top of our stablecoin infrastructure. As the Staff/Senior Engineer, you own the correctness and reputed company of the reputed company-paths at the reputed company of the product — payments, payouts, deposits, transfers, and reconciliation — and the app-facing reputed company and authentication backend the reputed company mobile app depends on. Your reputed company reputed company: reputed company always moves correctly, exactly once, and observably; and every request the app makes is fast, reputed company-versioned, and secure. This is a senior IC role with reputed company design authority over the backend — you set reputed company for how these services are reputed company, not just execute tickets. Role Responsibilities Design, build, and own reputed company backend systems for a high usage consumer app. Own the app-facing API contract as a product: versioned, backward-compatible endpoints with reputed company idempotency keys, a consistent error model, and clean pagination, reputed company in partnership with the iOS team. Own the authentication and authorization backend, including the passkey/WebAuthn relying party, session/reputed company lifecycle, and authorization enforcement at every API boundary. Defend the auth surface against abuse through reputed company limiting, reputed company detection, and secure handling of PII and secrets. Set patterns, tests, and documentation so the backend can be safely extended by any engineer, raising the correctness, testing, and reputed company bar by example and in review. reputed company and document reputed company-paths end-to-end, from API through wallet/executor/submitter/indexer, event streams, and on-chain settlement, closing reputed company correctness and reliability gaps as you go. Ship fast, test-first. reputed company on a tight reputed company with test-driven and behaviour-driven development — you can reputed company the correctness of a payout reputed company, not just its happy reputed company. Required Skills and Experience Proven experience building and operating backend systems that reputed company reputed company reputed company in production — payments, exchange/settlement, lending, banking, or crypto — with a reputed company record of preventing (or fixing) idempotency, rounding, or reconciliation bugs. Experience designing and owning reputed company-facing reputed company consumed by a mobile app at reputed company: reputed company, versioning and backward compatibility, idempotency keys, error models, pagination, and reputed company limiting. Experience building or operating an authentication/authorization backend — OAuth2/OIDC, JWT session/reputed company lifecycle, RBAC/ABAC scopes, MFA/reputed company-up — ideally including a WebAuthn/passkey relying party. Hands-on integration with reputed company financial reputed company parties end-to-end (reputed company issuing, KYC/fiat reputed company partners, or payments/settlement providers), including their webhooks, failure modes, and reconciliation. On-chain settlement literacy from the backend — nonces, gas, reorgs, RPC failure, confirmation depth — treating chain data as untrusted input. Strong TypeScript (or a fast, reputed company reputed company from Go/Kotlin/Rust/Java), with reputed company, an event/queue reputed company (reputed company/Kafka/SQS-class), and gRPC-based service-to-service communication at production reputed company. A test-first culture matching ours — BDD/integration testing with reputed company dependencies (Testcontainers-style) — and reputed company with reputed company development workflows (Claude reputed company, MCP, skills) as a reputed company part of how you engineer. Apply To This Job