backend developer for crypto custody

The Vault is an MPC-based crypto custody platform for institutional and retail clients, using threshold signing across HSM and Ledger hardware. It is scaling toward Series A, plans to launch its productized platform in 2026, and publishes original cryptographic research alongside the product.

• Design, write, and ship critical platform components, including the policy engine, signing orchestration, key lifecycle workflows, recovery flows, approvals, audit trails, and multi-tenant wallet and account services
• Lead cross-cutting initiatives in the area of ownership through RFCs, design reviews, and code
• Build high-load, multi-tenant SaaS systems with tenant isolation, quotas, rate limits, backpressure, concurrency control, and predictable latency under spikes
• Implement distributed systems and reliability patterns, including idempotency, retries, outbox/inbox, event-driven workflows, sagas, state machines, replay, and graceful degradation
• Design security-by-default systems with least privilege, secret handling, mTLS/JWT, tamper-evident logs, and audit-ready data models for SOC 2, ISO 27001, and DORA scope
• Profile, load-test, and benchmark systems; analyze contention, tune GC, and build relational models, migrations, indexes, and clear consistency boundaries
• Ship production code with Claude Code, Cursor, and Codex; develop effective prompt and agent patterns for the area; contribute to AI engineering practices and apply AI appropriately across integrations, tests, documentation, and security-critical code
• Set patterns and shared libraries for services in the area and raise standards through code reviews and examples
• Own features end-to-end, from design notes and RFCs through code, tests, observability, rollout, and on-call
• Mentor senior engineers through reviews and written designs

• Strong computer science fundamentals and ability to reason from first principles about concurrency, distributed systems, consistency models, networking, and operating system behavior
• End-to-end ownership of non-trivial production systems, including design, delivery, measurement, improvement, and on-call
• 10+ Years of backend engineering experience, including 3+ years operating at Staff level or with equivalent senior individual-contributor scope
• Strong production experience with a modern systems language such as Go, Rust, Java, C++, or comparable; hands-on Go experience or readiness to ramp up on Go in the first month
• Track record of Staff-level technical leadership through code, RFCs, and influence, without formal authority over teams
• Proven experience building high-load, multi-tenant SaaS in production, including HA, incident response, and SLOs
• Hands-on experience with modern backend stacks, including gRPC/HTTP, queues/streams, caching, relational databases, and Kafka/NATS or equivalent
• Strong testing discipline, including unit, integration, and contract tests, testability-first design, and deterministic CI
• Strong observability practices, including structured logging, metrics, tracing, and end-to-end production debugging
• Production-grade use of modern AI coding tools such as Claude Code, Cursor, Codex, or comparable; able to demonstrate work built with them and critically review AI-generated code
• Будет плюсом: exposure to custody, wallets, or signing systems (MPC, HSM, TEE, key management, approvals); Ledger integration; multiple blockchain ecosystems (EVM and Bitcoin, plus Cosmos, Solana, or others); custom agents, MCP integrations, or in-repo AI workflows; AI-generated code evaluations; production Kubernetes and service mesh; SRE practices; regulated-environment experience; threat modelling and security reviews; familiarity with SOC 2, ISO 27001, and DORA

• Equity participation and full benefits
• Competitive compensation at the Staff engineer band
• Fully remote across any time zone with reasonable overlap with EU/CIS hours
• No people management, sprint mechanics gauntlet, or architecture-by-committee
• AI-forward engineering culture with budget and autonomy for tooling, models, and agents
• Direct peers in cryptography research, security architecture, product, and delivery
• Product approaching Series A with paying institutional customers and a published cryptographic research line