Senior Software Engineer - Build Scalable, Trusted Systems

Parking; Watford; On-site; GBP 70,000 - 100,000; Full time

Job summary

CSL is seeking a Senior Software Engineer in Watford to own complex backlog tickets, deliver high-quality code, and uphold engineering standards. You will collaborate across the Signalling Engineering team, guiding design, testing and operations of software and tools.

You will mentor peers, participate in peer reviews, support roadmaps and ensure robust documentation and testing. The role emphasizes building scalable, maintainable solutions with measurable outcomes.

Qualifications

• Strong software engineering background for complex systems.
• Experience with testing frameworks and quality assurance.
• Ability to mentor engineers and influence stakeholders.
• Familiarity with pairing, code reviews, testing and continuous delivery.

Responsibilities

• Collaborate with Heads of Engineering and Architects to guide engineering.
• Provide technical knowledge and feedback through peer reviews.
• Support product roadmap and planning with engineering teams.
• Ensure documentation and testing are up to date.
• Lead troubleshooting and incident resolution across the product lifecycle.
• Ensure unit testing accompanies code and is fit for purpose.
• Evaluate new technologies through research and experimentation.

Skills

Software design

Code review

Test-driven development

Leadership

System design

Tools

Git

CI/CD

Monitoring tools

Job description

CSL is seeking a Senior Software Engineer in Watford to own complex backlog tickets, deliver high-quality code, and uphold engineering standards. You will collaborate across the Signalling Engineering team, guiding design, testing and operations of software and tools.

You will mentor peers, participate in peer reviews, support roadmaps and ensure robust documentation and testing. The role emphasizes building scalable, maintainable solutions with measurable outcomes.