You will ensure the data we deliver to our clients is right. Sitting between data analysis and quality assurance, you will test the pipelines, data warehouses and lakehouse platforms that drive marketing, billing, credit and debt outcomes for clients across financial services, retail, energy, telecoms and media, water, and the not-for-profit sector. Working closely with our Data Engineers, Platform Engineer, UAT teams and client stakeholders, you will turn data mappings and specifications into test cases, reconcile data from source to target, investigate anything that doesn''t add up, and explain what you find clearly to both developers and clients. This is a hands-on, client-facing role for someone who enjoys getting stuck into the data. Key Responsibilities Write and run SQL to check, profile and reconcile data across source systems, staging, data warehouse and lakehouse layers Test ETL/ELT pipelines end to end, validating transformation logic, business rules and how data flows through each layer (bronze silver gold) Carry out data quality checks covering completeness, accuracy, duplicates, schema, referential integrity and row volumes Perform source-to-target reconciliation and migration parity checks, proving counts, totals and key-level data match the specification Write, run and maintain test plans and test cases from data mappings, specifications and acceptance criteria using Sagacity SPHERE''s YAML-driven test framework, keeping coverage current as new data sources ..... full job details .....