Senior Test Automation Engineer

Expleo is seeking an experienced Senior Test Automation Engineer to join our Digital Assurance practice, supporting a key client within the energy trading sector. This role will be responsible for defining and implementing robust test automation solutions, ensuring the quality, reliability and performance of business-critical applications and data platforms. The successful candidate will combine strong automation engineering capabilities with excellent analytical skills to deliver high-quality testing solutions across complex systems, data integrations and event-driven architectures. Responsibilities Define test strategies, coverage models and acceptance criteria from functional and non-functional requirements. Design, develop and maintain automated test frameworks and regression test suites. Develop test automation solutions using C# and BDD methodologies. Create and maintain robust Gherkin scenarios and step definitions. Determine the optimal balance between manual and automated testing, typically operating within a 70:30 automation-to-manual testing approach. Integrate automated tests into CI/CD pipelines and development workflows. Perform testing of large datasets, data flows and data mappings. Execute test cases, analyse results and clearly communicate defects, issues and risks. Utilise approved AI-assisted tools to support test design, exploratory testing, automation development, analysis and reporting. Critically review and validate AI-generated outputs to ensure adherence to quality, security and development standards. Collaborate closely with developers, analysts and business stakeholders within Agile delivery teams. Drive continuous improvement initiatives while adhering to the client's development lifecycle and quality standards. Essential Skills Programming & Platforms C# .NET ASP.NET Core SQL JSON XML Testing & Automation Reqnroll / SpecFlow Microsoft Playwright WireMock Postman Newman Bruno CLI Development & Delivery Visual Studio Git Azure DevOps Repositories Azure DevOps YAML Pipelines Event Streaming & Messaging Apache Kafka (Aiven) Schema Registry Avro JSON Messaging RabbitMQ Data & Observability Microsoft SQL Server OpenTelemetry ClickStack / HyperDX ClickHouse ELK Stack (Elasticsearch, Logstash, Kibana) Desired Skills Excellent analytical and problem-solving capabilities. Strong stakeholder communication and collaboration skills. Familiarity with Azure DevOps, TFS, Jira or similar Application Lifecycle Management tools. Exposure to observability and monitoring platforms. Knowledge of event-driven and microservices architectures. Experience Proven experience in test automation engineering within Agile environments. Strong experience in C# test automation development. Experience creating and maintaining BDD frameworks and behaviour-driven test suites. Demonstrable experience building automated regression test packs and integrating them into CI/CD pipelines. Strong SQL skills with experience validating complex data structures and integrations. Experience testing APIs, event-driven systems and distributed architectures. Experience using AI-assisted engineering and testing tools. Experience within energy, utilities or trading environments. Experience working within regulated enterprise environments. Benefits Collaborative working environment – we stand shoulder to shoulder with our clients and our peers through good times and challenges  We empower all passionate technology loving professionals by allowing them to expand their skills and take part in inspiring projects   Expleo Academy - enables you to acquire and develop the right skills by delivering a suite of accredited training courses  Competitive company benefits Always working as one team, our people are not afraid to think big and challenge the status quo  As a Disability Confident Committed Employer we have committed to: Ensure our recruitment process is inclusive and accessible Communicating and promoting vacancies Offering an interview to disabled people who meet the minimum criteria for the job Anticipating and providing reasonable adjustments as required Supporting any existing employee who acquires a disability or long term health condition, enabling them to stay in work at least one activity that will make a difference for disabled people “We are an equal opportunities employer and welcome applications from all suitably qualified persons regardless of their race, sex, disability, religion/belief, sexual orientation or age”. We treat everyone fairly and equitably across the organisation, including providing any additional support and adjustments needed for everyone to thrive