Lead Software Engineer - Umbraco

As Lead Engineer you will provide senior technical leadership on our Umbraco platforms, working alongside engineers, QA analysts and project managers to deliver high quality work on time and to budget.

We are looking for genuine Umbraco expertise rather than broad CMS familiarity: someone who knows the platform properly, has taken sites through major version upgrades, understands Umbraco Cloud and its constraints, and can make architectural decisions that hold up over the life of a long-term retainer.

You will join an existing Umbraco practice and work as part of a small group of technical leads, sharing responsibility for standards, architectural direction and the technical health of the platforms we look after. Our Umbraco clients are charities, non-profits and membership organisations, and the platforms we build for them carry donation journeys, supporter data and services people rely on. Much of the work is continuous improvement on established platforms rather than greenfield build, which means the technical decisions you make will be lived with for years by the teams that follow you.

You will lead architecture and technical planning on the projects you are responsible for, uphold quality through code review and standards, and develop the engineers around you. This role does not carry line management or resourcing responsibility, that sits with the Engineering Manager. Your focus is technical leadership and delivery quality., You provide senior technical leadership on the Umbraco platforms you are responsible for

• You are a senior technical authority on Umbraco, setting and upholding standards for how we build, extend and maintain client platforms.
• You make architectural decisions appropriate to the client’s budget, team and long-term maintenance capability, not to the most interesting technical option available.
• You plan and lead major Umbraco version upgrades, assessing package and integration compatibility before committing to a path.
• You maintain a clear view of the technical health of the platforms you support, and surface risk before it becomes a problem.
• You make sensible decisions about hosting, environments and deployment on Umbraco Cloud and equivalent platforms.
• You contribute to shared Umbraco standards and practice across the business, working with other technical leads rather than in isolation.

You define the technical approach for solutions and plan their delivery

• You consult with principal engineers and contribute to high level architecture during the Foundations phase of a project, specifying which technologies will be used and how they connect together.
• You provide broad plans for technical delivery, identifying the main themes, their approximate sizes, levels of risk and the order they will be delivered in.
• You produce estimates that state clearly what is in scope, what is out of scope and what assumptions the numbers rest on.
• You manage client expectations about the process of agile delivery and what they should expect to see at the end of each sprint.

You lead the delivery of high quality software on time and to budget

• You ensure your project team members are fully engaged and participating in all aspects of the project during evolutionary development.
• You ensure the ceremonies of your agile project happen at the right time with the right people present, including stand-ups, backlog refinement, timebox planning, code reviews and retrospectives.
• You ensure your team delivers the work they have committed to by the agreed deadline.
• You uphold quality through code review, and hold the line on standards when delivery pressure argues against it.
• You apply particular rigour to anything touching donation journeys, payment integrations or supporter data, where the cost of a defect is measured in lost income and lost trust.
• You ensure your team collaborates well at all times, that problems are discussed early and raised to the project lead and client as necessary.

You manage the technical and support relationships with your clients

• You are the senior technical point of contact for the clients you support, able to explain technical decisions and constraints to non-technical stakeholders clearly.
• You lead the technical response when things go wrong on your accounts, establishing what has happened and directing the fix.
• You ensure your clients are supported by the appropriate team members, working with engineering managers so the right profile of engineer is available.
• You ensure the smooth operation of support boards, unblocking technical team members and resolving issues.
• You provide the technical continuity that long-term retainer clients depend on, holding the context that would otherwise be lost between people.

You support the growth of the engineering team and promote quality software engineering

• You develop the engineers around you, particularly those growing their Umbraco capability, through pairing, review and structured mentorship.
• You show passion for keeping on top of current tools, standards and trends, including the Umbraco roadmap and AI-assisted engineering practice.
• You actively contribute ideas for the growth of the engineering team.
• You collaborate with principal engineers and the engineering leadership to deliver on departmental goals.
• You produce relevant content on software engineering and agile delivery to raise the profile of the department., * You are someone the team turns to on Umbraco questions, and you answer in a way that leaves them more capable rather than more dependent.
• You manage challenging situations effectively and defuse issues before they escalate.
• You guide and support other team members, particularly those less experienced, and are helpful in onboarding new starters.
• You proactively seek and give timely, actionable feedback that improves the contribution of those around you.
• You escalate problems that have a wider scope than your team, and support them through to a conclusion.
• You work confidently and persist when faced with uncertainty, pulling in support from around the company where needed.
• You promote good practice and current trends in your discipline, deepening the knowledge of those around you.
• You lead teams and clients confidently and hold relationships with important stakeholders.
• You influence the strategic direction of projects and are comfortable on large, complex work.
• You are a trusted problem solver, capable of leading the resolution of incidents relating to your area of expertise.
• You hold the line on quality when delivery pressure argues against it, and can explain why in terms a client understands.
• You support our inclusive environment and ESG commitments, and embody Manifesto’s values.

Professional knowledge and experience

• Deep Umbraco expertise. Extensive hands-on experience building, extending and maintaining Umbraco platforms in production, including recent major versions. This is the defining requirement of the role.
• Strong .NET and C# capability.Confident writing clean, maintainable, object-oriented code and reviewing the work of others to the same standard.
• Upgrade and migration experience. Proven experience planning and delivering major Umbraco version upgrades, including assessing package compatibility and managing risk on live sites.
• Long-term platform ownership. Experience maintaining and evolving established platforms over years rather than delivering and moving on, with an understanding of how technical debt accumulates and how to manage it down.
• Integrations and APIs. Proficiency designing and implementing APIs and integrations within complex digital ecosystems, including CRM, payment and marketing platforms.
• Database and data management. Strong expertise in database design and efficient querying in the context of web applications.
• Cloud and deployment. Practical experience with cloud platforms and managed hosting, particularly Azure and Umbraco Cloud, and with CI/CD pipelines and environment management.
• Front-end capability. Adept at building responsive, accessible interfaces, with a component-based approach that supports consistency and reuse.
• Accessibility.Deep commitment to and experience of building to WCAG standards, which matters particularly for the diverse audiences our charity clients serve.
• Security. Proven ability to apply security best practice throughout the development lifecycle, safeguarding supporter and donor data.
• Technical leadership.Proven leadership in agile delivery, with a focus on quality outcomes and collaborative teams. Excels at mentorship and technical direction without line management responsibility.
• Client-facing confidence. Exceptional problem solving and the ability to manage technical client relationships directly.

Technical skills

Essential

• Deep, demonstrable Umbraco expertise across recent major versions, including content modelling, custom development and package ecosystem
• Strong .NET and C#, with a solid grasp of modern .NET practice
• Umbraco Cloud, or equivalent managed hosting experience, including environment strategy and deployment workflow
• Major version upgrade planning and delivery on live platforms
• API design and consumption, REST and GraphQL, including third-party integrations
• SQL Server and efficient data querying in a web application context
• Modern front-end development, including component-based approaches and responsive UI
• Accessibility standards and practice, WCAG 2.2 and above
• Security by design, particularly around personal data and payment journeys
• Git, branching strategy, code review and CI/CD pipelines

Desirable

• Azure services, particularly Functions, App Services and supporting infrastructure
• Headless or decoupled Umbraco, and API-first delivery
• Modern front-end frameworks such as React or Next.js
• Experience with donation or payment platforms
• Working knowledge of other CMS platforms, particularly Drupal and Wordpress
• AI-assisted engineering practice or agentic tooling
• Experience in the charity, non-profit or membership sector

manifesto

We are the digital experience agency for changemakers. We are committed to delivering purposeful and positive impact for people, planet and society, in restless pursuit of a better world.

We take pride in creating award-winning digital experiences, products and services that are measurably ethical, inclusive, accessible, sustainable and joyful.

Our changemaker clients include UNICEF UK, Breast Cancer Now, Trussell, Woodgreen, The Royal Academy of Arts, Zoological Society London, Historic Environment Scotland and Fauna & Flora.

Part of the TPXimpact group - a Certified B Corporation , we are a team of 130 digital product leaders, creative designers, user experience designers, engagement specialists, software engineers and experience strategists. TPXimpact

TPXimpact is a digital transformation company, and Certified B Corporation , on a mission to build a future where people, places and the planet are supported to thrive. Combining vast expertise in human-centred design, data, experience and technology, we help the public, private and third sectors with their digital transformation journey, delivering high quality solutions that improve services, experiences and outcomes. We’re passionate people who work in close collaboration with our clients to create sustainable solutions ready for an ever-evolving world.

We are committed to having a positive impact on the clients and the communities we serve. We actively encourage applications from all genders, ethnicities, disabled people, members of the LGBTQIA+ community, and those from lower socio-economic backgrounds.

Don’t meet 100% of the criteria? We still want to hear from you. Please let us know if you require any adjustments during the recruitment process.