Principal Frontend Engineer - TypeScript / React / €100,000 - €120,000 + meaningful equity | On-site, Dublin City CentreWe're working with an early-stage AI startup in Dublin, led by founders who'vebeen here before- they've built, scaled, and sold successful tech companies, and are now onto their most ambitious product yet.They're developing an AI platform that helps business leaders understand what'sreallygoing on across their teams - not through dashboards or KPIs, but through the actual conversations happening every day in meetings, calls, and chats.It's a complex problem, and they're looking for someone who's wired like a founder - an experienced Frontend Engineer who's built things from scratch, who thrives on autonomy, and who wants to have adirect hand in shaping how a product looks, feels, and performs.The RoleYou'll be joining as theFounding Frontend Engineer, taking full ownership of everything user-facing. You'll work side-by-side with the CTO to define architecture, build from first principles, and bring ideas to life.This isn't a role for someone who wants to "pick up tickets" - it's for someone who wants to make big technical calls, influence direction, and leave a mark.What You'll Be DoingBuilding and scaling the entire frontend using TypeScript, React, and Defining reusable component libraries and frontend architecture from scratch.Collaborating closely with design, backend, and AI teams to shape the product experience.Turning complex data into simple, elegant visual interfaces.Setting technical direction for frontend standards, performance, and scalability.What You'll BringSenior-level experience in TypeScript / React / (or similar modern frameworks).Strong software engineering fundamentals - you can pick up any unfamiliar codebase and reason about how it works.Experience working in a startup or fast-moving SaaS environment.Ideally, some founder or early-stage experience - you've built or owned something before, even if it failed.A hands-on, problem-solving mindset - you don't wait for direction, you create it.Nice to HaveExperience building component libraries or design systems used across multiple teams.Some backend understanding, APIs, integration).Curiosity about AI and LLM-driven products.Why JoinYou'll be joining a team full of founders - everyone here has built something before.On-site 5 days a week in a new Dublin City Centre office - close collaboration, fast iteration.Salary up to €120k + founding-level equity.Huge growth potential - future path to leadershipAutonomy, speed, and genuine ownership from day one.If you love early-stage building - where decisions matter, ideas move fast, and your work defines what the company becomes - this is that opportunity.If you're the type of engineer who's ever thought,"I could build this better myself,"- now's your chance to prove it.To speak in absolute confidence about this opportunity please contact Jack Tyrrell, Specialist Recruitment Consultant at MCS Group or send an up to date CV via the link provided.If this position is not right for you, we may have others that are. Please visitto view a wide selection of our current jobs.All conversations will be treated in the strictest of confidence.