Software Engineer in Test

Senior C# Developer/SDET - £700pd (Inside IR35) - Hybrid (London) - Energy Trading

We are looking for a senior C# Developer/SDET to join a team building a new trading platform.

The team is developing a new end-to-end automated testing capability around the platform. Rather than simply writing tests against individual components, this person will be responsible for helping design and build a testing framework capable of simulating external dependencies and testing the application as a complete system.

A key part of the work will involve building simulators for external systems - for example, simulating an exchange receiving an order and returning fills - allowing realistic trading scenarios to be automatically executed and validated through the CI/CD pipeline.

This is a strongly development-led position rather than a conventional QA automation role.

Responsibilities

• Design and develop an end-to-end automated testing framework in C#.


• Build simulators/mocks for external systems and dependencies, including exchange-style interactions.


• Develop automated integration tests covering complete application workflows.


• Integrate the testing framework into automated build/deployment pipelines.


• Work with event-driven and live-data workflows.


• Build or contribute to backtesting/simulation capabilities.


• Understand the architecture of the trading platform and determine appropriate testing layers and strategies.


• Work closely with developers and trading/business users to reproduce realistic trading scenarios.

Key Requirements

• Strong software engineering fundamentals - this must be a developer-level coder.


• Experience building automated test frameworks rather than simply using existing testing tools.


• Strong integration and end-to-end testing experience.


• Experience building simulators, mocks or test harnesses for external systems.


• Experience with event-driven systems / live events.


• Experience integrating automated testing into CI/CD pipelines.


• Experience with backtesting, simulation or live-data testing would be highly desirable.


• Previous experience within electronic trading, energy trading, financial markets or another real-time/event-driven environment.


• Experience developing or testing trading platforms.


• Experience with BDD approaches/frameworks such as SpecFlow.


• Experience building exchange, market, execution or other external-system simulators.

Trading-domain experience is advantageous but not essential; candidates from other complex event-driven systems can be considered.

Commercials

• Contract position (Inside IR35)


• Initial contract through year-end, with good potential for extension


• Target rate around £700/day.


• Hybrid working - three days per week in the office (London)


• Immediate / ASAP start preferred.