Freelance System Engineer / Technical Architect

Role Details:

Level: Lead

Start Date: December

Duration: 6 months

Day Rate: Dependent on experience

Weekly hours: 5 days/ week

Location: Hybrid, 2 days a week in London

We're looking for a Systems Engineer / Technical Architect to help us reimagine a function of government as part of an agentic ecosystem.

You'll join a small multidisciplinary team of designers, researchers and engineers, working closely with civil servants and the department's own technical teams.
You'll own working out what the new system is. What are the constituent pieces, how do they fit together, and what’s needed to make it secure, accountable and auditable? The role suits someone who can sketch a target architecture on Monday and make it real with a prototype by Friday.

In this role you will:

• Design the target architecture based high-level requirements and constraints, agentic capabilities and best practices

• Recommend approaches to new challenges such as delegated authority and permissions

• Set out security, resilience and threat risks and mitigations, including agent-specific risks such as prompt injection and automated abuse

• Design and build the components that make the system accountable and auditable, such as audit logging and permission checks

• Identify and test the riskiest technical assumptions

• Build working prototypes and PoCs with the engineers

• Produce clear architecture decision records, diagrams and patterns that teams can reuse

• Engage with the client’s architects, security and assurance experts to get input and agreement on the right approach

• Set out a realistic path from prototype to delivery

Key skills and experience

Must haves:

• Significant experience as a technical or solution architect working on complex, ambiguous problems

• A strong background in API design, integration patterns and event-driven or distributed systems

• Deep knowledge of how agents interact with other parts of the system; tools, MCP servers, agent-to-agent protocols etc

• Experience designing for security, privacy, observability and auditability from the start including threat modelling

• Experience of authentication and authorisation, including delegated access, such as OAuth

• Hands-on coding skills, with the ability to build working prototypes quickly

• Cloud architecture experience (AWS, Azure or GCP) and infrastructure as code

• The ability to explain architecture clearly to designers, policy specialists and senior stakeholders

Nice to have:

• Experience in working on UK government services

• Exposure to data-sharing standards and legislation, such as the Digital Economy Act

• An agency or consultancy background

Location

You will need to be able to work from our offices (London) for a minimum of two days a week.

1. Application
Please attach your CV, plus a portfolio or any work you would like to also share.

2. Initial screening call
A short conversation to cover the basics — your timezone, working languages, availability, and a chance for you to ask early questions about the role and how we work.

3. Technical interview (~60 minutes)
A deeper conversation about your technical background and experience. We’ll talk through how you’ve approached real problems, the decisions you’ve made, and how you’d apply that thinking to the work at IF.

4. Ways of working interview (~45–60 minutes)
A conversation about how you collaborate, communicate, and work with others — including how you operate in an advisory capacity with clients and teams.

We’ll aim to keep you updated at every stage and let you know the outcome promptly after each step.