Performance Tester - Permanent

AgileSource are looking for 4 - 5 Senior Performance Testers on a Permanent basis. This role will require 1 day a week in the office (London or Newcastle).

Role Summary

An experienced Performance Test Specialist is required to plan and deliver performance validation activities across complex digital platforms and core Back End systems. The role focuses on practical implementation within structured delivery environments where system stability, throughput, and scalability are essential.

This position is delivery-oriented and requires strong technical capability in modern cloud-based and distributed architectures.

Core Responsibilities

• Develop and implement performance test strategies including load, stress, endurance, capacity, and scalability testing

• Evaluate test outcomes, application logs, and infrastructure metrics to identify performance constraints

• Define and confirm non-functional performance requirements, workload models, and capacity estimates

• Create and maintain automated performance scripts and supporting documentation

• Conduct testing within cloud-hosted non-production environments

• Document and report performance issues with supporting technical evidence

• Integrate performance testing activities within automated build and deployment pipelines where applicable

• Produce performance reports and contribute to defect review discussions

• Collaborate with engineering, architecture, infrastructure, and operations stakeholders

Required Experience & Skills

• Demonstrated experience delivering performance testing for large-scale enterprise solutions

• Practical expertise with industry-standard performance tools (eg, JMeter, Gatling, LoadRunner, k6, or comparable platforms)

• Strong understanding of:

  • API-driven services and HTTP protocols

  • Database and data-layer performance considerations

  • Messaging systems and caching mechanisms

  • Distributed system behaviours under load

• Experience interpreting system logs, monitoring dashboards, and performance metrics

• Exposure to Agile or blended delivery methodologies

• Experience working within controlled, compliance-driven, or assurance-focused environments

Advantageous Experience

• Familiarity with application performance monitoring and observability platforms (eg, Dynatrace, AppDynamics, Elastic stack, Grafana)

• Experience contributing to large, multi-team programmes

• Knowledge of digital service standards or structured governance frameworks

Accountability & Scope

• Responsible for designing and executing assigned performance testing activities

• Ensures quality and accuracy of produced test artefacts and analysis

• Provides findings and recommendations while operating under senior test leadership

• Delivers agreed performance testing outputs within defined timelines