Senior Data Migration Engineer (Java)

As a Senior Data Migration Engineer, you will be a core execution member of the dedicated migration squad. You will work hands-on across the full migration lifecycle – from extraction and mapping through conversion, validation, and cutover – while also actively building the tooling and accelerators that make future migrations faster and safer (e.g.: artifact observability, version-controlled mapping pipelines, automated validation checks, and reusable migration templates). This is not a maintenance role: you will shape the process, own the tooling, and directly influence delivery velocity. 

Tech & Tool Stack

Java

PostgreSQL

ORACLE

MSSQL

AWS

• End-to-end ownership of complex, high-stakes technical deliveries. 

• Direct contribution to tooling that will outlive the programme and be reused across 50+ customer migrations.

• A growing role: as the programme industrializes, senior engineers are expected to mentor and technically lead parallel migration teams.

• Exposure to a full modern stack (Java 21 / React / PostgreSQL / AWS) alongside legacy Smalltalk systems.  

• Long-term engagement with clear phase gates and the possibility to grow into a Lead Engineer role. 

Data Migration & Legacy Systems experience 

• Proven experience with large-scale data migration projects: ETL or systems integration on enterprise-scale projects, transformation pipelines, cutover planning. 

• Experience working with XML-based data transformation (mapping files, XSLT, or equivalent config-driven ETL).

• Proven ability to diagnose complex migration errors under time pressure: root-cause analysis, staging data fixes, re-run coordination. 

• Experience coordinating with business stakeholders during UAT and cutover; clear written and verbal communication in English. 

• Experience with legacy database analysis: reverse-engineering un(der)documented schemas, understanding data semantics and relationships without complete documentation and dealing with corrupted or ambiguous data or metadata. 

Technical Skills 

• Comfortable working with SQL at an advanced level: complex queries, schema analysis, data profiling, and diagnosing data quality issues. 

• Strong proficiency in SQL across at least two of: PostgreSQL, Oracle, SQL Server, DB2. 

• Solid Java skills (Java 21 ecosystem preferred); comfortable building and extending internal tooling – data pipelines, automation scripts, validation frameworks – with clean, testable code. 

• Familiarity with Git workflows, CI/CD pipelines, and infrastructure-as-code practices.  

• Good exposure to cloud environments, ideally AWS infrastructure and services. 

• Docker: confident setup, troubleshooting, and local environment management. 

Domain & Governance 

• Rapid domain understanding: ability to quickly absorb unfamiliar, regulated business domains.  

• Governance mindset: documenting decisions, maintaining audit trails, getting formal client sign-off.  

• Experience working with subject matter experts to define and validate data transformations and mappings. 

Mindset & Working Style 

• Ability to manage multiple concurrent workstreams. 

• Clear communicator: able to explain architectural and domain modelling decisions to both technical and non-technical stakeholders. 

• Resilient and persistent under pressure: comfortable working with tight deadlines and high client expectations. 

• Actively uses AI-assisted tools (e.g. ChatGPT, Claude, GitHub Copilot or similar) as part of daily development and problem-solving workflow – we expect AI tools to be a natural part of how you work. 

• Exposure to Smalltalk or ObjectStudio.  

• Familiarity with S3-compatible object storage, artifact lifecycle management, or observability tooling (dashboards, trend analysis). 

• Experience with cloud-native deployments on AWS; understanding of multi-tenant SaaS architectures. 

• Debt management, financial services, or accounts receivable domain experience is a significant advantage. 

• German language skills (B2+).