Senior Java ETL Data Engineer

About the role

3E is looking for a Senior Java ETL Data Engineer to own the technical direction of its ETL engine, which processes near-real-time data from more than 20 million devices across utility-scale solar and wind sites. The role sits in the Product Engineering organisation, in a small cross-functional team of 2-3 engineers reporting to an Engineering Manager, with English as the working language. It is a senior individual contributor position.

Key responsibilities

• Design, develop and operate the Java ETL engine, from conception through to production operation
• Integrate the engine with S3-compatible object storage and streaming infrastructure, choosing and justifying technologies
• Balance real-time and batch processing trade-offs on evidence
• Lead quality and reliability through code review, testing and SRE practice, including incident response and postmortems
• Break down pipeline problems into milestones and plans, and maintain architecture decisions, runbooks and API documentation

Required profile

• 7+ years of software engineering experience, including at least 3 years writing and operating high-performance Java in production
• Deep understanding of Java concurrency, parallelism and performance optimisation
• Hands-on experience with data processing pipelines on S3-compatible object storage and Linux system administration
• End-to-end delivery of production systems: code review, testing, monitoring, incident response
• Master's degree in Computer Science, Engineering or equivalent by experience
• Fluent English, autonomy and ability to explain technical trade-offs to non-engineers

Required skills

• High-performance concurrent Java
• S3-compatible object storage and streaming infrastructure
• Linux system administration
• Bonus: Kafka, Flink or Pulsar, time-series databases, renewable energy sector experience

What we offer

• Open to independent contractors (219 invoiced days per year) or payroll contracts; Belgian payroll includes home working 2 days per week, hospitalisation insurance, pension saving, representation allowance, meal vouchers, flexible income plan, 20 legal days off plus 12 compensation days, and transport/bike allowance
• On-the-job training, flexibility and an international environment with projects in over 100 countries