Senior Software Engineer (Backend): Ledger - Wallets

As a Senior Software Engineer (Backend) in the Wallets subdomain at BVNK, you own the complete lifecycle of customer wallets across fiat and crypto for merchants, embedded partners, and their customers. This is foundational work: every new product capability, new customer type, and new custody model needs a wallet representation that is accurate, compliant, and scalable. You'll build the infrastructure that makes this possible as BVNK scales into new products and entity structures.

What you'll do

• Design and implement services that manage the full wallet lifecycle: creation, activation, blocking/unblocking, suspension, and termination across fiat and crypto wallets for all customer types.
• Collaborate internally with a wide range of domains including Digital Assets, Fiat, Onboarding, and Billing.
• Build services following BVNK's hexagonal architecture patterns, contribute to HPA tuning, DLQ handling, and performance optimisation for production workloads.
• Participate in on-call rotations, incident response, and production monitoring for wallet-critical services.
• Write well-tested, well-documented code, contribute to architecture reviews and technical design submissions, and uphold BVNK's microservices standards.

What you bring

• 5+ years of backend engineering experience in Java or Kotlin with Spring Boot.
• Strong distributed systems fundamentals: experience building microservices with event-driven architectures (Kafka, SQS), relational databases (MySQL or PostgreSQL), and caching (Redis).
• Experience building or maintaining account or wallet systems where you've managed account/wallet lifecycle, state machines, or financial entity management where correctness and auditability are non-negotiable.
• A solid grasp of domain-driven design and hexagonal architecture, with the ability to model complex domains cleanly, define bounded contexts, and build services with well-defined boundaries.
• API design skills: experience designing and evolving RESTful APIs for both internal services and external customers, with attention to backwards compatibility and developer experience.
• Collaborative and proactive communication style: you work effectively with product managers, operations teams, and cross-domain engineers, and are comfortable operating across time zones in a remote-first setup.
• Production ownership mentality: experience with on-call, incident response, and operational monitoring (Grafana, Prometheus, Micrometer), and you take pride in the reliability of systems you build.
• Familiarity with CI/CD pipelines, infrastructure-as-code, and observability tooling.
• Openness to participate in out-of-hours on-call rotations.

Nice to have

• Experience with multi-tenant architectures and tenant migration patterns.
• Background in embedded finance, BaaS, or payment platforms serving B2B2C models.
• Familiarity with database migrations in high-throughput systems.
• Experience with dynamic validation engines or capabilities/feature-flag systems.
• Experience with stablecoin, crypto, or blockchain-adjacent products.

What we offer

• Fair and competitive salary at every stage of your growth; Bulgaria: €85,000-€95,000 EUR, Spain: €95,000-€105,000 EUR, Poland: 350,000-420,000 PLN (compensation packages are 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. You enable businesses to build financial products, unlock new markets, and move money in seconds across 130+ countries with 40+ licenses for fiat and digital assets globally. Processing billions annually, BVNK empowers enterprises worldwide to send, receive, convert, and settle stablecoins and fiat seamlessly through a single integration, serving industry leaders like Corpay, Worldpay, Deel, and Flywire.