Full-Stack Engineer (Go + React)

About usThe Vault, an MPC-based crypto custody platform for institutional and retail customers. We run threshold signing with non-extractable key shares across HSM and Ledger hardware, support a growing surface of chains and assets, and are pushing toward post-quantum readiness and SaaS-grade scale. Series A is ahead, the 2026 productized launch is in flight, and we publish original cryptographic research alongside the product work.What you’ll do● Build end-to-end product features across Go backend and React frontend● Design backend services using DDD patterns (bounded contexts, aggregates, domain events), clean layering, and pragmatic architecture● Implement data models and migrations on PostgreSQL, using GORM where appropriate (and raw SQL when it’s the right tool)● Build and maintain REST APIs (and webhooks/event-driven workflows where needed)● Implement frontend flows in React (TypeScript preferred): dashboards, admin workflows, status lifecycles, audit views● Ensure correctness and observability: structured logging, metrics, tracing, and production-ready error handling● Contribute to security fundamentals: RBAC, least-privilege access, safe secrets handling, and audit trails● Own quality: unit/integration tests, contract tests, and CI pipelines● AI-assisted development: use Cursor/Copilot (or similar) daily to accelerate delivery, refactoring, and test generation—while verifying outputs and keeping code cleanMust-have experience● 5+ years building production systems with Go and React● Strong backend fundamentals: concurrency, APIs, reliability, debugging● Hands-on with DDD (not just buzzwords): can model domains and keep boundaries clean● Strong PostgreSQL skills: schema design, indexing, query tuning, migrations● Experience with GORM (or similar ORM) plus comfort dropping to SQL when needed● Frontend proficiency in React (TypeScript preferred), including state management and form-heavy admin UIs● Good testing discipline (Go testing, integration tests; frontend testing basics)● REQUIRED: confident daily use of AI coding tools (Cursor/Copilot/etc.) with disciplined verification and secure practicesNice to have● Event-driven patterns: outbox, retries, idempotency, background jobs● Experience with RBAC/policy engines, audit logs, fintech/compliance workflows● Docker/Kubernetes familiarity● CI/CD ownership (GitHub Actions/GitLab CI), release workflows● Experience with high-security systems (custody, payments, identity)Soft skills● Ownership mindset: deliver features end-to-end with high quality● Clear communication and ability to work across teams● Pragmatic: balances long-term design with shipping● Comfortable in ambiguity and fast iteration