Senior Growth Engineer - Contract

Department: Engineering

Day rate: Competitive

Length: 3-month initial contract. Potential to convert to permanent for the right person.

Mission: Elevate later life for everybody and build the care sector of the future.

Office Policy: Hybrid with two core office days per week.

Office Location: London Bridge, London, UK

The Opportunity: Lottie's marketplace connects millions of families with the right care at the right time. We've built something real – now we need to grow it faster, smarter, and with more precision than a traditional engineering team can. We're looking for a Senior Growth Engineer to join a small, focused Marketplace team and own the full experiment loop – from hypothesis to code to result. You'll work closely with a PM and designer to run high-velocity tests, feed signal back to Google to sharpen our ad performance, and build the lightweight tooling that lets us learn faster than our competitors. This is a role for someone who ships first, learns fast, and doesn't look back. If you need things to be perfect before they go live, this probably isn't the right fit.

What does this role involve?

• Running end-to-end experiments across Lottie's marketplace, from ideation through implementation to result analysis.
• Building and optimising conversion-focused front-end experiences, often with limited design input.
• Writing code that sends performance data back to Google to improve ad targeting and campaign efficiency.
• Automating parts of our Google Ads configuration and campaign management.
• Owning A/B test pipelines and iterating quickly based on real usage data.
• Working autonomously within a lean, fast team.

What problems will you be solving?

• Turning traffic into outcomes. Our marketplace is trusted by half a million families a month. You'll be closing the gap between the families who land on Lottie and the ones who find the right care. Every experiment you run is a chance to make that faster, clearer, and more effective.
• Making our ad spend smarter. You'll build the pipelines and integrations that help Google understand what a good Lottie outcome looks like, so our campaigns optimise toward the things that actually matter.
• Moving fast in a space that matters. Care decisions are urgent and emotionally charged. Getting families to the right information faster isn't just a conversion metric. It's a meaningful outcome for real people.

We think you’ll be a great fit if…

• You have 5+ years of software engineering experience, front-end leaning with genuine full-stack breadth.
• You think in experiments. You can articulate what moved because of your work, not just what you built.
• You're comfortable with throwaway work. When a test fails, you kill it and move on.
• You're autonomous and low-dependency. You thrive with a hypothesis and a deadline, not a detailed spec.
• You're data-driven. You define success before you build, and you look at the numbers before you declare a win.
• You can start soon and hit the ground running. Contracting experience is a plus, but we're open to people making the move.
• AI tools like Claude Code are already a big part of how you work, and you're hungry to get better at them.

Sound like you but not 100%? Apply anyway - we're looking for potential and passion, not perfect CV match!

This role isn’t for you if…

• You prefer depth over breadth and one big build over many small bets.
• You need clearly scoped requirements before you can move.
• You're looking for a team with lots of process and structure around you.
• Our mission to transform later life care doesn't resonate with you.

Lottie’s Interview Process: We're keeping this fast and light to match the contract, you could be starting within a couple of weeks.

• Intro call with our Talent Lead (20 min, remote).
• Engineering Manager interview (45 min, remote).
• Technical pairing session (1 hour, remote).

Candidate Experience: All candidates will be informed of their application status.