Member of Product Staff, Designer/Design Engineer (London)

Tessl

Tessl is a fast-growing Series A startup based in London, founded by Guy Podjarny. We’ve raised over $100M from world-class investors including Index Ventures, Accel, GV, and Boldstart, and in 2025 we were ranked #2 in Sifted EU’s B2B SaaS Rising 100 and #20 in Sifted's AI 100. At Tessl, we are building the context layer for AI coding agents, and a platform for AI-native software development. As an early member of the team, you’ll help shape how we build, scale and support a company operating at the edge of AI and software development. About the role Tessl is building the foundational infrastructure for how developers work with AI agents: the systems, standards, and tooling that make agent-assisted software development reliable, repeatable, and trustworthy at scale. We are a small team working on a genuinely new class of problem, and design is central to how we solve it. We are looking for a Member of Design Staff who brings real craft and genuine curiosity. You will work closely with product managers, engineers, and researchers to shape how developers interact with technically complex systems and workflows. This is not execution work within a settled product. The patterns are still forming, and the person we hire will have a direct hand in shaping them. We also expect this person to be building a genuinely AI-native design practice: using the best available tools to move faster, think more clearly, and raise the quality of our work. We are not looking for someone who uses AI occasionally. We want someone who is actively developing how they work with it. What you will work on * Design clear, usable interfaces across core product surfaces and developer workflows, balancing simplicity with the depth and configurability that expert users need. * Translate nuanced system concepts into experiences that feel considered rather than overwhelming, grounding design decisions in real user behaviour and research. * Run user research with developers and engineers, turning genuine observations into well-reasoned, specific design decisions. * Collaborate daily with product managers and engineers throughout the full cycle of work: contributing early, iterating often, and treating designs as living documents rather than fixed deliverables. You are comfortable taking the lead on design direction while staying responsive to how the product evolves around you. * Contribute to a growing design system, bringing visual rigour and coherence to shared foundations that will hold up as the product and team scale. * Develop an AI-native design process: use current tools across research, prototyping, and visual production, share what you learn with the team, and raise the bar for how design work gets done. What we are looking for * Experience: 3 to 5 years of experience in product design, or equivalent, with a portfolio showing end-to-end ownership of real, shipped work. Strong visual design sensibility evident throughout. * Technical fluency: A track record of designing for technically sophisticated users. You do not need to be an engineer, but you should be genuinely curious about how the systems you design for actually work. * Tools and working practice: Strong proficiency in Figma, including component architecture and design system contribution. Comfort using AI tools as a serious part of your workflow, from research through to production. Familiarity with tools such as Dovetail is a plus. * Collaboration: You work well in a fast-moving environment where priorities can shift and process is still forming. You are confident enough to take the lead on design direction and bring a clear point of view, but equally comfortable running with an idea that comes from elsewhere in the team. You know the difference between holding your ground on something that matters and being flexible when the situation calls for it. Daily collaboration with engineers and product managers is the norm here, not the exception. * Domain experience: Prior experience in developer tools, productivity software, or AI/ML applications. You understand what it means to design for expert users. We do not have all the answers yet. This is a role where you will help define new patterns, work at the edge of what is known, and shape how design is practised at a company that is still figuring things out in the best possible way. If that kind of challenge excites you, and you feel you would be a strong fit even if you do not meet every criterion listed, we would encourage you to apply. APPLICATION PROCESS Here’s an outline of what you can expect during our interview process: 1. Introductory call 2. Portfolio Review with Designer(s) 3. Case study / White boarding 4. Meet with Head of Product 5. Leadership discussion We care deeply about the warm, inclusive environment we’re building at Tessl and we value diversity – we welcome applications from those typically underrepresented in tech. If you like the sound of this role but are not totally sure whether you’re the right person, do apply anyway! LEARN HOW WE THINK AND WORK * On Tessl, The AI Native Development Startup * Announcing skills on Tessl: the package manager for agent skills * Podcast Episode: The End of Fragmented Agent Context, Guy Podjarny Tessl CEO

Tessl

Tessl is a fast-growing Series A startup based in London, founded by Guy Podjarny. We’ve raised over $100M from world-class investors including Index Ventures, Accel, GV, and Boldstart, and in 2025 we were ranked #2 in Sifted EU’s B2B SaaS Rising 100 and #20 in Sifted's AI 100. At Tessl, we are building the context layer for AI coding agents, and a platform for AI-native software development. As an early member of the team, you’ll help shape how we build, scale and support a company operating at the edge of AI and software development. OVERVIEW OF ROLE Join our engineering team to build real-time AI Native workflows, tooling, and interfaces that will reshape how developers create and maintain software. As a Software Engineer, you’ll be versatile and independent, excited to work with cutting-edge AI tools to build great products. We move quickly, but with purpose - balancing speed with collaboration and thoughtful execution. You’ll collaborate closely with product, design, and the wider Engineering team to bring AI Native development to life in a fast-paced, high-trust environment. WHAT YOU’LL DO No two days will be the same at Tessl! You’ll have a high level of autonomy and be able to make decisions based on what you believe will help you deliver the most success. Here’s an insight into just a few of the things you would be doing: * Design and implement new functionality that you discussed and reviewed with the product team * Spin up a proof of concept to showcase an innovative idea you’ve been thinking about * Rapidly prototype a new language integration for our code generation pipeline, then develop a plan for a scalable implementation. * Pair with a designer to fine-tune interactions in the UI, CLI or existing AI coding agents, making the user experience more intuitive and slick * Integrate a third-party service, e.g. for notifications, so we can focus our own cycles on Tessl’s core capabilities * Collaborate with other teams to plan an architecture that supports collaboration across the platform * Establish an end-to-end testing strategy to increase our confidence when deploying new features to production * Share your technical vision for a new product capability you’ll be leading with the wider engineering team for feedback and alignment WHAT WE’RE LOOKING FOR ESSENTIAL * Proven experience (typically 5+ years or equivalent) as a Software Engineer. You care about code modularity, structure and aesthetics and have firsthand experience in how software is built across teams and environments * Equally comfortable contributing to a mature codebase with strict CI criteria or hacking up a quick prototype to prove/disprove an assumption * Proven experience leveraging the best AI coding tools and agents to accelerate and enhance your own work and efficiency * Comfortable with fast-paced, high-autonomy environments: you’ve ideally thrived in an early-stage startup before * You have demonstrated usage of AI tools in your day-to-day work, and be excited about experimenting, learning, and harnessing the potential of new AI tools and approaches to transform software engineering NICE TO HAVE * Background in AI products or developer tools * Experience in rapid prototyping environments * Programming polyglot experienced in several languages of different paradigms (e.g.: JavaScript/TypeScript, Python, C or C++, Haskell, etc.) * Experience collaborating with AI researchers and bridging between research-focused and engineering-focused teams * Experience building & scaling REST APIs, particularly those conforming to JSON:API * Comfortable working on infrastructure (e.g., setting up CI pipelines, navigating Kubernetes) * If you have a personal or open-source project you’d like to share, we’d love to see it (GitHub links welcome!) SALARY AND BENEFITS Office: Our brand new 10,000 sq. ft office is in the AI hub of Kings Cross, London. We have generous catering and have regular social events such as team lunches, drinks and more. We require all staff to be in our London HQ at least 3 days a week on our anchor days of Monday, Tuesday and Thursday. Salary: We offer a competitive salary based on experience and skills, benchmarked against industry standards. Benefits: 25 days holiday, health insurance, including dental and vision, which extends to partners and dependents, as well as a company-matched pension. We also provide a commuting stipend for those who live outside London, and a cycle to work scheme. APPLICATION PROCESS Here’s an outline of what you can expect during our interview process: 1. Introductory Call 2. Take-Home Exercise 3. On-site Technical Session 4. Culture Conversation 5. Leadership Discussion Throughout the process, if you have any specific requirements or need adjustments, please let us know: we’re happy to accommodate. We care deeply about the warm, inclusive environment we’re building at Tessl and we value diversity – we welcome applications from those typically underrepresented in tech. If you like the sound of this role but are not totally sure whether you’re the right person, do apply anyway! LEARN HOW WE THINK AND WORK * On Tessl, The AI Native Development Startup * Announcing skills on Tessl: the package manager for agent skills * Podcast Episode: The End of Fragmented Agent Context, Guy Podjarny Tessl CEO

Tessl

Tessl is a fast-growing Series A startup based in London, founded by Guy Podjarny. We’ve raised over $100M from world-class investors including Index Ventures, Accel, GV, and Boldstart, and in 2025 we were ranked #2 in Sifted EU’s B2B SaaS Rising 100 and #20 in Sifted's AI 100. At Tessl, we are building the context layer for AI coding agents, and a platform for AI-native software development. As an early member of the team, you’ll help shape how we build, scale and support a company operating at the edge of AI and software development. ABOUT THE ROLE We're looking for a Member of Product Staff — a senior, hands-on product manager who can own ambiguous, high-stakes problems end to end and help define how product is practised as the team grows. This is a generalist role. The patterns for how developers work with AI agents are still forming, and you'll have a direct hand in shaping them across the product — from the CLI and core platform to the new bets we'll place as we expand. Much of the work is 0-to-1: you'll shape product direction amid genuine ambiguity, translate fast-moving model and research breakthroughs into experiences developers trust, and decide what's worth building when there's no settled playbook. We also expect this person to be building a genuinely AI-native product practice: using the best available tools to think more clearly, move faster, and raise the quality of the work. We're not looking for someone who uses AI occasionally — we want someone actively developing how they work with it, and setting the standard for the team. WHAT YOU'LL WORK ON * Own product areas end to end. Take problems from early concept through discovery, definition, launch, and iteration — setting priorities for a cross-functional team and making the calls on what matters most. * Develop deep product sense for developer workflows. Spend real time with developers and engineering teams to understand how they think, where they struggle, and where AI creates the most leverage. Turn those observations into specific, well-reasoned product decisions. * Translate frontier capability into product. Partner closely with engineering and research to turn new model capabilities and agentic breakthroughs into reliable, high-value developer experiences. * Shape strategy, not just execute it. Bring a clear point of view to roadmap and direction. You'll be in the room for strategy conversations and expected to help shape outcomes, not just respond to decisions already made. * Lead through influence. Act as the connective tissue between engineering, design, research, GTM and leadership — and as a credible voice with customers. Keep a globally-minded, fast-moving team rowing in the same direction. * Maintain a high quality bar at speed. Ship quickly without losing rigour, and hold the line on quality and developer trust even when the product is changing fast. * Build an AI-native product process. Define which tools and workflows raise quality and pace, share what you learn, and help set how product gets done at Tessl. WHAT WE'RE LOOKING FOR * Experience: Roughly 6+ years in product management (or equivalent), with a track record of shipping real, technically demanding products end to end. Comfortable operating at a senior IC level with significant autonomy. * Product sense & judgment: Strong instincts for what to build and why, backed by good business judgment and the ability to reason clearly under ambiguity and incomplete information. * Technical fluency: A track record of building for technically sophisticated users — developers, engineers, or data professionals. You don't need to be an engineer, but you should be genuinely curious about how the systems you build for actually work, and able to partner with research and engineering at a technical level. * 0-to-1 instinct: Comfortable shaping direction where there's no settled product, market, or process. You're drawn to ambiguity rather than unsettled by it. * Collaboration & communication: Excellent communicator who can align and influence engineers, designers, researchers and leaders who think differently to you. Confident enough to hold a point of view, flexible enough to run with the best idea wherever it comes from. * Domain experience (a plus): Developer tools, AI/ML applications, or productivity infrastructure. Exposure to CLI tooling, agentic workflows, or evaluation systems is a genuine advantage. We don't have all the answers yet. This is a role where you'll help define new patterns, work at the edge of what's known, and shape how product is practised at a company still figuring things out in the best possible way. If that excites you, and you feel you'd be a strong fit even if you don't meet every criterion listed, we'd encourage you to apply. SALARY AND BENEFITS Office: Our brand new 10,000 sq. ft office is in the AI hub of Kings Cross, London. We have generous catering and regular social events such as team lunches, drinks and more. We require all staff to be in our London HQ at least 3 days a week on our anchor days of Monday, Tuesday and Thursday. Salary: We offer a competitive salary commensurate with experience and skills and employee share options, benchmarked against industry standards. Benefits: 25 days holiday, health insurance, including dental and vision, which extends to partners and dependents, as well as a company-matched pension. We also provide a commuting stipend for those who live outside London, and a cycle to work scheme. APPLICATION PROCESS 1. Screening call 2. Case study presentation (with the hiring panel) 3. Final round — cross-functional collaboration, leadership, and a hands-on PM workshop 4. Leadership Chat We care deeply about the warm, inclusive environment we’re building at Tessl and we value diversity – we welcome applications from those typically underrepresented in tech. If you like the sound of this role but are not totally sure whether you’re the right person, do apply anyway! LEARN HOW WE THINK AND WORK * On Tessl, The AI Native Development Startup * Announcing skills on Tessl: the package manager for agent skills * Podcast Episode: The End of Fragmented Agent Context, Guy Podjarny Tessl CEO