Test Engineer

We have a great opportunity for an experienced test engineer to join our excellent software development team based in Cambridge. This is an ideal role for someone who wants to join a friendly, small and highly technical team where you can have a real impact.

Apply with your CV and covering letter


We have a great opportunity for an experienced test engineer to join our excellent software development team based in Cambridge.


GMSL is the market-leading provider of 24/7 energy portfolio management services and software in Europe and plays a vital role in the energy business. We have unparalleled expertise in the industry, built up over 25 years of operating in energy markets throughout Europe.

Our software is used by some of the largest energy companies in the world and is developed using our unique operations experience, giving us clear insight into our customers’ needs. For more background on GMSL see https://www.gmsl.co.uk

Development approach

We develop software using an agile approach, which focuses on our ability to respond to change. Our culture is broadly based on Extreme Programming (XP) practices, but we take a pretty pragmatic view about this. We adapt our processes to support the context, rather than follow a standard rigid process for all situations.

Product teams

We develop software in a number of small product teams, each focused on one of our software products. Testers are an integral part of our product teams working alongside developers and business experts in every stage of the software development process. Our work is very collaborative, and having a friendly office environment is very important to us.

We trust the teams who do the work to learn how best to do it.

Testing approach

Our testers follow a context-driven testing approach, treating learning, test design and test execution as simultaneous tasks. We understand our customers’ needs and help ensure the team are solving the right problems to deliver value to our users. We adapt our testing process according to the needs of the product, the team and the goals of the current development. Testing for us includes exploratory testing, creating automated tests, and creating our own test tools and scripts, depending on the type of risks we identify.

Training and development

We encourage learning for all and provide time for people to improve on their skills and learn new ones. We provide access to online training courses, pro membership to Ministry of Testing, and also attend training courses, such as Rapid Software Testing. We also run regular internal knowledge sharing sessions and attend conferences and local meetups.


Once you have gained an understanding of the messaging systems, communication services, and APIs under development, the role will include the following responsibilities:

  • Clarifying requirements and challenging assumptions during the development of new features.
  • Identifying areas of risk where testing would add value.
  • Exploratory testing of complex and wide-ranging services and APIs.
  • Helping to recreate and troubleshoot issues.
  • Acceptance testing in collaboration with the Product Owners.

Your experience

We are looking for someone who:

  • Has 5+ years’ experience in software development as a software tester or engineer, or similar role.
  • Has demonstrable experience of end-to-end testing of complicated, distributed systems.
  • Has good experience of functional, performance, and load testing of services and APIs.
  • Is comfortable interacting with cloud services as a part of testing.
  • Has a technical and inquiring mind, and enjoys problem solving and lateral thinking.
  • Has good interpersonal skills and enjoys collaborating with others. Everything we do is done as part of a team, so being able to cooperate with others to meet shared goals, empathise, and form trusting relationships is key.

It would be beneficial, but not essential, to have experience of some of the following:

  • Monitoring, analysis and troubleshooting (on-prem and cloud)
  • Source control, task management
  • Understanding of FTP, FTPS, SFTP, IMAP, POP protocols
  • Understanding of public/private keys for secure communication
  • Some ability to read code
  • Understanding of web auth mechanisms
  • Use of mocked services and in-house tools for testing
  • Maintaining test environments
  • Automation and scripting
  • Network inspection

Some of the tools we use include the following. You don’t need any experience of these, but you can expect to be using them in the role:

  • Postman, Insomnia
  • JMeter
  • Resource Monitor, Computer management, Event Viewer, Certificate Manager, Regedit
  • Prometheus, Grafana
  • SQL Server, MSMQ
  • AWS CLI, CloudWatch, S3, DynamoDB, ECS monitoring, API gateway, Lambda, SQS, Code Pipeline
  • GitHub
  • FileZilla, ProFTPD, Dovecot? POP3?
  • OpenSSL
  • JSON Web Tokens
  • Linux OS (Debian), Windows Server Core
  • PowerShell, CMD, Visual Studio
  • Wireshark, TCPView

All our software teams spend at least one day a week in our office and this role requires 2-3 days a week in our office, so you need to be based within easy travel to Cambridge.


Salary will be reflective of your level of experience.

  • Location               Central Cambridge – Hybrid (2-3 days a week in office)
  • Job type               Permanent
  • Hours                   Mon-Fri, 37.5 hours per week


Our benefits include:

  • Annual discretionary bonus scheme
  • Company pension scheme (6% employer contribution)
  • 25 days’ holiday
  • Private health care
  • Flexible working hours and remote working
  • Casual dress and a relaxed environment
  • Employee assistance program
  • Loyal service award
  • Cycle to Work scheme
  • Fresh fruit and great coffee
  • Free access to Cambridge University Botanic Gardens
  • Monthly team pub lunches

Working at GMSL

We are a small team. We have around 30 people in our software team, so even though we are a part of a company of around 100 people overall, the software team has retained a small team “startup” feel. Your colleagues will be from a wide variety of backgrounds – we encourage diversity, openness and gender equality.

We value the long-term. The success and stability that comes from 25+ years’ experience in software development means we value the long-term in terms of software development and the development of our people.

We empower teams and individuals. Teams are empowered to own their products. Individuals are empowered to make meaningful contributions at every level.

We are agile. We develop using an agile approach, which focuses on our ability to respond to change. We adapt our processes to support the context, rather than follow a standard rigid process for all situations. We trust the teams who do the work to learn how best to do it.

We strive to make GMSL a great place to work. The management team are friendly, approachable and care personally about the people on their team. Managers consider the people on their team as the first priority and take our people’s personal situations into account in decision-making wherever they can.

We are flexible. Our software teams typically work at least one day a week in our office in Cambridge, and the rest of the time working flexibly, dependent upon the role. We also have a day a month where the whole software department comes in and we all go to the pub for lunch. Hours are flexible and are based on the needs of the team.

How to apply

Simply email us your CV and covering letter to recruit@gmsl.co.uk.

We will only consider people with a valid UK work permit.

GMSL have a responsibility to ensure that all employees are eligible to live and work in the UK, proof of right to work in the UK will be requested prior to employment.

Recruitment Agencies

We are not currently accepting recruitment agency applications, we’ll be in touch if we need you to help us. Thanks for your understanding.

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