Integration and System Test Engineer in Dunstable

SII Group delivers Digital Services, IT, Engineering, and Consulting to diverse industries, enabling digital transformation through our commitment to Growth, People, and CSR. With over 16,000 professionals across 21 countries, we’re recognised as a “Great Place to Work” for fostering a high-trust culture. Our core values of Trust, Transparency, and Quality drive our work package delivery, ensuring we meet and exceed client expectations as a committed partner.

The Opportunity

SII is supporting the delivery of a high-profile, high-security UK national infrastructure programme. We are seeking an experienced Integration & System Test Engineer to play a key role across Integration, System Integration Testing (SIT1 & SIT2), and customer acceptance activities. This role offers the opportunity to work across the full system test lifecycle, collaborating closely with IVVQ, development, and customer stakeholders to ensure a robust, secure, and fully validated solution. You will be central to assuring system quality from development through to pre-production, production, and Site Acceptance Testing (SAT).

Key Responsibilities

• Plan, develop, execute, and report Integration, SIT1, and SIT2 test activities across the programme.
• Support internal system validation and external customer acceptance throughout the development lifecycle.
• Develop and maintain test strategies, plans, specifications, and test descriptions aligned with system requirements.
• Execute functional and non-functional testing, including performance, robustness, and end-to-end verification.
• Prepare and manage test data required for integration and system testing.
• Ensure full requirements traceability and coverage across all test phases.
• Track, triage, and support resolution of defects, working closely with development teams.
• Support Authority-led Site Acceptance Testing (SAT) and readiness for pre-production and production deployments.
• Produce formal test reports and evidence, securing internal approval prior to customer submission.
• Report progress, risks, and test outcomes to the IVVQ Manager and project stakeholders, proposing mitigation actions where required.
• Operate within UK government frameworks, supporting the delivery of secure, regulated systems.

Essential Skills & Experience

• Proven experience delivering integration and system testing on complex systems.
• Strong background in SIT1 / SIT2 planning and execution.
• Experience producing and managing test documentation (plans, cases, specifications, reports).
• Solid understanding of requirements traceability and test coverage.
• Experience managing defects and test findings in collaboration with development teams.
• Ability to work effectively with multiple stakeholders in structured delivery environments.
• Experience operating in high-security or regulated environments (e.g. government, defence, critical infrastructure).
• Work on site minimum 4 days per week and be able to obtain SC clearance.

Desirable Skills

• Experience supporting or witnessing customer or Authority-led acceptance testing (SAT).
• Familiarity with IVVQ frameworks and structured V-model delivery.
• Experience working across pre-production and production readiness activities.
• Previous involvement in national infrastructure or border / identity systems.
• Comfort working across on-site and secure remote environments.
• Hold valid SC clearance.

Benefits

• Competitive Basic Salary.
• 6% Employers Contribution + 6% as a salary sacrifice.
• Private Medical Insurance, Life Cover and Income Protection.
• 25 days holiday.
• 10 days full sick pay per year.
• Flexible working.
• Cycle to Work & TechScheme.
• Continuous professional development.
• Corporate access to the Udemy platform.

If you’re applying for a role requiring security clearance, please be aware that foreign or dual nationality is not an automatic bar, however certain posts may have restrictions which could affect those who do not have sole British nationality or who have personal connections with certain countries outside the UK.