Role: Performance Tester Work Model and Location: Hybrid - 2-3 day onsite in Reading Duration: 6 Months+ The role involves validating system scalability, response time, throughput, and stability under real-world and peak load conditions to ensure business-critical billing processes operate without performance degradation. Our client, working with a British multinational energy company who are a constituent of the FTSE 100 Index are seeking an experienced Performance Tester to support the Keystone transformation program, focusing on non-functional validation of billing systems, integrations, and dual run operations. Your responsibilities: Analyse performance testing requirements including user load, throughput, transaction volumes, and usage patterns Prepare Performance Test Strategy and Test Plan aligned to program milestones Design and develop performance test scripts using JMeter and/or LoadRunner Execute load, stress, endurance, and volume testing Monitor application performance using tools such as Dynatrace, AppDynamics, or Azure Monitor Analyse results and identify bottlenecks and system limitations Prepare performance reports and tuning recommendations Manage performance defects through to resolution Support dual run validation ensuring stable billing operations Validate high-volume transactions across multiple integrated systems. Your Profile Essential skills/knowledge/experience: 5 10 years of experience in Performance Testing / Non-functional Testing ..... full job details .....