Senior Backend Engineer (Cryptocurrency)

As a Senior Backend Engineer at Arca, you will build and operate backend services for institutional digital-asset infrastructure. You join a small team connecting custodians, cryptocurrency exchanges, and trading firms to support settlement and the reliable movement of financial information and assets. You bring real financial-domain experience and can turn an ambiguous business problem into a safe, working production system.

What you'll do

• Build and operate backend services for settlement, post-trade workflows, and partner integrations, primarily in Python and Go
• Integrate exchange, custodian, banking, and other partner APIs; identify gaps in vendor capabilities and design reliable workarounds
• Model transactions, balances, positions, and financial events with clear consistency rules, auditability, and recovery paths
• Protect financial correctness through transaction isolation, concurrency control, idempotent processing, reconciliation, and testing of failure scenarios
• Work with blockchain integrations and understand smart-contract behavior, transaction confirmation and finality, and the constraints of coordinating activity across multiple chains
• Own work from investigation and technical design through implementation, testing, deployment, monitoring, and production support
• Contribute across the backlog, including infrastructure, compliance controls, and occasional React-based interfaces
• Use Claude Code or comparable AI development tools effectively, while personally reviewing designs, testing behavior, and taking responsibility for the result
• Explain integration architecture and tradeoffs to product, business stakeholders, partner engineers, and customers

What you bring

• Senior-level experience personally owning substantial production backend systems, with specific examples of independent decisions and business impact
• Professional experience building financial transaction systems such as cryptocurrency exchange or custody infrastructure, settlement, post-trade, trading, banking, payments, risk, or accounting systems
• Practical understanding of settlement, reconciliation, and financial data integrity; you can explain how your systems prevent lost, duplicated, or incorrectly recorded funds
• Working knowledge of blockchain and digital-asset transaction mechanics, backed by professional project examples (direct cryptocurrency exchange or custody experience is especially valuable)
• Strong backend engineering ability in Python or Go, or comparable production experience with a credible path to working in this stack
• Strong relational data modeling and SQL skills, including transactions, consistency, and recoverability, plus familiarity with document databases
• Ability to investigate unfamiliar domain problems, navigate an existing codebase, propose solutions, and raise focused questions without waiting for detailed implementation instructions
• Clear professional English and the ability to explain complex financial and technical concepts simply
• Comfort working remotely with a small, collaborative team during U.S. hours and taking responsibility for production outcomes

Nice to have

• PostgreSQL transaction isolation and locking; MongoDB; Go; React
• Smart contracts, multiple blockchains, custody or vault integrations, and on-chain/off-chain reconciliation
• P&L, net positions, netting, counterparty risk, derivatives, prime brokerage, or bank back-office workflows
• SOC 2 controls, secure development, audit trails, infrastructure as code, and operational reliability
• Customer-facing integrations, architecture discussions, technical support, or pre-sales
• Startup experience and a record of becoming productive quickly in a complex business domain

What we offer

• Remote work globally, available during U.S. hours
• Small, collaborative team with shared production-support responsibilities
• Exact overlap hours, weekly schedule, support coverage, compensation, and employment or contractor terms to be discussed during the hiring process

About Arca

Arca builds institutional digital-asset infrastructure connecting custodians, cryptocurrency exchanges, and trading firms to support settlement and the reliable movement of financial information and assets.