Senior Backend Engineer | Fast-Growth SaaS Scale-Up | Remote (UK-Based) with Monthly Meet-ups Haystack is working with an established and profitable SaaS scale-up that’s currently hiring two Senior Backend Engineers to join their growing team. You’ll be working directly with the CTO and play a crucial role in shaping the next phase of the company’s technical and product evolution. This is a fantastic opportunity to join a high-performing, pragmatic, and low-ego engineering culture, where your ideas will be heard, and your work will have real impact from day one. About the Company Product-led SaaS scale-up with an exceptional reputation for technical excellence and customer experience Profitable, secure, and growing fast with a loyal and expanding customer base Competing in a traditionally outdated market with a disruptive, high-performing platform Modern tech stack, strong internal processes, and a focus on engineering quality The Role As a Senior Backend Engineer, you’ll: Work across all areas of the platform (backend services, core technology, and optionally web apps) Own and deliver high-impact features that improve performance, scalability, and customer experience Collaborate closely with customer success teams to remain responsive to customer needs Play a key part in growing and mentoring the engineering team over the next 12–24 months Contribute to technical decisions and architecture in a high-trust environment Tech Stack Backend: Go, PostgreSQL, Redis, Timescale, Temporal.io Deployment: Kubernetes on GCP & AWS Other languages: C#, C++ (core tech), Svelte & TypeScript (web apps) Development Environment: Linux-based, focused on fast dev/test loops What We’re Looking For 10 years' experience in software engineering, ideally in start-up/scale-up environments 2 years of commercial Go experience Deep experience with at least one of: Go, C#, Java, C, or C++ Proven background in building and operating cloud services or complex distributed systems Comfortable in a Linux dev environment and working with infrastructure tooling Strong ownership mindset, with the ability to take a feature/project from idea to deployment Experience mentoring engineers and contributing to a supportive, collaborative team culture Willingness to participate in an on-call rota (after onboarding) UK-based and happy to travel monthly for team meetups (usually in Cambridge or other locations in the South/East of England) Nice-to-Haves Experience or interest in DevOps/infrastructure: observability, IaC, cloud environments, deployments, etc. Why This Role? High-impact position in a company that values technical excellence and close customer collaboration Work with experienced engineers in a flexible, remote-friendly setup (with monthly in-person time) Opportunity to grow with the business and take on increasing leadership responsibilities Flat structure, fast decision-making, and genuine autonomy Interested? If you’re an experienced backend engineer looking for a hands-on, high-ownership role in a fast-growing, technically-minded scale-up, let’s chat. Apply now and hear back within 48 hours.