Senior Software Engineer (Backend): Crypto Payments

As a Senior Software Engineer (Backend) at BVNK, you'll join the Crypto Payments Orchestration team at the heart of the platform. This team owns the layer that makes crypto and stablecoin payments behave like simple, programmable money movement, covering pay-ins, pay-outs, payment channels, payment links, and cross-currency flows between fiat and stablecoins. You'll work in a small, autonomous team that owns its services end to end, helping scale a business-critical payments platform used by enterprises across 130+ countries.

What you'll do

• Design, build and run high-throughput backend services that orchestrate crypto pay-ins, pay-outs, conversions and transfers across many assets and blockchain networks.
• Build and evolve clean, versioned, well-documented public and internal APIs that merchants and partners use to accept, convert and send money.
• Ensure every payment is processed exactly as intended using proven patterns such as idempotency, transactional outbox, retries and dead-letter handling so financial events are never lost or duplicated.
• Find and fix bottlenecks in hot paths, database access and service-to-service calls to scale the platform with fast-growing payment volumes.
• Help modernise core services by breaking up legacy components into clear, modular, domain-aligned boundaries while keeping a live payments platform running safely.
• Design and build asynchronous, event-driven workflows with clear contracts between services and other domains.
• Work closely with Product, other engineering teams, Compliance and Operations to deliver new payment capabilities, assets and networks end to end.
• Own your services in production: monitor, alert, take part in on-call, and lead incident response and root cause analysis that leaves systems stronger.
• Use AI coding tools and agentic workflows in your day-to-day work, share what works with the team, and mentor other engineers through code reviews, pairing and technical design.

What you bring

• Solid professional experience as a backend engineer, building and running production systems at scale.
• Strong proficiency in Java (ideally Java 17+) and Spring Boot.
• Hands-on experience with microservices and event-driven architectures using message brokers such as Kafka or SQS, including patterns like transactional outbox, idempotency and eventual consistency.
• Strong experience with relational databases such as MySQL or PostgreSQL, including schema design, indexing, query tuning and safe migrations.
• Experience with AWS, Docker and Kubernetes, CI/CD pipelines and modern observability tools for metrics, tracing and logging.
• Experience building payment, banking or other financial systems where correctness, auditability and reliability matter.
• A strong testing mindset across unit, integration and contract tests, and a passion for clean, maintainable, well-designed code.
• You are an early adopter of AI coding tools and agentic workflows, using them to design, build and test solutions, not just to write snippets.
• You take ownership from idea to production, communicate clearly with technical and non-technical colleagues, and move fast in a fast-growing environment.
• You are open to participating in an out-of-hours on-call rota.

Nice to have

• Experience with Kotlin.
• Experience with caching such as Redis.
• Experience with stablecoins, blockchain networks, crypto wallets or crypto payment processing.
• Experience applying domain-driven design, modular architecture or large-scale refactoring of legacy services.
• Experience with workflow engines such as Temporal, or with building rule engines and scheduling systems.

What we offer

• Competitive salary: €70,000-€110,000 EUR (Bulgaria), €85,000-€110,000 EUR (Spain), or 250,000-480,000 PLN (Poland), based on candidate experience and relevant certifications.
• Flexible working hours with hybrid working at its heart.
• A flexible approach to holiday.
• Opportunities to travel to offices around the world.

About BVNK

BVNK is the stablecoin-powered financial stack for enterprises, now part of Mastercard. The company enables businesses to move money in seconds across 130+ countries with 40+ licenses for fiat and digital assets globally, processing billions annually. Trusted by industry leaders like Corpay, Worldpay, Deel and Flywire, BVNK delivers the infrastructure that makes stablecoins and fiat usable within the financial systems enterprises already rely on.