ThroughLine is the global safety net for people in crisis, helping millions access verified crisis support resources and guided self-help on the world's largest platforms – ChatGPT, Google, Pinterest, Roblox, Tinder – just to name a few.

We're solving some of the hardest problems at the intersection of mental health, AI, and global scale. That means working alongside a team of engineers, clinicians and operators who care deeply about getting this right, where the stakes are real and the work matters.

We move fast and we trust our people. You'll have real autonomy and responsibility from day one. You'll be part of a team that's genuinely diverse because the people we serve are genuinely diverse. We're building ThroughLine to reflect that.

The Role

We're looking for a Full Stack Engineer—part hacker, part researcher, part builder. Someone who thrives in ambiguity and can span front-end, back-end, and AI systems. You want to set the global benchmark for AI safety in mental health.

Why this role exists

Our AI care navigation platform guides users in distress through natural conversation, understanding their needs and connecting them to the right next step. It's embedded in customer products dealing with mental health, online safety, and crisis support.

We're moving from validated prototype to scalable infrastructure. You'll join at the point where AI safety engineering, product experimentation, and ethical system design converge.

We need someone who can navigate that intersection fluently—shipping fast without compromising on safety.

What you'll do

• Engineer for safety: design, test, and monitor guardrails for LLMs and classifiers.
• Instrument and evaluate model behaviour via our internal platform — your code helps train the next iteration.
• Work fluidly across research, front-end, and back-end (we value capability over titles).
• Ship features that matter. You'll see your code in production, helping people in distress every day.
• Stay close enough to the product to understand how safety decisions cascade through the system.

What this isn’t…

• Deep-learning research. We're not publishing papers or running experiments for their own sake.
• Everything ships.
• Waiting for perfect specs. You'll work with incomplete information and incomplete specs. You iterate.
• Pure infrastructure work. You're not optimizing for elegance; you're optimizing for outcomes that matter.

What You’ll Bring

• Versatile engineer. Comfortable shifting between research, API design, and UI; strong foundations in data structures, concurrency, and model behaviour.
• LLM-native. You integrate GPT, Gemini, Claude, or open models into your workflow; prompts and embeddings are second nature.
• Founder / CTO mindset. You’ve built or led something from scratch and owned it end-to-end.
• Bias toward action. You’ve migrated, switched careers, or pivoted under pressure — and thrived.
• Hacker mentality. You care more about outcomes than abstractions; you make it work, then make it safe.
• Mission-aligned. You believe technology should reduce suffering — not exploit it.

Technical context
Our stack (for orientation): React, Next.js, TypeScript, Tailwind (frontend); Node.js, Python (backend); Google Cloud Run, Pub/Sub, Vercel (infra); GPT, Gemini, Claude, open-weight models (AI)

Wishlist / Bonus experience

• Vector search, embedding pipelines (Chroma, Pinecone, Weaviate)
• Agentic context-engineering / LLM orchestration (LangGraph, CrewAI, Transformers Agents, AutoGen)
• Retrieval-augmented generation / structured prompting / prompt-chaining
• Multi-model fine-tuning (OpenPipe, Weights & Biases, Hugging Face)
• Synthetic-data pipelines + LLM evaluation frameworks
• Secure dataflow / privacy-by-design in health or safety domains
• Early-stage startup or social-impact experience
• Open-source or hackathon projects

What success looks like in 90 days

• You’ve shipped a production-grade LLM feature that improves safety or accuracy.
• You’ve improved or rebuilt a key workflow for faster iteration.
• Your development rules become part of our engineering culture.
• You’ve advanced our AI-safety metrics — accuracy, latency, reliability.

What we offer
The best benefit: your team
You'll be joining a small, senior, cross-disciplinary team:

• A technical product leader who codes, with three startup exits
• A former AI startup CTO and Samsung researcher-engineer
• A clinical psychologist who codes in Python and thinks in systems

Our culture

• We've all experienced times when we needed help – that's why we care deeply about this work
• We bring perspectives shaped by gutsy choices – immigrating, founding companies, career pivots, living our identities openly.
• We move fast but sustainably (no burnout culture here)
• We're collaborative and non-hierarchical – good ideas matter more than tenure
• We listen in all moments, whether things are going well or not (and not just on work stuff)
• We work with care and urgency because people rely on us on their worst days
• We start every week with a genuine personal check-in and end on Fridays with a check-out with a rotating leader
• We're technology realists who believe human ingenuity should be focused on reducing suffering

You shouldn't choose us if…

We're not a fit for everyone – and that's okay.

• We're driven, really driven: Our mission is personal to us. If you're not passionate about doing things differently with mental health support, you might find it a bit much.
• We're small: We're early on our journey, so no specialized roles and no "that's not my job."
• We're a start-up: We're still figuring things out, which means incomplete information and unexpected changes.

At ThroughLine, we serve people across all genders, ethnicities, racial and religious backgrounds. We want our team to reflect this too. As an equal opportunity employer, we welcome all applicants. We especially encourage candidates from underrepresented communities to apply. If you think you have
what it takes, apply!