Member of Technical Staff

Slingshot AI; Greater London; On-site; GBP 120,000 - 180,000; Full time

Benefits offered by this job

Competitive pay

Equity

Travel between NYC and London offices

Office perks: lunch & coffee

Job summary

Slingshot AI is building Ash—the first AI designed for mental health—and seeks a Member of Technical Staff in ML to ship end-to-end models, training infra, harnesses, and evals. You will join a small, highly capable team and own the quality and impact of features—driving real-world outcomes for users and lives.

The role emphasizes hands-on engineering, learning mindset, and collaboration across ML, product, and operations, with offices in London and NYC.

Qualifications

• 3+ years engineering experience shipping production systems.
• Experience with LLMs, fine-tuning, harness engineering, and evals.
• Owns the end-to-end delivery of features and models.
• Thrives in a fast-paced startup environment and values collaboration.

Responsibilities

• Ship models, training infrastructure, harnesses, and evals end-to-end.
• Design, build, and launch ML tech that differentiates Ash for mental health.
• Own value delivery to users and improve production performance.
• Collaborate with a small, highly skilled team and care deeply about code quality.

Skills

LLMs experience

Fine-tuning

Eval loops

Ownership mindset

Tools

SkyPilot GPUs

gRPC

Kubernetes

GCP

Next.js/TypeScript

Rust

Dart/Flutter

Job description

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.

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.

The role

As a Member of Technical Staff focused on Machine Learning, you will ship models, training infrastructure, harnesses and evals end-to-end: designing, building, and launching the tech that makes Ash differentiated as a specialized model for mental health, to change a billion minds and lives.

As a core member of a small but highly skilled team, we expect you to act as an owner and to care passionately about delivering value to our users and ultimately to make people's lives better. We are looking for builders who care deeply about the quality of their work and want to ship things that make a real difference in people's lives. We care more about how you think and build than your specific background. If you're a great engineer who's curious about ML, we'd love to hear from you.

We work on a model-agnostic post-training engine running on our own cluster of leased GPUs managed by SkyPilot, trained by an auto-research loop, and evaluated with our home-grown eval index aimed specifically at mental health. We’re constantly improving, and focus on building feedback loops over features, and constantly learning from our production performance, our psych research team, and scalable data sources. Our product tech stack uses Dart/Flutter for the app, Kotlin for core backend services, and Next.js/TypeScript for internal tooling, as well as Rust for low level media streaming. We use gRPC and GCP (Kubernetes, Cloud Run) as our primary cloud provider. You're not required to be an expert in all of these tools, but we would like you to come with a learning mindset and to not be afraid of getting your hands dirty with whatever tool the job might require.

About you

• 3+ years of engineering experience, owning systems other people rely on.

• Experience working with LLMs, ideally with fine-tuning, harness engineering, and evals

• Proficient in using agents to do your homework for you

• Driven by creating a world-class product with a world-class team, want to own what you build, and you're happy tearing down experiments and features as we learn

• Experience in a fast-paced startup, or the drive to thrive in one.

• Collaborative and direct. You enjoy working in person with a small team.

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) and meaningful equity

• Travel between our NYC and London offices

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

• We cover your personal therapy