
Founding AI Engineer
San Francisco, CA at a glance
- Rent
- #2 of 51$2,680/mo+46% vs US avg
- Weather
- #17 of 51295 mild days0 hot · 0 cold
- Income tax
- #1 of 5113.3% top rateCalifornia
What you need
- Strong backend engineering and production system experience
- Hands-on AI app building: context, retrieval, tool use
- Develop ML models from data to production
- Python, SQL, and cloud infrastructure fluency
What you'll do
- Build AI harness for agent context and tool use
- Create evaluation datasets, benchmarks, and feedback loops
- Design, train, and deploy ML models for coaching
- Develop production backend and data pipelines
About Us
Coach is building the AI coach for the physical world. Starting with in-person sales.
For centuries, field organizations have relied on layers of management to relay information, coach teams, and understand performance. We believe AI will radically change how these companies operate and how people learn and improve at work.
Today, understanding why a sales rep succeeds or struggles still requires being alongside them in the field. That doesn’t scale.
Coach helps employees learn faster, improve, and close more. Managers get a clear view of what’s happening, where people need help, and why, so they can focus on solving problems.
Our custom AI harness turns field conversations and business context into sales intelligence, grounding coaching in what actually happens on the ground. Over time, that accumulated knowledge becomes a company brain: a shared understanding of how the business works.
What you’ll own
- Our AI harness. Build how agents gather context, access tools, retain knowledge, deliver and track coaching grounded in real conversations.
- Evaluation and experimentation. Create datasets, benchmarks, and feedback loops to measure agent and model quality. Investigate failures, challenge apparent patterns, and test whether improvements translate into customer value.
- Machine learning models. Design, train, evaluate, and deploy models for behavioral analysis, performance forecasting, and personalized coaching from dataset construction and feature engineering to validation and monitoring.
- Production infrastructure. Build and operate the backend, data pipelines, and services behind Coach. Improve reliability, security, observability, latency, and cost.
- Our software factory. Work with the team to build the tools, environments, and verification workflows that let our team and coding agents collaborate effectively.
- Forward deploying. You will meet our customers and spend time with them to better understand how to satisfy their needs
Who you’ll work with
We're a small team in SF and Paris, growing fast. Our CTO has been building software and AI across many industries for the last 10 years. Our CEO and COO are repeat founders who built and ran in-person sales teams selling to pharmacies. We've lived the problem firsthand and built Coach to solve it.
With just two employees (Customer Success + Engineering), we took Coach to $1.5M ARR in 8 months — and we're scaling aggressively from here.
What you bring
- Strong backend engineering skills and experience shipping and operating production systems.
- Hands-on experience building AI applications: context management, retrieval, tool use, orchestration, and evaluation.
- Experience developing ML models on real data and taking them beyond experimentation into a usable product.
- Solid foundations in probability, statistics, and machine learning. You can recognize confounding, prevent data leakage, quantify uncertainty, and choose an appropriate baseline.
- Fluency in Python and SQL, and confidence working with cloud infrastructure.
- An AI-native approach to development, with the judgment to understand and verify what your tools produce.
- Curiosity about the people using your work, and the ability to turn an ambiguous business problem into a focused implementation.
We're not hiring for a title or a number of years. We're hiring for what you can build. Whether you've done this for 2 years or 10, if you've shipped real AI systems into production and can turn an ambiguous business problem into a working product, we want to talk.
Our current stack
- Backend: Python, FastAPI, Pydantic.
- Agent systems: a custom harness built with PydanticAI and frontier model APIs.
- Data: PostgreSQL and Supabase.
- Infrastructure: Google Cloud Run, Cloud Tasks, Docker, and GitHub Actions.
- AI evaluation and observability: Braintrust.
- Voice: LiveKit, Deepgram, and ElevenLabs.
You’ll help evolve this stack and select the modeling tools that fit the problems we tackle. We value strong foundations and evidence of what you’ve built; experience with every tool listed isn’t required.
SF-based, relocation supported (visa sponsorship available)
Interview Process
Our process has four stages, mostly remote:
- Intro conversation with our CTO. Discuss your experience, what you’re looking for, and the technical challenges we’re tackling at Coach.
- A short, time-boxed take-home exercise. Work through a problem representative of the role. AI tools are welcome and encouraged, that’s how we work.
- Technical deep dive. Walk us through your solution, explain your decisions and trade-offs, and explore a small extension together. We care about how you think, build, and verify your work.
- Meet the cofounders and team. Discuss how we’d work together, hear more about our ambition, and ask your remaining questions.
Throughout the process, we want you to get a clear sense of the work, the team, and the opportunity.
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About COACH
Coach is the AI sales coach for in-person sales teams. Reps record every meeting, and our AI figures out what your best closers do differently, then coaches everyone else to do the same, with precise, personalized feedback after every meeting. Managers finally see 100% of what happens in the field: Coach flags who's stuck and why, so they only step in when it matters, and can coach 5× more reps. And every meeting feeds one sales brain, so leadership finally gets answers to the questions that used to be guesswork. They finally see the game of their team not just the scoreboard. Our bet: in the AI era, in-person sales will only matter more. It may end up being one of the last truly human jobs. Our conviction: any motivated rep can become a great one, meeting after meeting. The results so far: +32% average lift in conversion rate. COΛCH, post-game video analysis for field sales reps. YC S26
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