---
title: 'Antibody Engineering at Chai Discovery'
canonical: 'https://feeny.ai/job/antibody-engineering-chai-discovery-san-francisco-781hbfm2bd46'
type: 'job'
last_seen: '2026-09-07'
---

# Antibody Engineering at Chai Discovery

- **Company:** Chai Discovery
- **Location:** San Francisco, CA
- **Employment:** full-time
- **Work type:** onsite
- **Posted:** 2026-02-15
- **Last confirmed live:** 2026-09-07
- **Apply:** https://jobs.ashbyhq.com/chaidiscovery/2de4c9cf-bb01-4997-b0c9-534e4fd2db7b

## Job description

## ABOUT CHAI DISCOVERY

Chai builds the design suite for molecules. We train frontier models that learn the underlying foundations of biochemical structure and interaction, so scientists can move faster and pursue targets that other methods cannot reach.

AI is reinventing life sciences the same way it reinvented software engineering, and Chai is at the forefront of this shift. Leading pharmaceutical companies like Eli Lilly https://endpoints.news/eli-lilly-chai-discovery-sign-ai-software-deal/, Pfizer https://www.forbes.com/sites/amyfeldman/2026/06/04/why-pfizer-and-eli-lilly-are-betting-on-this-13-billion-ai-drug-discovery-startup/, and Novartis https://www.chaidiscovery.com/news/novartis-partnership are adopting our platform to power their drug discovery programs.

We value diverse perspectives and are ready to find greatness in unexpected places.

## ABOUT THE ROLE

We are looking for exceptional antibody engineers and computational protein designers to help us evaluate, expand and apply the capabilities of our de novo antibody design models. You'll join an elite team of biologists, computational scientists and AI researchers.

Scientists at Chai are power users and test pilots of our AI platform. We probe the design space for novel targets and formats, validate in silico solutions for function in the lab, and distill empirical rules from the results. We execute experimental programs at scale that guide, train and evaluate next generation models, working closely with our AI research team. We partner with scientists from the world's leading pharma companies to push their discovery programs into new territory. I think you could be a good fit.

This is an opportunity to push the boundaries of applied biology and artificial intelligence. You'll get exposed to a wide array of scientific problems and research methods, far beyond what one encounters working on a single drug program or within a traditional life sciences company.

## ABOUT YOU

You have a deep desire to push the limits of what’s possible in therapeutic design, and a restless drive to solve real-world problems and iterate quickly. You are curious, high-agency and incredibly persistent.

- PhD or equivalent experience in the field—Antibody Engineering, Computational Biology, Protein Sciences.
- Hands-on experience with design and characterization of antibody-based biologics. Proficient in molecular-biology workflows, binding and developability assays, inspecting structures in PyMOL or similar tools.
- Track record of strong communication, collaboration and execution.

## WE OFFER

The opportunity to work at the vanguard of AI research and frontier biology, with world-class people, on a mission that matters. We protect & promote a culture of high velocity and ownership. We compensate our team accordingly.

## About Chai Discovery

## Company Overview
- **One-liner**: Chai Discovery builds frontier AI models to predict and reprogram the interactions between biochemical molecules, focusing on de novo antibody design for drug discovery.
- **Entity Type**: Private (Series B)
- **Headquarters**: San Francisco, California, United States
- **Founded**: 2024
- **Founders**: Joshua Meier, Jack Dent, Matthew McPartlon, Jacques Boitreaud

## Core Business
- **Primary industry**: AI-powered drug discovery and biotechnology
- **Target customers**: B2B — Large pharmaceutical and biotech companies (e.g., Eli Lilly)
- **Mission or purpose statement**: "Transforming biology from a scientific practice into an engineering discipline" [chaidiscovery.com](https://www.chaidiscovery.com/)

## Products & Services
- **Chai-2**: A frontier AI model designed for de novo antibody design. It can design antibodies against challenging targets with atomic precision, moving past simple binding toward real therapeutic viability. The company describes it as a "computer-aided design suite" for molecules. [techcrunch.com](https://techcrunch.com/2026/01/16/from-openais-offices-to-a-deal-with-eli-lilly-how-chai-discovery-became-one-of-the-flashiest-names-in-ai-drug-development/), [chaidiscovery.com](https://www.chaidiscovery.com/)

## Market Standing
- **Valuation/Market Cap**: $1.3 billion (as of December 2025 Series B) [linkedin.com](https://www.linkedin.com/company/chaidiscovery)
- **Key Metric**: Total funding of $231.0M across 6 rounds. Key rounds include: Seed ($30M, led by OpenAI and Thrive Capital, 2024), Series A ($70M, 2025), and Series B ($130M, led by General Catalyst and Oak HC/FT, Dec 2025). [linkedin.com](https://www.linkedin.com/company/chaidiscovery)
- **Notable Investors/Partners**: OpenAI, Thrive Capital, General Catalyst, Oak HC/FT, Amazon Web Services (non-equity assistance). Strategic partnership with **Eli Lilly** (announced Jan 2026) for drug development. [techcrunch.com](https://techcrunch.com/2026/01/16/from-openais-offices-to-a-deal-with-eli-lilly-how-chai-discovery-became-one-of-the-flashiest-names-in-ai-drug-development/)
- **Growth Signals**: Named to Endpoints News "11 most promising biotech companies of 2025" [linkedin.com](https://www.linkedin.com/company/chaidiscovery). Headcount grew **169.2% YoY** (approx. 27 employees) [linkedin.com](https://www.linkedin.com/company/chaidiscovery). LinkedIn followers grew **508.7% yearly** [linkedin.com](https://www.linkedin.com/company/chaidiscovery). The Eli Lilly deal is a major validation of the technology by a top-tier pharma company.

## Competitive Advantages
- **Custom, homegrown AI architecture**: Every line of code is proprietary; they do not fine-tune off-the-shelf LLMs, giving them a unique technical moat. [techcrunch.com](https://techcrunch.com/2026/01/16/from-openais-offices-to-a-deal-with-eli-lilly-how-chai-discovery-became-one-of-the-flashiest-names-in-ai-drug-development/)
- **Deep ties to OpenAI**: Founders built the company out of OpenAI's offices, with Sam Altman as an early supporter and OpenAI as a seed investor, providing significant credibility and talent access. [techcrunch.com](https://techcrunch.com/2026/01/16/from-openais-offices-to-a-deal-with-eli-lilly-how-chai-discovery-became-one-of-the-flashiest-names-in-ai-drug-development/)
- **Founder expertise**: Co-founder Joshua Meier previously developed ESM1, the first transformer protein-language model, at Facebook (Meta) and worked at Generate:Biomedicines, giving the team deep domain expertise. [techcrunch.com](https://techcrunch.com/2026/01/16/from-openais-offices-to-a-deal-with-eli-lilly-how-chai-discovery-became-one-of-the-flashiest-names-in-ai-drug-development/)
- **Early market traction**: Has already secured a partnership with Eli Lilly, a top-10 global pharma company, indicating strong commercial viability ahead of many competitors. [techcrunch.com](https://techcrunch.com/2026/01/16/from-openais-offices-to-a-deal-with-eli-lilly-how-chai-discovery-became-one-of-the-flashiest-names-in-ai-drug-development/)

## Strategic Focus
- **Deploy AI in real-world drug discovery**: The company's immediate priority is to embed its models into the workflows of pharma partners like Eli Lilly to accelerate the development of novel therapeutics.
- **Unlock new classes of medicines**: By enabling atomic-precision design of antibodies, Chai aims to target historically "undruggable" biological pathways.
- **Scale the platform**: Continue to improve the Chai-2 model and expand its capabilities, with a goal of seeing first-in-class medicines enter clinical trials by the end of 2027. [techcrunch.com](https://techcrunch.com/2026/01/16/from-openais-offices-to-a-deal-with-eli-lilly-how-chai-discovery-became-one-of-the-flashiest-names-in-ai-drug-development/)

## Why Work Here
- **Culture**: Highly interdisciplinary, blending computer science, engineering, biology, chemistry, and physics. The company values deep technical talent and a "heads down" approach to pushing the frontier of AI. [chaidiscovery.com](https://www.chaidiscovery.com/careers)
- **Work policy**: In-person in **San Francisco, California** (HQ at 235 Pine St, Suite 1300). [linkedin.com](https://www.linkedin.com/company/chaidiscovery)
- **Notable perks/engineering culture**: Working at a well-funded, high-valuation startup with direct ties to OpenAI and a clear path to impact in a cutting-edge field. The team is small (~27 people) but growing fast, offering significant ownership and responsibility. Talent sources include Stripe, CERN, and Generate:Biomedicines, indicating a high-caliber peer group. [linkedin.com](https://www.linkedin.com/company/chaidiscovery)

## Sources
1. [Chai Discovery Website](https://www.chaidiscovery.com/)
2. [Chai Discovery Careers Page](https://jobs.ashbyhq.com/chaidiscovery)
3. [TechCrunch - How Chai Discovery became one of the flashiest names in AI drug development](https://techcrunch.com/2026/01/16/from-openais-offices-to-a-deal-with-eli-lilly-how-chai-discovery-became-one-of-the-flashiest-names-in-ai-drug-development/)
4. [LinkedIn - Chai Discovery Company Page](https://www.linkedin.com/company/chaidiscovery)

## Other roles at Chai Discovery

- [First Finance Hire](https://feeny.ai/job/first-finance-hire-chai-discovery-san-francisco-h4sy4s08eqwy) — San Francisco, CA
- [Scientist, Protein Design](https://feeny.ai/job/scientist-protein-design-chai-discovery-san-francisco-11g6bx8mhvx5) — San Francisco, CA
- [Internship](https://feeny.ai/job/internship-chai-discovery-san-francisco-web8x5z637y7) — San Francisco, CA
- [Security Lead](https://feeny.ai/job/security-lead-chai-discovery-san-francisco-ff3e5ja76ac2) — San Francisco, CA
- [Data Ops](https://feeny.ai/job/data-ops-chai-discovery-san-francisco-tt1g0j189zc0) — San Francisco, CA
- [Research Scientist](https://feeny.ai/job/research-scientist-chai-discovery-san-francisco-x8yhz96d2xxn) — San Francisco, CA
- [Forward-Deployed Scientist](https://feeny.ai/job/forward-deployed-scientist-chai-discovery-san-francisco-gmjhzbwc2zg3) — San Francisco, CA
- [Engagement Management](https://feeny.ai/job/engagement-management-chai-discovery-san-francisco-acqdvmn9f6qy) — San Francisco, CA
- [Business Development](https://feeny.ai/job/business-development-chai-discovery-san-francisco-5yy85rvtqh62) — San Francisco, CA
- [Talent](https://feeny.ai/job/talent-chai-discovery-san-francisco-pdhh1fnjkwwx) — San Francisco, CA