Senior Full Stack Engineer - Fast-Growth SaaS Scale-Up Belfast (1-2 Days in Office) | High Autonomy & Impact MCS Group is proud to partner exclusively with a fast-growing, venture-backed tech start-up entering an exciting scale-up phase. With strong investment, a product already gaining global traction, and an ambitious roadmap ahead, we're now seeking a Senior Full Stack Engineer to help shape the future of our platform. This isn't just another development role-it's your chance to make a tangible impact. You'll be building meaningful features, solving complex technical challenges, and directly influencing product direction in a high-trust, high-responsibility environment. What You'll Do Design, build, and maintain high-quality features across backend and frontend systems Work closely with engineers, designers, and product managers in an agile, collaborative setting Take ownership of problems end-to-end, from discovery through delivery Contribute to architectural decisions and scalability planning Leverage innovation-including AI-to deliver creative, market-leading solutions What We're Looking For Proven experience delivering full-stack applications in modern frameworks Someone who thrives in the fast-moving, dynamic world of start-ups and scale-ups Passion for building and scaling SaaS products Adaptable, tech-agnostic mindset-able to quickly pick up new tools, languages, and frameworks Excitement about AI and its potential to transform product development Experience in CI/CD workflows and cross-functional agile teams Why Join Us Impact from Day One: High ownership and the ability to shape the product and the company's direction Innovation-First Culture: Work with cutting-edge technologies in a team that embraces experimentation Growth Phase Opportunity: Be part of a rapidly scaling product with global reach Competitive salary up to £85K + private healthcare Mission-driven team with a supportive, collaborative culture If you're an engineer who loves tackling new challenges, experimenting with emerging technologies, and making a real difference in a fast-paced, high-growth environment-this is where you belong. To speak in absolute confidence about this opportunity, please send an up-to-date CV via the link provided or contact Matthew Rainey, Specialist Tech Recruiter, at MCS Group on . Not the right fit? Visit to browse other exclusive tech roles. All conversations will be treated with the strictest confidence. Skills: senior software developer senior software engineer AI start up Technical lead