Senior Non-Functional Test Engineer - Active SC Clearance - Inside IR35

Job Description We are seeking an experienced, highly skilled and 100% hands-on Senior Test Engineer to design, develop and implement advanced automated testing solutions for enterprise applications, digital services, REST APIs and complex microservices-based systems. The successful candidate must demonstrate strong technical expertise in API automation, UI automation, performance testing and non-functional testing, supported by strong programming skills in Java and/or TypeScript. This is a senior technical engineering role requiring the ability to independently design and develop automation frameworks, build and execute complex performance tests, analyse technical issues and contribute directly to software delivery. The role is primarily hands-on, rather than focused on test management, governance or strategy. Key Responsibilities Performance andamp; Non-Functional Testing - Critical Requirement Independently design, develop, configure, execute and analyse performance testing solutions using Apache JMeter, BlazeMeter, Gatling, k6 or equivalent tools. Build performance test scripts and test plans from scratch, including parameterisation, correlation, assertions and realistic workload modelling. Design and execute load, stress, spike, endurance/soak, scalability and capacity tests. Define realistic performance scenarios, concurrent-user models, workload profiles and performance acceptance criteria. Analyse response times, p95/p99 latency, throughput, concurrency, ..... full job details .....