We are hiring a Senior Backend Engineer to take ownership of core backend architecture at Money EU, a payment gateway and payment orchestration platform handling real-money transactions across multiple countries.
About the Role
This is a mission-critical engineering role for an experienced backend engineer who can design, build, and operate banking-grade systems. You will own complex payment flows, PSP integrations, routing and orchestration, settlement and reconciliation, security, reliability, and performance while helping define the technical direction of the platform.
Key Responsibilities
- Design and build highly available backend microservices using Java and Spring Boot.
- Own integrations with global Payment Service Providers (PSPs) such as Redsys, D24, CoinsPaid, and similar providers.
- Design end-to-end payment flows including authorization, capture, refunds, callbacks, retries, and failure handling.
- Build robust payment routing and orchestration logic across multiple PSPs, currencies, countries, and transaction scenarios.
- Design and implement settlement and reconciliation systems that ensure accurate merchant payouts.
- Own secure transaction handling using HMAC/AES-based encryption, signatures, and secure API communication.
- Design for idempotency, consistency, retries, timeouts, fault tolerance, observability, and recovery across money-moving flows.
- Optimize API and database performance for high-scale transaction volumes using MySQL/PostgreSQL and effective query design.
- Lead debugging and incident investigation for complex production issues involving financial transactions.
- Drive architecture decisions, technical standards, code quality, testing strategy, and engineering best practices.
- Collaborate closely with frontend, DevOps, QA, product, and other engineering teams to deliver production-ready features.
- Mentor junior and mid-level engineers and raise the team's technical capabilities.
Why This Role Is Critical
- You will be directly responsible for systems handling sensitive financial transactions.
- Every architectural and implementation decision can affect money movement, merchant balances, and customer experience.
- You will help shape the core architecture that powers Money EU and its expansion into new markets.
- You will own PSP integrations and payment infrastructure that can directly enable new products, markets, and revenue streams.
Skills & Requirements
- Strong professional experience with Java and Spring Boot in production.
- Deep understanding of REST APIs, microservices, distributed systems, and asynchronous flows.
- Strong experience with MySQL/PostgreSQL, indexing, query optimization, transactions, and data consistency.
- Strong understanding of payment processing, financial transaction lifecycles, or comparable high-integrity systems.
- Hands-on experience integrating third-party payment providers or other mission-critical external APIs.
- Strong knowledge of security concepts including HMAC, AES, signatures, authentication, and secure API communication.
- Experience designing for idempotency, retries, concurrency, fault tolerance, and high availability.
- Strong debugging, incident response, performance tuning, and analytical skills.
- Ability to make sound architecture decisions and take end-to-end ownership.
- Strong communication and mentoring skills in a fast-paced startup environment.
Nice to Have
- Experience with card processing flows and 2D/3D Secure.
- Experience with payment routing, settlement, reconciliation, chargebacks, or fraud-related systems.
- Experience with AWS, Docker, Kubernetes, CI/CD, and production deployments.
- Experience with Kafka, RabbitMQ, or other messaging/event-driven systems.
- Experience designing systems for multi-country and multi-currency payments.
- Prior fintech, payments, banking, or payment-gateway experience.
Job Details
Employment
Full-time