Non Functional Tester

The Non-Functional Tester is responsible for validating the performance, scalability, reliability, and accessibility of enterprise applications. The role designs and executes non-functional test strategies, analyses results, and partners with engineering and business stakeholders to ensure systems meet defined non-functional requirements (NFRs).

Key Responsibilities

  • Understand Non-Functional Requirements (NFRs) and scope from client documentation
  • Develop and maintain non-functional test strategies and plans aligned with business and technical objectives
  • Design and execute performance tests using tools such as JMeter, Azure Load test to evaluate system scalability and reliability, reporting using Blaze meter
  • Perform accessibility testing using Wave, Axe to ensure compliance with WCAG and other accessibility guidelines
  • Analyse test results to identify trends, patterns, and areas for improvement in system performance
  • Prepare detailed test reports, including metrics such as response times, throughput, and defect summaries
  • Collaborate with developers, architects, and business analysts to resolve non-functional issues and optimize system performance
  • Conduct load, stress, soak, and spike testing to validate system behaviour under varying conditions
  • Integrate non-functional tests into CI/CD pipelines to enable continuous performance validation
  • Define non-functional acceptance criteria and service-level objectives (SLOs) in collaboration with stakeholders

Required Skills

  • Should have experience in non-functional / performance testing of enterprise web and API-based applications
  • Hands-on expertise with performance testing tools such as Apache JMeter and Azure Load Testing, with result analysis and reporting in BlazeMeter
  • Experience with accessibility testing tools such as WAVE and Axe, and a working knowledge of WCAG 2.1/2.2 compliance standards
  • Strong understanding of non-functional requirements including performance, scalability, reliability, availability, and security
  • Ability to analyse performance metrics (response time, throughput, latency, resource utilisation) and identify bottlenecks
  • Familiarity with APM and monitoring tools (e.g., Dynatrace, AppDynamics, Grafana) for system observability
  • Experience integrating performance tests into CI/CD pipelines (e.g., Azure DevOps, Jenkins, GitLab).
  • Working knowledge of cloud platforms (Azure / AWS) and containerised environment

Job Details

Company
Cognizant
Location
London Area, United Kingdom
Posted