Senior Payments Infrastructure Engineer — Crypto, Wallets & Blockchain

Accountabilities: Take ownership of the existing payments backend, understand its architecture and codebase, and complete integration, testing, and production deployment. Complete and optimize payment processing, settlement, reconciliation, and balance-accounting functionality. Develop and maintain reliable financial ledger systems, ensuring transaction consistency, auditability, idempotency, and accurate double-entry accounting. Integrate and manage digital wallets and cryptocurrency payment flows, including deposits, withdrawals, transfers, transaction signing, and secure key management. Implement and maintain institutional custody integrations, particularly Fireblocks or comparable platforms, covering wallet administration, custody APIs, transaction authorization, and security policies. Integrate existing financial services through REST and gRPC APIs, including payment gateways, banking services, fiat on/off ramps, and cryptocurrency exchanges. Troubleshoot distributed systems and resolve integration challenges across microservices, databases, blockchain infrastructure, and external financial services. Build transaction recovery, monitoring, and fault-tolerance mechanisms to handle duplicate processing, partial failures, reconciliation discrepancies, and other exceptional scenarios. Conduct automated integration and end-to-end testing to validate payment flows and ensure production readiness. Deploy and operate secure, scalable infrastructure using cloud and container technologies, with appropriate monitoring and CI/CD practices. Apply security engineering practices across encryption, access controls, secrets management, transaction authorization, and digital asset transfers. Collaborate with backend, infrastructure, blockchain, and financial engineering teams, maintaining clear technical documentation and communication. Make pragmatic engineering decisions that prioritize completing and strengthening existing systems rather than rebuilding components unnecessarily. Requirements: At least 8 years of professional backend engineering experience, including substantial hands-on responsibility for production financial systems, payment infrastructure, cryptocurrency platforms, or digital asset services. Proven experience building and operating financial transaction systems covering payment processing, settlement, reconciliation, and balance management. Strong understanding of double-entry accounting and financial ledger architecture, including transaction consistency, idempotency, auditability, and failure recovery. Production experience with digital wallets and cryptocurrency payments, including deposits, withdrawals, transfers, transaction signing, and secure key management. Experience integrating Fireblocks or comparable institutional custody platforms, including custody APIs, wallet administration, transaction authorization, and security controls. Advanced proficiency in Rust, Go, or another high-performance backend language, with the ability to work effectively within Rust-based microservices. Strong knowledge of distributed systems, REST and gRPC APIs, asynchronous processing, concurrency, fault tolerance, and event-driven architectures. Solid database engineering experience with PostgreSQL or comparable transactional databases, including ACID guarantees, concurrency control, and data integrity. Production experience with AWS, Docker, CI/CD pipelines, monitoring, and infrastructure security for mission-critical services. Deep understanding of blockchain transaction infrastructure, cryptographic signing, wallet architecture, and secure digital asset transfers. Experience integrating third-party financial services, such as payment gateways, banking APIs, fiat on/off ramps, or cryptocurrency exchanges. Strong security engineering knowledge covering encryption, access controls, secrets management, transaction authorization, and financial-system security practices. Ability to independently investigate unfamiliar codebases, own complex production systems, resolve integration issues, and deliver reliable solutions without unnecessary redesign. Experience with automated integration and end-to-end testing of financial transactions, including duplicate processing, partial failures, reconciliation discrepancies, and recovery scenarios. Strong technical documentation, communication, and cross-functional collaboration skills. An adaptable, entrepreneurial mindset, with the ability to work through ambiguity, changing priorities, and the evolving needs of an early-stage venture. Creative problem-solving skills and the confidence to challenge existing approaches and propose practical improvements. Highly preferred: Direct production experience with Fireblocks and TigerBeetle; hands-on Rust development in financial or high-throughput distributed systems; Solana and SPL token integrations; experience with cryptocurrency exchanges, payment orchestration, custody infrastructure, or treasury systems; familiarity with KYC/AML, PCI DSS, and financial services compliance; and a track record of deploying financial infrastructure that handles real customer funds at production scale. An interest in football and international sports is an advantage. Benefits: Opportunity to help build a global technology platform and take meaningful ownership of critical financial infrastructure. Entrepreneurial environment with autonomy, independence, and the opportunity to influence technical decisions. Deferred compensation arrangement: compensation is agreed upon but payments are deferred until funding is secured. Once funding is secured, the arrangement is intended to transition to a competitive, normalized salary, together with equity and OleX token ownership. Participation in the long-term ownership and potential success of the venture. The deferred compensation model applies across the team, including the founder. This opportunity involves early-stage startup risk and uncertainty around the timing of funding and compensation payments. The role is associated with Austin, Texas, and requires some travel. The position is listed for the United States; specific remote or office arrangements are not detailed.