Senior Go Engineer (6 month project)

We are looking for a Senior Backend Engineer to join a large-scale issuer processor migration programme within the payments domain. The role is focused on building and integrating high-volume backend systems, supporting complex platform migrations, and ensuring the reliability of business-critical services throughout the programme lifecycle. Location Denmark is the preferred location for this role. What you'll be working on - Design, develop, and maintain backend services using Go/Golang - Build integrations between complex client and vendor platforms - Work with transaction processing systems, APIs, and event-driven architectures - Contribute to distributed systems and microservices-based solutions - Support technical integration activities across multiple platforms - Perform technical analysis related to migration and integration initiatives - Participate in testing throughout different stages of the migration programme - Investigate and resolve technical issues arising during integration and migration - Work in cloud-native environments using modern engineering practices - Help ensure the stability, reliability, and continuity of high-availability, business-critical systems - Collaborate closely with client, vendor, and engineering teams throughout the programme lifecycle Requirements What we're looking for - Strong commercial experience with Go/Golang - Proven experience designing and building complex backend systems - Solid understanding of distributed systems and microservices architecture - Hands-on experience with event-driven platforms such as Kafka - Strong knowledge of API design and system integrations - Experience working on large-scale migration or integration programmes - Experience with cloud-native environments and modern engineering practices - Ability to work with high-volume, high-availability backend services - Experience troubleshooting complex technical issues across integrated systems - Strong collaboration skills and confidence working with both client and vendor teams Relevant domain experience Experience in any of the following areas would be highly valuable: - Card payments - Issuer processing - Banking - Fintech - Transaction switching - Payment infrastructure - Other transaction-heavy or real-time processing environments The ideal candidate combines strong backend engineering expertise with practical experience working on complex integrations and migration programmes, particularly in environments where reliability, scalability, and continuity are critical.