Senior Engineer in London

The role involves working in one of our cross-functional, empowered engineering teams. Each team owns its part of the product and makes decisions jointly, alongside Product, Sales and other customer advocates. You will create new solutions to difficult problems and help take the platform to the next level. As a Senior Engineer, you will be a subject matter expert across multiple areas of the platform, involved in cross-team technical design, and independently responsible for the full lifecycle of the projects you deliver.

At this level, we expect your impact to reach beyond your own work: lifting your immediate team and raising the bar across engineering as a whole through technical leadership, reviews and mentoring. We also want you to help shape how we build. AI is already core to our product, and it is changing how we engineer software just as fast. We want someone with the curiosity and judgement to help us adopt it well, across how the whole team designs, builds, tests and ships.

Working with AI at Duco, we see AI as a genuine lever for how good teams build software, not a gimmick. We have made a strong start, with much more to build. A growing part of that is harness engineering: designing the environments, constraints and feedback loops that let AI coding agents work reliably at scale, so engineers shift from writing every line to designing the systems that govern how agents write code. It is a chance to apply what you know and keep learning as we build the future.

In this role you will:

• Use AI tools effectively in your own work, from writing and reviewing code to debugging and documentation.
• Help shape our pipelines and harness: guides, validation loops, test generation, CI/CD and quality gates that make AI‑assisted work reliable for the whole team.
• Bring ideas, and a healthy scepticism for hype, on where AI adds real value and where it does not.
• Champion safe, responsible use that respects code quality, security, data handling and our engineering standards.

You need not have done all of this before. Curiosity, judgement and a few real examples will go a long way.

Main areas of responsibility:

• Deliver features into the core product, across all areas of the technology stack.
• Own the full lifecycle of your work: design, development, deployment and ongoing support.
• Lead spikes and technical design for work that spans more than one team or domain.
• Code review your peers' contributions and give clear, constructive feedback.
• Tackle gnarly data manipulation and scaling problems with a team of very bright people.
• Mentor engineers and lift capability across the wider engineering function, including in how we use AI.

Requirements:

• Experience delivering and supporting resilient software that scales, in a multi-language, multi-technology stack.
• Deep experience with Java or another statically-typed language, and familiarity with a web framework (Spring Boot or Ruby on Rails).
• Strong skills in automated testing (unit, end-to-end, performance, stress) and a high bar for quality.
• Working knowledge of SQL and relational database concepts at scale, including performance optimisation.
• Technical or team leadership experience, with practical experience of service-oriented architectures and container-based deployment (e.g. Kubernetes, Helm).
• A genuine interest in using AI to improve software engineering, with ideas (and ideally hands‑on experience) for applying it individually and across a team's pipeline.

Beneficial:

• Aptitude with CI/CD pipelines (GitLab preferred) and cloud computing, preferably AWS.
• Experience with harness engineering or integrating AI / LLM-based tooling into a workflow or CI/CD pipeline, or with AI-assisted code review, test generation or developer productivity tooling.
• Experience of architectural migration (e.g. service extraction or refactoring) and feeding observability or metrics systems.

A market standard salary aligned with your skills and experience. Reviewed annually. Performance based bonus payments. Private medical insurance for employees. Healthcare cashback scheme and Death in service cover. Employee Assistance Programme, for extra support outside of work. Unlimited annual holiday, because we trust our people to manage their own time off. Opportunity to work abroad for up to 6 weeks per country per year. Enhanced family leave provisions. Personal learning and development opportunities (annual dedicated budget). Referral bonus if we hire someone great who you’ve recommended to us. An Employee Equity Purchase Scheme, so you have a personal investment in the success of the company. 4 Volunteering days off that can be used flexibly based on the employee’s choice of initiative. Salary Sacrifice Schemes - Cycle to Work, Tech Scheme, Electric Car Scheme.