Director Chemistry

About Proxima

Proxima is a frontier AI and data generation company discovering the next generation of proximity therapeutics by making protein interactions programmable. Our platform brings together foundation-model machine learning, a scalable data generation engine, and a partnership track record exceeding $5B in collaborations across the world’s leading biopharma and tech organizations. We’ve recently closed an oversubscribed $80M seed round with an elite group of VCs including DCVC, NVIDIA’s NVentures, AIX, Yosemite among others.

Neo-1 is our all-atom foundation model that combines state-of-the-art structure prediction and molecular generation in a single system. Neo-1 enables rapid exploration of chemical and structural space for high value, previously intractable targets, and in particular unlocks small molecule proximity therapeutics like molecular glues with AI for the first time.

In parallel, we are developing an advanced structural interactomics platform built on proprietary XLMS technology and our Boston lab equipped with next-generation mass spectrometry instrumentation. This platform produces proteome-scale maps of protein interactions and helps identify small molecules that modulate proximity. Together with Neo-1, it creates an integrated system capable of co-folding protein complexes while generating candidate small molecules to influence those interactions.

Proximity-based therapeutics represent one of the most promising frontiers in modern drug discovery with the potential to treat previously intractable diseases and target 'undruggable' proteins. Our technology combines proteome-scale structural data with state-of-the-art generative AI foundation models, and coupled with our talented team of scientists and engineers we are uniquely well-positioned to discover and develop a new class of medicines. Come join us!

The Role

• We are building out our chemistry function in Boston and hiring a Senior Chemist to drive the chemistry on our pipeline programs.

• You will own compound design and synthesis for a discovery program from hit identification through lead optimization, working shoulder to shoulder with our Boston biology team. You will also work directly with our ML scientists, pressure-testing what Neo-1 generates against what is actually synthesizable and actually worth making.

What You'll Do

• Own compound design and SAR strategy for a pipeline program, from hit identification through lead optimization

• Use structure to drive the chemistry: co-crystal structures, homology and docking models, and physics-based methods where they earn their keep

• Work at the chemistry/biology interface, interpreting pharmacology data directly and shaping what gets tested next

• Design synthetic routes and direct external synthesis, staying close to the chemistry and solving synthetic challenges

• Drive DMTA cycles alongside biology and DMPK, prioritizing compounds on potency, selectivity, and developability

• Solve real problems: potency, selectivity, permeability, metabolic stability, solubility, and property space beyond Rule of 5

• Pressure-test Neo-1's output for synthetic tractability and chemical relevance, and feed results back so the models improve

• Manage CRO chemistry end to end: scoping, route review, quality, timelines, cost

• Build data packages that support internal go/no-go calls and pharma partner deliverables

What We're Looking For

• PhD in organic chemistry

• Roughly 8-12 years of post-PhD experience in medicinal chemistry or chemical biology, with extensive synthetic chemistry experience

• Demonstrated structure-based drug design capability: you have used structures and models to make chemistry decisions that improved potency or selectivity

• Practical computational chemistry skills built through discovery work rather than from a purely computational background

• Biology fluency: you can read a pharmacology package, reason about late-stage pharmacology and translational implications, and hold your own with biologists

• Program experience on enzyme and/or receptor targets (GPCRs, nuclear receptors)

• Strong synthetic chemistry fundamentals and sound judgment on route design

• Experience directing CRO chemistry and holding external partners to high standards

• Comfortable in a small, fast, resource-constrained team where you own the chemistry end to end