About luna

luna is the world's first digital wellbeing companion for teenagers, starting with girls and non-binary teens - think of us like a digital big sister in your pocket.

We are the global teen app of choice when it comes to learning about health, body and wellbeing, no more looking at Dr Google, Social Media or wondering in silence.

We’re backed by some of the UK’s top investors (Octopus & Syndicate Room), CEOs & Angels, and have been featured in publications such as BBC, CNN, Techcrunch, Hello, Cosmopolitan, Grazia and more.

luna is live in over 170 countries, with 40k active users and a product teens and parents genuinely love. We’ve also partnered with some of the world’s leading health and fitness brands, including Adidas, Gymshark and Lil-Lets (and have a super exciting pipeline for 2026!).

We're female-founded, mission-driven, and looking for a Senior Engineer to join our incredible team and shape what comes next.

What you'll do

• We have a live React Native app on Firebase/GCP with 40k monthly active users. What we need now is velocity and the ability to run experiments fast, learn from data, and iterate toward product-market fit.
• You'll own the technical side: building the infrastructure to ship and measure experiments weekly, not monthly. You'll shape how we use AI as the product evolves. You'll mentor our mid-level engineer and build engineering culture from the ground up.
• You'll work side-by-side with our founders, supported by our fractional CTO, on the decisions that shape the product.
• This isn't a role where you inherit a team and maintain what exists. It's a role where you build and define what comes next.

What we're looking for

• React Native expertise. You've shipped production apps and understand RN architecture deeply.
• Backend fluency. You can own and evolve Firebase/GCP infrastructure. Cloud Functions, Firestore, Auth - you understand how to build systems that are reliable, observable, and secure.
• Product instinct. You care about our members. You push back on specs that don't make sense and propose better solutions.
• Mentorship mindset. You enjoy helping other engineers grow. You're someone who pairs generously, gives feedback that teaches, and gets satisfaction from watching another engineer level up.
• Ambition: You want to build the number 1 app for teens and you have the drive and grit to make this happen; you’re not afraid to think big.
• No-nonsense approach: You get things done and you’re not afraid to roll up your sleeves.