C# Developer In Test

October 25, 2026

Senior

London, England, United Kingdom

Description

Join a product engineering team where quality is built into development rather than added at the end. Developers in Test automate test cases using the same languages and standards as the developers, combining automation with technical and exploratory testing. Alongside coding and analyzing the root causes of defects, you’ll help develop CI/CD pipelines and take part in architectural discussions. This is a full-time, office-based role in London, England, United Kingdom.

Responsibilities

Automate test cases using the same languages and standards as the team’s developers
Spend most of your day coding, keeping manual testing to a minimum
Create fast, reliable automated tests and investigate test failures
Improve automation efficiency using modern tools and framework techniques
Use AI assistants to speed up test script generation and improve code quality
Improve existing CI/CD pipelines or build new ones
Mentor other QA engineers on automation best practices
Proactively help complete automation tasks from the backlog
Perform in-depth root cause analysis of defects and, when needed, investigate the source code directly
Take part in software architecture discussions and interactive whiteboard sessions
Work with the team on user stories and acceptance criteria
Become a product expert and the go-to person for product knowledge across the business
Take part in regular knowledge-sharing sessions with the engineering team
Teach colleagues how to write better code

Requirements

3+ years of hands-on experience with C#, including writing unit and integration tests
Experience with mocking frameworks
Strong experience developing, maintaining, and scaling test automation frameworks
At least 2+ years of focused API testing experience
Experience with Docker
Willingness to build and optimize CI/CD pipelines
Familiarity with or a strong interest in AI development tools (GitHub Copilot, ChatGPT, and similar tools)
Understanding of testing concepts, methodologies, and processes
Basic understanding of web technologies, including web services, application servers, and RESTful APIs
Strong analytical and problem-solving skills, with a curious mindset
Willingness to take part in and often lead technical discussions
Ability to learn quickly and tackle complex, fast-changing challenges
Collaborative approach and ability to work with a range of stakeholders
Proactive approach to personal development and accountability for results
Passion for software quality and customer experience

Conditions

Full-time employment
Office location: London, England, United Kingdom
A working approach that combines automation with technical and exploratory testing
The company provides accommodations for candidates and employees who need them
A collaborative working environment where all employees are treated equally
Significant investment in both business growth and employee development