Senior Software Engineer

Slingshot AI

Slingshot AI is the team behind Ash, the first AI designed for mental health. Our mission is to make support more accessible and help people change their lives in the ways they want.

We’re building a world-class team by empowering individuals with the autonomy, flexibility, and support they need to do their best work. We dream big, iterate fast, and care deeply. If that sounds like you, we’d love to hear from you.

Our team spans machine learning, product, engineering, conversational design, clinical, growth, and operations, with offices in both New York City and London.

We're a well-funded Series A company, having raised $93M from Andreessen Horowitz, Radical Ventures, Forerunner Ventures, plus top-tier tech investors involved in ElevenLabs, Captions, Shopify, Plaid, Notion, Canva, Twitch, Airtable, and many others.

Senior Software Engineer

We are hiring an entrepreneurial and output driven Senior Software Engineer, to join our experienced and ambitious technical team. Reporting to our Engineering Manager, you will work on the front-end and back-end systems that drive Ash’s ability to feel personal, timely and human to users. This person will be an owner of their domain, developing and deploying products 0-1 with little oversight. You will be a core member of a team building a once in a generation product that will eventually serve 1 billion users.

If you are technically obsessed, care deeply about shipping products that matter most in a world of AI, and want to produce and deploy best in class code with a team driven by impact and outcomes, this role could be for you.

Key responsibilities:

• Build and own the systems that make Ash feel personal, timely, and human — including memory architecture (what Ash saves, retrieves, and forgets), notification logic (what to send, when, and why), conversation delivery (how messages are timed, split, and surfaced to users), and personalisation features that adapt to each user over time.

• Work across the full stack — primarily in Python within our ML codebase and Kotlin for core backend services, extending into Dart/Flutter for app features and Next.js/TypeScript for internal tooling where needed.

• Collaborate closely with our ML Lead, designer, and product team to take features from idea to production quickly — nothing should take more than a few days to get to an early working version.

• Own the full product development lifecycle; first lines of code to deploying, monitoring, and iterating in production.

• Rapidly investigate, diagnose, and resolve bugs to ensure product stability.

• Drive features from insight to production independently — from identifying the problem to shipping the solution.

About you:

• 8+ years of full stack experience across multiple startups and/or intense high growth environments

• Live in London, UK and want to work out of an office with a team

• Thrive working across the full stack, with a strong back-end foundation and comfort working within ML codebases. Experience with frontend and mobile is a plus but not the primary focus.

What we offer:

• A chance to join a passionate tight-knit team working on something to change the world

• Competitive compensation (top of personal market)

• Travel between our NYC / London offices

• Usual startup perks like free lunch and coffee in office + generous learning budget

• We cover your personal therapy