Senior Software Engineer - Agentic Development

Cracking opportunity for a seriously capable Senior Software Engineer to join an burgeoning, highly ambitious, founder-led SaaS scale-up as it gears up for a period of hypergrowth.

Our client has built a sophisticated B2B software platform, established a proven product model and secured Series B investment to accelerate its next stage of growth.

The product works. The client base is already global. The commercial opportunity is substantial. The founders have serious ambitions.

Now they’re rethinking how the entire engineering operation works.

And that’s where you come in.

This isn’t a conventional Senior Software Engineer role. We’re looking for engineers who have already fundamentally changed the way they build software.

Engineers who have moved beyond writing everything themselves and now use coding agents to do the heavy lifting - directing implementation, interrogating outputs, verifying results and taking complete ownership of what ships.

The agents write the code. You make the engineering decisions.

You’ll join a business that’s moving away from traditional, developer-heavy engineering structures towards smaller, exceptionally capable teams built around agent-first development.

Working with a formidable technology leadership team that’s challenging the conventional rules of software engineering., you’ll help shape how a complex, established SaaS platform is developed, improved and scaled.

This is proper engineering. Complex systems, demanding production environments, difficult technical decisions and plenty of opportunity to get your hands dirty.

You’ll be expected to break down complex problems, turn requirements into clear, executable specifications, direct coding agents through implementation and use automated verification to establish that what they’ve produced actually works. And when the agents get stuck, go off-piste or produce something that looks convincing but isn’t?, We’re looking for engineers who enjoy the growing pains of ambitious scale-ups. People who thrive on complexity, move quickly, challenge conventional thinking and don’t need layers of management telling them what to do.

You’ll probably have a few operational scars. You’ll understand that scaling sophisticated software products is rarely clean or straightforward. And you’ll be excited by the prospect of helping build an engineering function that operates very differently from the one you joined.

This role will suit engineers who are already living in the future of software development - not those waiting for someone to show them how to get there.

• Strong senior-level software engineering experience, ideally gained building and scaling complex B2B SaaS products.
• Proven hands-on experience using coding agents as your primary method of implementing production software.
• Professional engineering experience with Python and TypeScript.
• Exceptional code comprehension, problem decomposition and technical judgement.
• Experience reviewing, testing and automatically verifying agent-generated code.
• Tangible evidence that your approach has improved engineering productivity, speed or quality.
• The communication skills and ownership mentality to thrive in a small, high-performing engineering team.

Experience orchestrating multiple coding agents in parallel would be particularly interesting, although sophisticated single-agent workflows are equally worth discussing. We’re not precious about tooling. Claude Code, Codex, Cursor, Devin - what matters is how effectively you use it.

Django, React, PostgreSQL, AWS and experience developing agent guardrails would all be advantageous., If you’re a seriously capable software engineer who’s already stopped measuring productivity by how much code you personally write, this could be a very interesting conversation.

• £115k - £145k basic salary DOE.
• Predominantly remote working with very occasional London meetings.
• A Series A-backed SaaS business with an established product and ambitious growth plans.
• Direct exposure to experienced technology leadership and a founder-led management team.
• Significant technical ownership and influence over the engineering operating model.
• The opportunity to help shape a genuinely agent-first engineering function from an early stage.