Senior Java Developer, Spain

Project description We have an ambitious goal to migrate a legacy system written in HLASM (High-Level Assembler) from the mainframe to a cloud-based Java environment for a big airline company in the USA. Responsibilities We are looking for an experienced Senior Software Engineer who can help perform the migration of the client platform: Write Java and Python code following the new architecture. Troubleshoot, debug, and resolve issues within the new Java system. Collaborate with client teams, to ensure alignment with project goals and deliver high-quality solutions. Maintain and fine-tune Gen AI application that supports the migration process. Skills Must have Proficiency in Java development (5 years). Proficiency in Python development (5 years). Experience with any cloud platforms and services. Deep understanding of enterprise application architecture patterns. Strong problem-solving and debugging skills. Experience of work in distributed teams, with US customers. Excellent communication skills for collaboration with the client teams. Nice to have Familiarity with large-scale system migrations and modernization efforts. Experience with HLASM or other low-level programming languages. Familiarity with Generative AI. Prior experience working in the banking or financial services industry. Knowledge of performance tuning and optimization in cloud environments. Other Languages English: B2 Upper Intermediate Seniority Senior

Location: Madrid, Community of Madrid, ES

Posted Date: 10/25/2025