Data Engineer

Location: London Contract: Interim / Long-term project Sector: Secure Banking & Payments Pay: £550 - £650 per day Are you a Data Engineer who thrives in large-scale, mission-critical environments? We’re supporting a major banking programme delivering a high-stakes data migration within payments—an environment where precision, stability and performance genuinely matter. This is an opportunity to take ownership of complex extraction and migration activity in a live payments landscape, ensuring data integrity, zero disruption to BAU and a smooth transition for one of the UK’s most trusted financial institutions. What You'll Be Doing Leading high-risk, high-volume data migration in a banking environment, with a focus on payments and critical transaction platforms. Responsibilities include: Core Engineering Work • Designing and delivering safe, controlled data extraction strategies from heavily-used production environments. • Mapping, tracing and reconciling data across legacy and target systems. • Validating migrated datasets to ensure accuracy, completeness and regulatory fit. • Running ETL processes within tightly-governed production frameworks. Technical Environment A key element of this role is deep hands-on expertise with IBM DB2 on Mainframe, including: • Indexing, clustering and partitioning • Performance tuning and query optimisation • Understanding how to operate within congested, high-throughput table structures Exposure to Oracle is beneficial for adjacent extractions across the wider programme. What Makes You a Strong Fit We’re looking for someone who demonstrates: • High-scale systems experience where extraction must not impact live processing. • Confidence working independently in ambiguous situations. • Proactive identification of risks or production concerns. • Clear, early communication when issues arise. Experience in retail banking payments, or in similarly high-risk, high-volume environments such as capital markets or trading platforms, is highly valuable. Why Join This Programme? • Work on a major payments transformation with real business impact. • Play a pivotal role in risk-free migration of critical data. • Join a collaborative, secure, engineering-led environment. • Begin with interim discovery and mapping work, with scope to expand as senior resources onboard. If you’re a Data Engineer who enjoys complexity, thrives under pressure, and delivers clean, reliable outcomes in critical environments, we’d love to hear from you.