Staff Engineer — Golang (Custody Platform)

Location: OnSite Cyprus / Hybrid / Remote
Team: Work closely with Backend, Security, SRE/Platform, QA, Product Partners: Cryptography/MPC team, Signer/TEE team, UI, Integrations

About us

We build a custody platform for regulated institutions: policy-driven transaction signing, MPC/TEE-based signers, audit-grade eventing, and multi-tenant infrastructure with strict security boundaries. This is a systems role: high-load SaaS backend, correctness-first workflows, hard security constraints, and clear operational ownership (SLOs, observability, on-call maturity).

We’re looking for a Staff Engineer who can design and ship critical platform components in Go, raise the engineering bar, and reliably deliver under real-world constraints (latency, throughput, failures, attacks, audits).

What you’ll do

● Own core backend architecture: lead design for critical services (policy engine, signing orchestration, key lifecycle workflows, custody wallets/accounts, approvals, audit trails).

● Build high-load SaaS systems: multi-tenant isolation, quotas, rate limits, backpressure, concurrency control, and predictable latency under spikes.

● Distributed systems & reliability: idempotency, retries, outbox/inbox patterns, event-driven workflows, saga/state machines, and graceful degradation.

● Security-by-design: least privilege, secret handling, secure service-to-service auth (mTLS/JWT), tamper-evident logs, and audit-ready data models.

● Performance engineering: profiling, load testing, benchmarking, contention analysis, memory/GC tuning, and optimization of hot paths.

● Data & consistency: strong modeling in Postgres (or equivalent), migrations, indexing strategy, partitioning where needed, and clear consistency boundaries.

● Developer productivity & standards: set patterns for Go services, testing strategy, code review quality, and shared libraries; mentor senior engineers.

● Cursor-first workflow: use Cursor for acceleration (refactors, code generation, tests, docs), with disciplined verification, security review, and deterministic outcomes.

Must-have experience

● 8+ years backend engineering, including significant Go (or deep expertise in another systems language + strong Go in recent projects).

● Strong CS fundamentals: concurrency, synchronization, networking, distributed systems, data structures, algorithms, OS basics.

● Proven track record designing high-load, production SaaS (multi-tenant, high availability, incident response, SLOs).

● Hands-on experience with microservices and modern backend stacks: gRPC/HTTP, queues/streams, caching, databases.

● Strong testing discipline: unit/integration/contract tests, testability-first design, deterministic CI.

● Strong observability habits: structured logging, metrics, tracing, debugging production issues end-to-end.

● REQUIRED: regular use of Cursor (or comparable AI coding tool) to speed delivery, with rigorous review, security awareness, and verification.

Nice to have

● Custody / wallets / signing systems exposure (MPC, HSM, TEE, key management, policy/approvals).

● Experience with event streaming (Kafka/NATS/PubSub), exactly-once-ish patterns, replay, and audit/event sourcing concepts.

● Kubernetes + service mesh familiarity; production operations and reliability engineering practices.

● Regulated environment experience (fintech, security audits, compliance-driven engineering).

● Threat modeling and security review participation (abuse cases, attack surfaces, secure defaults).

Soft skills

● Ownership mindset: you ship, you measure, you improve.

● Clear written communication: designs, RFCs, incident write-ups, trade-offs.

● Pragmatic leadership: raises the bar without blocking progress.

● Mentorship: helps others become faster, safer, and more independent.

● Comfortable working in ambiguity and aligning tech decisions with product and risk.

What this role is NOT

● Pure feature “ticket execution” without architectural ownership.

● Fullstack work.

● Research-only cryptography role (you’ll collaborate with cryptography specialists, but your focus is platform engineering).