BuildForever - San Francisco / New York

We’re a small team of creative builders crafting consumer products that feel personal, magical, and deeply human. We build for ourselves first, with the belief that what delights us will resonate with millions more. We imagine a new golden age of consumer software - crafted with heart, emotion, and taste. Small, inspired teams building things that feel lovingly made, purposeful, and joyful to use. If that sounds like your happy place, you’ll fit right in.

The Role

We’re looking for an ML / AI Engineer to help architect and build the intelligent foundation beneath our consumer products. This is a high-impact, high-ownership role on the founding engineering team - ideal for someone who loves both cutting-edge ML work and crafting magical user-facing experiences.

You’ll design and build the data pipelines, models, retrieval systems, and inference infrastructure powering features like categorization, summarization, enrichment, search, personalization, and assistant-like interactions. And you’ll work closely with design and product to make these experiences feel beautifully simple.

How you’ll contribute…

• Architect and build the ML + retrieval systems powering our core product experience.
• Design and evolve data pipelines that ingest, classify, enrich, and summarize large volumes of user data.
• Build scalable inference infrastructure for both real-time and batch systems.
• Lead model selection, fine-tuning, embeddings, RAG pipelines, evaluation frameworks, and quality measurements.
• Prototype quickly to explore new ML-powered product ideas, then harden what works.
• Apply judgment and taste to make complex AI systems feel intuitive and magical to the user.
• Collaborate tightly with product, design, and engineering to create features that feel alive and deeply useful.
• Lay the groundwork for ML excellence inside a small, senior team.

You will thrive here if you…

• Have deep experience building ML-powered products - LLMs, embeddings, RAG, ranking, classification, NLP, or retrieval systems.
• Care as much about product quality as model accuracy - you sweat the user-facing details.
• Love owning problems end-to-end, from data design to modeling to inference to user-visible polish.