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