Senior Backend Engineer

We’re looking for a Senior Backend Engineer to design and own the systems that power our product. You will take end-to-end ownership of features with particular depth in APIs, data flows, and backend architecture, while remaining full-stack - comfortable shipping the frontend work needed to see a feature through without handing off. You’ll take operational responsibility for what you build, help shape the team’s technical direction, and mentor others as you go.

About Onetrace

Great products start with great people.

Our focus on user experience has helped us become the leading software for fire protection subcontractors across the UK.
 We build tools that actually work on the ground - fast, intuitive, and simple to use.

Onetrace is growing quickly, recognised as one of the fastest-growing companies in the UK and in London’s construction sector. We’re bootstrapped, profitable, and on a mission to become a global ConTech leader.

Join a smart, ambitious team where your ideas matter and your work shapes what’s next. Learn more about life at onetrace here .

What you’ll do

• Own end-to-end delivery of features that solve real product problems, with particular depth in the application logic and database layers, through to shipped functionality across the stack
  
• 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
  
• Take operational responsibility for what you build - from architecture and implementation through to how it behaves in production
  
• Build performant, well-tested backend services, while staying hands-on with the frontend so you can take a feature all the way through without handing off - avoiding a backend-only silo
  
• Use product metrics, engineering signals, and feedback from your team to inform technical decisions, prioritise improvements, and validate that shipped features deliver measurable value
  
• Partner with product and design to shape solutions early, translating requirements into technical architecture and surfacing risks and opportunities that impact outcomes
  
• Mentor and coach other product engineers, raising the bar for technical excellence
  

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.

Our engineering culture

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:

• We encourage you to talk to users and understand their real challenges
  
• Work as equals with product managers and designers to find the best solutions
  
• Care about your work from conception through production and beyond
  
• Balance shipping velocity with code quality and exceptional user experience
  
• Speak up with ideas, concerns, and feedback to help the team improve
  
• 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.

Want to dig deeper?

If you’re curious about what it’s really like to build at Onetrace, we’ve written more about our approach, straight from the people you’ll be working with:

• Our Product Engineering Culture - by Luca Carangella, Director of Product Engineering, on how we think about engineering and collaboration.
  
• Building Products for Subcontractors - by our Co-Founders, Lewis and Greg, outlining the mindset and manifesto that guide how we build.
  

What you’ll bring

Essential

• JavaScript / TypeScript - core programming languages
  
• Node.js - primary backend framework
  
• SQL databases and query optimisation
  
• MongoDB or other NoSQL database
  
• 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
  
• Familiarity with modern AI tools and a habit of staying up to date with how they can improve engineering workflows
  

Highly desirable

• AdonisJS, NestJS or similar MVC frameworks
  
• AWS infrastructure and services
  
• Infrastructure as Code (Terraform or similar)
  
• Distributed systems experience
  
• 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
  

Hybrid guidelines

We operate a hybrid working model, with a minimum expectation of 2-3 days per week in the office. This is a core part of how the role works and isn’t something we’re flexible on.