Senior Backend Engineer

Our client is a fast-growing fintech company building next-generation payment and infrastructure solutions for high-risk and highly regulated industries. They are looking for a Backend Engineer with strong expertise in Java/Kotlin and extensive experience in the payments ecosystem, particularly in card payment gateways.

If you have a passion for building high- performance systems and possess deep knowledge of payment gateways and card transactions, we’d love to hear from you.  You will play a crucial role in designing, developing and maintaining their backend systems to ensure seamless and secure payment processing for their clients.

• Design, develop and maintain backend systems for high-scale, high-availability payment solutions.
• Build, enhance and optimize payment gateways specifically for card transactions, including support for 3DS flows.

• Work closely with the product team to design solutions that meet business needs within the payments ecosystem.
• Collaborate with cross-functional teams to develop and maintain a robust microservices architecture.

• Solve complex technical problems to ensure system performance, reliability and scalability.
• Analyze and optimize system performance, focusing on transaction throughput and latency.

• Write clean, maintainable and testable code with a focus on quality and best practices.
• Ensure codebase adheres to industry standards and is well-documented.

• Minimum 5 years of proven experience in backend development.
• Extensive experience with card payment gateways and handling card transactions including 3DS flows.
• Strong expertise in Java and/or Kotlin programming languages.

• Solid knowledge of the Spring Framework (e.g. Spring Boot, Spring WebFlux).
• Proven experience in building and maintaining payment gateways focused on card transactions within the payments ecosystem.
• Experience with microservices architecture and developing distributed systems.
• Expertise in designing and maintaining high-scale, high-availability systems.
• Strong understanding of database systems, both SQL and NoSQL.

• Strong problem-solving skills and a collaborative mindset.
• Excellent communication skills and the ability to work effectively in a team environment.
• Must know English very well.

• Familiarity with messaging systems like Kafka, RabbitMQ or similar.
• Experience with monitoring tools such as Prometheas, Grafana or equivalent.
• Knowledge of cloud platforms (e.g. AWS, GCP, Azure) and container orchestration (e.g. Kubernetes).
• Experience with PCI DSS compliance and secure payment system practices.
• Knowledge of payment processing standards such as EMV, PSD2 or similar.
• Familiarity with OpenAPI, gRPC or Protobuf.
• Hands-on experience with DevOps practices and CI-CD pipelines.