Principal Systems Engineer x 2 - Defence

Infinity Systems Engineering Ltd. is a Bristol based Systems and Safety Engineering Consultancy focused on the successful delivery of engineering projects in multiple sectors. We are a growing company at the forefront of cutting-edge defence engineering. We are hiring experienced Systems Engineers to deliver complex, safety-critical solutions across advanced weapon systems and aerospace platforms. Roles are available on a permanent basis, offering remote/hybrid and flexible working options. Usually once per week onsite in Bristol plus future client site meetings that are required depending on programmes.

Role Purpose

The Team Lead / Principal Systems Engineer will act as the primary interface between customer and the ISE Skilled Team, providing technical leadership, delivery governance, and workload management across all allocated activities. The role combines hands-on systems engineering capability with responsibility for task identification, scoping, prioritisation, resource allocation, quality assurance, and stakeholder engagement. You will ensure that the customer receives a responsive, coordinated engineering capability while maintaining visibility of progress, risks, capacity, and performance. There are four main domains to support:

• Deep Strike & Hypersonics
• Air Defence (surface-to-air)
• Air Dominance (air-to-air)
• Tactical Strike & Battlefield
• Future Combat Air System / Global Combat Air Programme

Key Responsibilities

• Act as the primary technical and delivery point of contact for customer stakeholders.
• Receive and triage new task requests from customer engineering teams.
• Work with customer stakeholders to understand objectives, constraints, timescales, and priorities.
• Scope and size activities, recommending appropriate delivery approaches and resource profiles.
• Allocate tasks across the Skilled Team based on complexity, priority, and capability requirements.
• Provide systems engineering leadership for complex or high-risk activities.
• Undertake technical reviews and approval of key deliverables.

Typical Activities

• Concept and feasibility studies.
• Requirements analysis and decomposition.
• System architecture development.
• Trade studies and option assessments.
• Bid and proposal support.
• Stakeholder engagement and technical workshops.
• Technical assurance and review activities.

Skills and Experience

Essential: Extensive Systems Engineering experience within Defence, Aerospace, Space, Rail, Nuclear, or similarly complex industries. Strong understanding of ISO 15288 Systems Engineering principles. Experience of early lifecycle engineering and concept development activities. Experience leading multidisciplinary engineering teams.

Desirable: MBSE experience (e.g. Enterprise Architect, Cameo, Rhapsody). Experience using DOORS or equivalent requirements tools.

Why Join Us?

Be part of projects that directly contribute to national security. Work with a high-calibre team of engineers across land, sea, air, and joint domains. Remote working available; however, for some roles, site/weekly visits as required in South West and South of UK.