Lead Software Developer

Job summary

If you’re interested in making a difference to people’s lives, the Treasury can offer you an exciting opportunity to influence decision making that affects the whole of the UK. Working at the heart of government, we collaborate across government to promote responsible public spending and drive strong and sustainable economic growth.

Our work ranges from protecting customers through the regulation of the financial sector, helping to reduce carbon emissions and creating a greener economy, to promoting British trade around the world and supporting people across the country on jobs, growth and more.

We are part of the Darlington Economic Campus, a cross-government hub bringing people together to tackle key national issues while working closer to the communities we serve.

Job description

As a Lead Software Developer, you will build modern software applications that enable excellent use of data and information at the heart of some of HM Treasury's most important business processes - directly supporting work that shapes public spending decisions and economic and fiscal policy making.

You will lead the design, development and continuous improvement of digital products used across HM Treasury and wider government. Working with both front-end and back-end technologies, you will create secure, scalable and user-centred applications that solve real user problems and deliver tangible business value.

You will also play a key role in promoting excellent software development practices across the Data Hub and wider HM Treasury Coding Community. You will work closely with Data Scientists and Data Engineers in the Data Hub and provide technical leadership, support capability development and help foster a culture of software engineering excellence across the department.

Key Accountabilities

1. Back-End Application Development and Service Ownership: You will design, develop and maintain secure, scalable and resilient back-end services using Python frameworks (e.g. Flask), Azure cloud services and related technologies. You will ensure applications and services operate reliably in production, proactively monitoring performance, responding to issues and continuously improving service quality and availability.
   
   
2. Front-End Application Development: You will lead the design and development of accessible, intuitive and user-centred front-end applications that meet the needs of users, using Python-based front-end frameworks (e.g. Plotly Dash) and JavaScript frameworks (e.g. React) as appropriate.
   
   
3. Solution Architecture and Systems Integration: You will design and assure scalable software architectures that meet business and user needs. You will evaluate and select appropriate technologies, design patterns and development approaches, ensuring effective integration between applications, data platforms, APIs and enterprise services across HM Treasury and, where required, wider government.
   
   
4. User Engagement and Agile Product Development: You will engage extensively with users throughout the software development lifecycle, conducting discovery activities, gathering requirements, validating assumptions and facilitating testing. You will apply user-centred design principles to ensure products are driven by user needs and deliver measurable value to the organisation.
   
   
5. Technical Leadership and Delivery: You will provide technical leadership across software development projects, maintaining responsibility for technical quality throughout the software lifecycle. You will guide development teams in adopting modern engineering practices, manage technical risks and dependencies, and support successful delivery using agile and iterative approaches.
   
   
6. Security, Standards and Engineering Excellence: You will ensure that software, services and platforms are designed with appropriate security controls, operational monitoring and governance from the outset.
   
   
7. Innovation and Emerging Technologies: You will identify opportunities to use innovative technologies, including generative AI and other emerging capabilities, to improve business processes, enhance user experiences and increase organisational effectiveness. You will support the safe, responsible and effective adoption of new technologies across HM Treasury.
   
   
8. Software Development Champion: You will help develop engineering capability across the team and organisation, and advocate for the adoption of good software engineering practice.

Candidate Drop-In Session

The hiring manager will be running a candidate drop-in session to give you greater insight into the role and HM Treasury, and to answer any questions you may have.

If you would like to join, please use the Microsoft Teams link below at the scheduled time:

Date & Time: Wednesday 29th July 2026, 17:00–17:45

Join the meeting: https://teams.microsoft.com/meet/323951144201999?p=AciR6lipMUjiOXRb4p

Meeting ID: 323 951 144 201 999
Passcode: rP9CD7rH

If you would like to speak to the hiring manager informally prior to the closing date, please contact Laurie McClymont at [email removed]

Visa sponsorship is not available for this role.

Person specification

Application Stage

Applications should consist of a 1,000-word personal statement setting out how you meet the shortlisting criteria below and a CV including your employment history. Your CV and employment history won’t be scored. It’s used to give context to your application and support discussions at interview.

The panel will review applications and invite those that best demonstrate evidence of the shortlisting criteria for interview. Please keep this in mind when writing your application.

If you are interested but feel you don't yet meet every requirement, please apply. We value enthusiasm, aptitude for growth, and diversity of thought and experience, alongside the criteria outlined.

Please note that only applications submitted through Civil Service Jobs will be accepted.

Criteria (application stage)

1. Programming and Build in Software Engineering: Demonstrate strong hands-on experience building and supporting software applications across both front-end and back-end technologies, including Python frameworks, using modern software engineering practices.
   
   
2. Systems Design: Demonstrate experience designing secure, scalable and maintainable solutions using cloud technologies. We have a preference for Azure, but experience across Google or Amazon cloud services are welcome.
   
   
3. User Focus & Agile Product Delivery:Demonstrate experience delivering digital products using Agile methodologies that genuinely meet user needs, including direct stakeholder engagement, iterating on feedback and working within multidisciplinary teams to drive continuous improvement.
   
   
4. Technical Leadership & Engineering Culture: Demonstrate experience providing technical leadership, mentoring team members and actively promoting good software engineering practices across a team or organisation.

Interview Stage

If you are successful at the application stage, you will be invited to interview where you will be assessed against the fol