Drug Discovery Scientist - PhD

Obsidian; San Francisco (CA); On-site; USD 90,000 - 150,000; Part time

Job summary

Obsidian is seeking a part-time researcher to design evaluation challenges for frontier AI in drug discovery. You will build data rooms grounded in real sources, craft grading rubrics, and validate approaches to ensure defensible conclusions.

The role emphasizes rigorous reasoning quality and the ability to set up complex, traceable datasets. Minimum 20 hours per week with flexible scheduling, in a browser-based studio using Claude Code/Claude Max.

Qualifications

• PhD or equivalent industry track record in mechanistic enzymology or structure-based medicinal chemistry.
• Ability to design defensible research problems that resist shortcutting.
• Experience judging reasoning quality, not just final answers.

Responsibilities

• Design the challenge — identify the hidden basin and forcing chain that makes one conclusion inevitable.
• Build the world — assemble a data room from real, source-grounded data. Every decisive value traces to a real source.
• Write the grader — a grading document that scores a submitted memo on substance, not style or method.
• Validate it — run verification and calibration before submission.
• Revise it — you own the rework if a reviewer requests changes.

Skills

Enzymology expertise

Structure-guided design

Fragment-based discovery

Medicinal chemistry

Education

PhD or equivalent

Tools

Claude Code

Claude Max

Job description

About the role

This is an evaluation framework for frontier AI models in drug research and development. Domain experts write realistic research problems wrapped around messy evidence worlds. The model works offline in a sandbox with open-source scientific tooling, receiving incomplete, indirect and sometimes misleading data, and must reach a defensible conclusion. The answer is present in the evidence but never stated.

Your job is to build a research problem so realistic and well-constructed that the model has to genuinely reason to solve it — it can't pattern-match or look the answer up.

What you'll deliver

1. Design the challenge — identify the hidden basin and the forcing chain that makes one conclusion inevitable.


2. Build the world — assemble a data room from real, source-grounded data. Every decisive value traces to a real source.


3. Write the grader — a grading document that scores a submitted memo on substance, not style or method.


4. Validate it — run verification and calibration before submission.


5. Revise it — you own the rework if a reviewer requests changes.

You are the final authority on every scientific and difficulty question in your task.

Who we're looking for

• Working expertise in mechanistic enzymology, structure-guided peptide or antibody design, fragment-based discovery, or structure-based medicinal chemistry — PhD or equivalent industry track record.


• You can pose a problem whose answer you can defend rigorously, but which a strong solver cannot shortcut.


• Comfortable judging reasoning quality, not just final answers.

Commitment

Minimum 20 hours per week, up to 40.

Tooling

Work happens in a browser-based studio plus Claude Code. A Claude Max subscription is required and is fully reimbursed.