Senior Product Engineer in London

Basis: Full-time, permanent

Location: Canary Wharf, London - WeWork (Hybrid Remote)

Reporting to: Director of Product Engineering

Great products start with great people. Our relentless focus on user experience has been the cornerstone of our growth, helping us become the market leading software for fire protection subcontractors across the UK. We’ve grown by staying obsessed with building software that actually works for the subcontractors on the ground; fast, intuitive, and simple to use. We’re now gearing up for our next chapter: expanding into new trades and taking Onetrace global. We’re bootstrapped, profitable, and driven by a clear mission - to lead the digital transformation for subcontractors, one trade at a time.

Come be part of a team that’s smart, ambitious, and comfortable in the chaos of growth - where your ideas matter, and your work shapes what comes next. We’re not your typical "move fast and break things" company. We believe in building thoughtfully and shipping quality software that genuinely helps our customers solve real problems.

Working here means being a product engineer, not just a backend or frontend specialist. We care about engineers who understand the bigger picture: the operatives on site, the project teams behind them, and the real-world impact of the tools we ship. You’ll bring curiosity to the "why" behind the work, not just the "how," and you’ll see your code in action helping people get their jobs done with less friction.

What this means day-to-day:

• Direct customer connection - we encourage you to talk to users and understand their real challenges
• Collaborative partnership - work as equals with product managers and designers to find the best solutions
• End-to-end ownership - care about your work from conception through production and beyond
• Quality focus - balance shipping velocity with code quality and exceptional user experience
• Open communication - speak up with ideas, concerns, and feedback to help the team improve
• Continuous learning - embrace mistakes as learning opportunities and seek better approaches

We value transparency, honest communication, and engineers who genuinely care about the impact of their work. Subcontractors use Onetrace to prove their work has been carried out compliantly, with full traceability from start to finish. That not only makes their day-to-day smoother and more reliable, it also raises the standard across projects — ultimately leading to safer buildings for everyone to live and work in. And we think that’s something worth getting excited about.

The role

As a Senior Full-Stack Product Engineer at Onetrace, your mission is to translate complex user needs into elegant, high-impact solutions. You will take complete ownership of features from concept to deployment, architecting and building everything from performant React frontends to scalable Node.js services. You will help us to champion best practices, mentoring teammates, and contributing thoughtfully to the architectural decisions that shape our product's future.

What you’ll do:

• Own end-to-end delivery of features that solve real customer problems, from understanding user pain points through to shipped functionality across UI, application logic and database layers
• Build intuitive, performant interfaces that customers actually want to use—balancing user needs, accessibility, and technical constraints while ensuring features work reliably across devices and contexts
• Use customer feedback, analytics, and direct user insights to inform technical decisions, prioritise improvements, and validate that shipped features deliver measurable value
• Design and implement complex data flows, API integrations, and background processing systems that handle high-volume operations reliably while maintaining system performance and data integrity
• Partner with product, design, and customers to shape solutions early, translating business requirements into technical architecture while surfacing risks and opportunities that impact customer outcomes
• Mentor and coach other engineers, raising the bar for technical excellence through code reviews, pair programming, and architectural guidance

Beyond the tech

We are building a team of Product Engineers because we believe the most impactful work comes from those who are closest to the problems we’re solving. For us, engineering is not just about executing a specification; it’s about taking ownership of the user experience and the business outcome. Our engineers are partners in discovery and strategy, empowered to question assumptions, contribute to the "why," and use their technical creativity to build not just what is asked for, but what our users truly need.

Technical Skills:

• Node.js – primary backend framework
• MongoDB or other NoSQL database
• SQL databases and query optimisation
• RESTful API design and implementation
• Git – version control and collaborative workflows
• Backend testing strategies (unit, integration, end-to-end)
• Experience with monitoring, logging, and observability tools
• Knowledge of scalable system architecture and design patterns

Highly desirable:

• AdonisJS, NestJS or similar MVC frameworks
• AWS infrastructure and services
• Infrastructure as Code (Terraform or similar)
• Message queues and background job processing
• Caching strategies and performance optimisation
• CI/CD pipelines and DevOps practices

Nice to have:

• Security best-practices implementation
• Experience in a growth-stage startup or B2B SaaS
• Knowledge of the construction industry

What we offer:

• Enhanced parental leave
• Private medical insurance with Bupa
• Employee assistance programme
• Remote work abroad opportunities
• Apple MacBook and tech accessories
• Onetrace merch, regular team socials and annual company offsites

Onetrace is committed to diversity in the workplace and proud to be an equal opportunity employer. If you require a reasonable adjustment, please contact us. All information will be kept confidential and will only be used for applying a reasonable adjustment.

Please note that our office is a dog-friendly environment. Candidates should be aware that dogs are present in the workplace, which may include shared spaces. If you have allergies or concerns, please let us know in advance.

Seniority level: Mid-Senior level

Employment type: Full-time

Job function: Information Technology