Overview

We are working with an ambitious and well-funded early-stage B2B SaaS company building something transformative. They are hiring a Senior or Principal Full-Stack Software Engineer to help lay the technical foundations of their platform and influence engineering direction and long-term product strategy.

Responsibilities

• Design and implement scalable, secure, and high-performance systems.
• Own and evolve core parts of the platform architecture.
• Collaborate with product, commercial, and leadership teams to align technical delivery with strategic goals.
• Write clean, maintainable code across the full stack and contribute to reviews and debugging.
• Bring new ideas and best practices to continuously elevate engineering standards.

Qualifications

• 5+ years of experience working with JavaScript/TypeScript as a full-stack engineer.
• Experience leading projects or teams in a technical capacity.
• Previous exposure to early-stage startups, ideally in B2B SaaS.
• Strong proficiency in modern front-end frameworks (particularly React).
• Experience designing and integrating REST or GraphQL APIs (bonus if you've built SDKs or documentation).
• Solid understanding of SQL and NoSQL databases and backend architecture.
• Familiarity with cloud platforms such as AWS, Azure, or GCP.
• A pragmatic, product-first mindset—someone who values simple solutions and rapid iteration.
• Strong collaboration and communication skills.

Benefits

• Competitive salary
• 25 days holiday + bank holidays
• Share options in a fast-growing business
• Private healthcare (including dental and optical)
• Flexible working (remote or hybrid - dog-friendly office in London available)
• Strong career development and influence in a key hire

Legal / Notes

• UK right to work required - unfortunately, visa sponsorship isn't available.
• The team is passionate about diversity, inclusion, and building an environment where everyone can thrive and do their best work.
• If you're a hands-on engineer excited by the idea of helping build a product from the ground up and want to join a team that values innovation, ownership, and velocity, we would love to hear from you.