Location: London/Hybrid (2-3 days on-site per week, remainder remote)Duration: 6 months + extensionClearance Requirement: Active SC (or SC-clearable with BPSS as a minimum)Rate: £500 per day (Inside IR35) SFIA 4 OverviewWe''re seeking an SC cleared Senior Data Engineer to design, build, and operate data solutions that power mission-critical analytics within a complex UK public-sector environment. You''ll lead on scalable, production-grade data pipelines on Microsoft Fabric (OneLake/Delta Lake, Data Factory, Synapse Data Engineering), using PySpark, Spark SQL, Python and SQL. You''ll help modernise Legacy estates, mentor other engineers, and turn raw data into reliable, secure, and actionable intelligence for high-stakes decision-makers.This role is aligned to SFIA Level 4 (Enable) - ideal for an engineer who is hands-on, collaborative, and comfortable shaping standards and delivery across multiple squads. What you''ll do Engineer production-grade data pipelines on Microsoft Fabric (OneLake/Delta Lake, Data Factory, Synapse Notebook Data Engineering) using PySpark/Spark SQL/Python and SQL, with a strong focus on: Performance andamp; scalability Resilience andamp; reliability Testing andamp; data quality Monitoring andamp; observability Support reporting andamp; MI use cases, delivering robust transformations and data models that feed downstream tools such as Power BI and other analytics platforms. Own CI/CD and DevOps practices: Build and maintain data pipeline CI/CD and