Senior Backend Engineer (£60k-£80k) at Carno

This is a job that Jill, our AI Recruiter, is recruiting for on behalf of one of our customers. She will pick the best candidates from Jack's network. The next step is to speak to Jack. Job Title Senior Backend Engineer (Laravel) Salary £60,000-£80,000 Company Description Carno is a seed-stage London-based startup building the operating system for the UK's renewable energy installation industry. Their platform streamlines workflows for heat pump installers, cutting administrative time by up to 90% and powering thousands of installations to accelerate home decarbonisation at scale across the country. Job Description Join a lean founding team of four as a Senior Backend Engineer to own the architecture of a mission-critical Laravel platform. You will design multi-tenant SaaS systems, build event-driven pipelines, and develop scientific calculation engines for building thermodynamics. This high-impact role directly influences the UK's transition to low-carbon electric heating. Location London, UK (Remote) Why this role is remarkable High ownership at a seed-stage company where your architectural decisions define the platform's foundation rather than maintaining legacy designs.Direct daily collaboration with the founding team, including the CTO, CEO, and CPO, in a fast-moving, high-autonomy environment.Tangible real-world impact by building software that accelerates the deployment of renewable energy and home decarbonisation across the UK. What You Will Do Build and maintain a complex multi-tenant SaaS architecture using Laravel, ensuring strict tenant isolation and sophisticated per-organisation business logic.Design and implement asynchronous queue pipelines and event-driven patterns using Redis pub/sub to handle high-frequency data workflows.Develop and manage shared internal Composer packages and integrate third-party property data APIs to power the core installation workflow. The ideal candidate 3+ years of professional Laravel engineering experience with proven expertise in building multi-tenant SaaS and managing per-tenant databases.Strong fundamentals in modern infrastructure, including AWS (EC2, RDS, S3), Docker containerization, and managing CI/CD pipelines across multiple repositories.Proficient in security best practices, including OAuth 2.1, RBAC, and secret management, with a solid grasp of authorisation boundaries in multi-tenant environments. Who are Jack & Jill? Ok, I'll go first. I'm Jack, an AI that gets to know you on a quick call, learning what you're great at and what you want from your career. Then I help you land your dream job by finding unmissable opportunities as they come up, supporting you with applications, interview prep, and moral support. And I'm Jill, an AI Recruiter who talks to companies to understand who they're looking to hire. Then I recruit from Jack's network, making an introduction when I spot an excellent candidate. How does this work? Jack's an AI agent for job searching and career coaching. He works for you.Jill is the AI recruiter working for the company. She recruits from Jack's network.If it's a match and the company wants to meet you, they'll make the intro. In the meantime, if you'd like, Jack will send you excellent alternatives. We never post fake jobs This isn't a trick. This is an open role that Jill is currently recruiting for from Jack's network. Sometimes Jill's clients ask her to anonymize their jobs when she advertises them, which means she can't share all the details in the job description. We appreciate this can make them look a bit suspect, but there isn't much we can do about it. Give Jack a spin! You could land this role. If not, most people find him incredibly helpful with their job search, and we're giving his services away for free.