Senior Software Engineer – Backend Payments

About the role

We are looking for a Senior Software Engineer to join a fast‑growing ecommerce platform in Belgium. The role focuses on building and evolving high‑scale backend systems that handle global payment, subscription, billing and reporting processes.

Key responsibilities

• Design and develop backend features for high‑availability payment, subscription billing, settlement, refunds and reporting services.
• Build and maintain integrations with external payment processors, card networks and alternative payment methods.
• Architect scalable, secure, service‑oriented systems with a strong emphasis on reliability and performance.
• Debug and resolve complex production issues across money‑movement flows, ensuring minimal downtime.
• Break down large technical initiatives into incremental tasks for agile sprints.
• Participate in architecture, design and code reviews to uphold engineering standards.
• Collaborate with product, risk, finance and compliance teams to implement regulatory and business requirements.
• Improve CI/CD pipelines, testing strategies and deployment processes.
• Mentor junior engineers and promote best practices.
• Identify performance bottlenecks and drive continuous system optimisation.

Required profile

• 10+ years of professional software engineering experience delivering production‑grade SaaS or backend systems.
• Strong expertise in Java and building distributed, service‑oriented architectures.
• Solid experience with SQL (PostgreSQL) and NoSQL databases in production.
• Proven track record designing and implementing RESTful APIs and scalable backend services.
• Hands‑on experience with AWS services such as EC2, S3, RDS, DynamoDB (Lambda a plus).
• Deep understanding of system reliability, monitoring and incident resolution.

Required skills

• Java
• PostgreSQL
• NoSQL databases (e.g., DynamoDB)
• RESTful API design
• AWS (EC2, S3, RDS, DynamoDB, Lambda)
• Distributed systems
• Service‑oriented architecture
• CI/CD pipelines
• Automated testing and deployment