Product Engineer (Staff/Principal)

Product Engineer (Staff/Principal) Want to join us at a well-funded AI startup that's really going places? Build product that customers love, by AI, in production, for real revenue at 5D. Work in a low-ego, high-learning environment. Apply We usually respond within a day About Us: Fifth Dimension is bringing vibe working to document-heavy industries 🌈. Today we work with real estate businesses in the US, EU and APAC, automating complex tasks, extracting valuable insights from documents, and empowering professionals to focus on high-impact work. Our AI workspace transforms how large investment managers and developers handle leases, development documents, and investment decisions. We're a London and New York based startup with an ample runway, backed by Tier 1 European and American investors. Our founders, Johnny Morris and Dr. Kate Jarvis bring a powerful blend of expertise (and spice 🌶️): Johnny has 17+ years applying data and analytics to Real Estate, while Kate holds a Stanford PhD and 12 years of executive experience across Silicon Valley and London startups. At Fifth Dimension, we're demanding yet encouraging, valuing experimentation and kind challenges. Our company values, Own It, Ship It, and Don't Be Boring , drive us to deliver exceptional results while fostering a culture of innovation and continuous improvement. The Challenge It's 9 AM on a Monday. You're reviewing usage analytics from last week's release and notice a drop-off in a key workflow—you sketch out a hypothesis and a fix before standup. By noon, you've shipped a prototype using Claude Code that rethinks how users navigate large document sets, and you're demoing it to a product manager and a customer success lead. By Wednesday, you're on a call with a major real estate firm, listening to how they actually use the platform day-to-day—and you spot an opportunity nobody had articulated yet. By Thursday, you've shaped that insight into a spec, got buy-in, and started building. By Friday, you're celebrating with the team as a customer tells you: "This is exactly what we needed." About You You're an expert software engineer who thinks in terms of user outcomes, not just code. You don't just ship features—you understand the problem space deeply, make sharp product calls, and build solutions that customers didn't know they needed until they can't live without them. You've honed your craft through years of practice across the full stack, from performant backends and well-designed APIs to responsive, polished frontends. You have strong product intuition—you know how to talk to customers, read between the lines of a feature request, and make pragmatic trade-offs between scope, speed, and quality. You're proficient with AI coding assistance tools like Claude Code, leveraging them to accelerate development and focus on higher-level product and architectural challenges. You understand that modern engineering means effectively collaborating with AI to maximise your productivity and creative potential. Details don't escape you. You take pride in the end-to-end user experience—from the API contract to the loading state to the edge case that only one customer hits. As someone who thrives in fast-paced environments, you adapt quickly and mentor other engineers while collaborating effectively with commercial teams and customers. You're passionate about your personal growth and see each complex problem as an opportunity to expand your capabilities. You actively seek challenges that push the boundaries of what's possible and value environments where you can both contribute your expertise and continue to evolve as an engineer. Your Impact Reporting to our CTO Chen, you'll own and shape core product areas end-to-end—from discovery and design through to architecture, implementation, deployment, and customer adoption. Working closely with our skilled engineering team and commercial stakeholders, you'll combine deep technical ability with strong product sense to build capabilities that deliver tangible value to enterprise customers and drive the business forward. Day to Day, You Will Think like a Product Manager+ : Own core product areas while balancing technical excellence with business impact—you don't wait for a spec, you help write it Own end-to-end delivery of complex features from discovery and definition through to production deployment and customer adoption Talk to customers regularly—understanding their workflows, pain points, and unarticulated needs to inform what you build Collaborate with product, design, and commercial teams to shape the roadmap and translate customer insight into robust technical solutions Leverage AI coding tools like Claude Code to accelerate development workflows Lead development of the systems that underpin our platform: Scalable APIs and backend services that power document processing, data extraction, and agentic workflows Reliable streaming and event-driven architectures for real-time user experiences Frontend experiences that make powerful AI capabilities intuitive and accessible Integrations with enterprise systems and third-party platforms Implement data privacy and security by design Champion engineering best practices: testing, observability, CI/CD, and infrastructure-as-code Mentor other engineers and help establish engineering and product-thinking best practices Invest in your own growth by taking on ambitious technical challenges and expanding your expertise Apply our engineering philosophy: intellectual honesty, effective time management, clear communication, and innovation Our Values and Engineering Culture At 5D, we embody three core principles: Own it, Ship it, and Don't be boring . Our engineering team values: Product-Minded Engineering : Understanding the "why" behind features and using technical expertise to inform product decisions Intellectual Honesty : Backing discussions with data and acknowledging knowledge gaps Effective Time Management : Setting clear timebox and abandoning approaches that aren't working Clear Communication : Writing self-documenting code and providing detailed explanations Innovation Mindset : Forming well-reasoned opinions backed by data and continuously learning Personal Growth : Supporting your development through challenging work and opportunities to expand your expertise Intellectual Curiosity and Honesty in Action: An Example Here's an example of how we work: Early in our journey with AI, one of our engineers discovered that certain words like "concise" or "creative" had disproportionate effects on model outputs—we called them "demon words." Rather than accepting this as an immutable quirk, they spent a week methodically tracking down every instance in our codebase, testing alternatives, and documenting the patterns they found. This intellectual curiosity to understand the "why" behind technical oddities, combined with the honesty to admit what we didn't yet understand, led to significant improvements in our product's reliability. At 5D, we value this combination of curiosity and honesty above all—the willingness to dive deep into unexpected behaviors and openly share both successes and failures with the team. What We're Looking For Experience in high-growth startups or fast-paced tech environments Track record building software in organizations with excellent engineering practices History of owning end-to-end product development, from discovery and definition to delivery and customer adoption Demonstrated product instinct—you've shaped what gets built, not just how it gets built Strong Python skills with a track record of shipping customer-facing features on critical paths Experience designing and building high-quality APIs, services, and distributed systems Solid frontend skills and experience building polished, user-facing applications Proficiency with AI coding assistance tools (Cursor, GitHub Copilot, Claude Code) Intellectual curiosity and honesty—digging deep into problems and sharing findings openly Proven ability to make technical decisions that balance immediate user needs with long-term architecture Exceptional communication abilities for explaining complex concepts to diverse audiences Ambition and resilience—we're a seed-stage company tackling ambitious challenges Commercial awareness—delivering continuous value to customers is essential Passion for personal growth and continuous learning Nice to Have (But Not Required) Experience with cloud infrastructure (GCP, AWS, or Azure) and container orchestration Past experience in real estate, law, or finance Background with robust software testing and deployment practices Experience with component-based system design and microservices Experience with event-driven architectures and streaming systems Contributions to open-source projects or broader technical communities What We Offer You We're building something extraordinary and we want extraordinary people. Our benefits package goes beyond the standard startup offering—from tailored support for life's challenges (IVF, gender-affirming care, ADHD diagnosis, and more), to meaningful parental leave. £100,000-160,000 salary per annum + meaningful equity (on a standard vesting schedule) 📈 Enhanced Pension Contributions - 5% Unlimited annual leave £100 monthly well-being budget Tailored support for exceptional challenges. This looks different for everyone, but can include contributions to: Gender-affirming care Private specialist and scans for an injury ADHD / Autism diagnosis IVF Therapy Enhanced Parental Leave 14 weeks full pay (followed by standard statutory pay) for primary caregiver 6 weeks full pay for secondary caregiver Electric Car Scheme (salary sacrifice) £1000 annual training budget The Process Submit your CV, along with answers to the handful of questions we ask of every candidate A call with our CTO to explore the initial fit A live task and competency interview An in person culture fit interview with a range of people across the business, including the 2 founders Alternatively we offer a paid-for one-week trial for candidates who are available for the setup Department Product & Engineering Locations London, New York, Singapore Remote status Hybrid About Fifth Dimension We're building the AI platform that powers every real asset decision. Leases, financial models, data rooms, investment memos - for decades, the people making billion-dollar calls have done it with Excel, PDFs, and an analyst working late. We're changing that. 5D turns the most complex documents and data in finance into structured intelligence that professionals actually trust. We're a Series A company with offices in London, New York, and Singapore, working with the firms that finance and manage the built world. That's every skyscraper, data centre, wind farm, and bridge - in the $393 trillion real assets market. We help them drive alpha, close faster, and make better calls. We ship daily, building a product that compounds: every data source, every skill, every customer correction makes the platform more powerful than the last. Johnny and Kate founded 5D from a shared frustration. Johnny spent 17 years inside institutional real estate, close enough to the problem to know exactly where the pain was. Kate spent 12 years building enterprise software, close enough to know what it would take to fix it. They started 5D because no one else was doing it right, and they still run it that way: demanding, direct, and genuinely excited about what they're building. The decisions 5D powers shape cities, funds, and careers. We're direct with each other, high on craft, and genuinely invested in each other winning, and we build better for it. If that's the kind of place you want to spend your time, let's talk. Founded in 2023 Co-workers 30+