Principal Scientist​/Associate Director, Developability & Protein Sciences

About Cartography Biosciences

Cartography Biosciences is advancing a differentiated oncology pipeline of antibody-based therapies designed to target tumors with unprecedented precision. The company’s ATLAS and SUMMIT discovery platforms are powered by an industry-leading, fully integrated dataset spanning hundreds of thousands of cell states across healthy tissues alongside large-scale single-cell profiling of patient tumors. By combining petabyte-scale proprietary data, machine learning, and AI-driven biological insights, Cartography is identifying highly specific tumor targets and logic-gated target combinations to generate therapies engineered for maximal tumor selectivity and meaningful patient impact.

The company’s lead program, CBI-1214, is a T-cell engager in development for colorectal cancer. CBI-1214 entered the clinic in early 2026 and is currently enrolling and treating patients in a phase 1 trial.

About the Role

We are looking for a Principal Scientist or Associate Director to lead develop ability and protein sciences for our bispecific and multispecific antibody programs, including T-cell engagers. You will own the biophysical and develop ability screening that informs lead selection, along with the expression and purification that supplies it, working in house and with external partners. You will manage and grow a small team of scientists and play a leading role on cross-functional therapeutic program teams.

This is a hands-on, hybrid role based onsite in South San Francisco, with roughly half of your time at the bench alongside the team. You will turn develop ability data into program decisions and work with Antibody Engineering, Pharmacology, and program leadership to act on them. We expect the scope of the role to grow with the team and the pipeline.

Key Responsibilities

Develop ability & Biophysical Characterization

• Deliver develop ability and biophysical data for therapeutic programs as candidates advance from hit screening through lead optimization to development candidate nomination.
• Own the develop ability screening cascade, including thermal stability (e.g. DSF, DSC), aggregation (e.g. analytical SEC), self-association (e.g. AC-SINS, DLS), charge variants (e.g. IEX, cIEF), hydrophobicity (e.g. HIC), polyspecificity (e.g. BVP ELISA, PSR), and molecular integrity (e.g. intact mass, CE-SDS).
• Integrate in silico biophysical property assessment (e.g. sequence liabilities, surface patch analysis, aggregation propensity) with experimental data to prioritize and engineer candidates.
• Characterize advanced leads and development candidates in depth through stress and forced degradation studies, PTM mapping (e.g. peptide mapping LC-MS), and early formulation development.
• Help define and own the develop ability criteria at each program decision gate, and apply them consistently across programs.
• Expand the throughput, robustness, and technical scope of our protein analytics capabilities to support AI/ML-driven antibody engineering.
• Oversee research-stage protein production from 1 mL to 10 L scale, in house and through external partners, run as a service with clear intake, prioritization, turnaround, and quality acceptance of incoming material.
• Optimize transient production of multi-chain bispecific and multispecific assemblies (knob-into-hole heterodimers, VHH-containing trispecifics), including plasmid chain-ratio tuning to maximize correctly assembled product.
• Direct purification strategies that resolve bispecific product-related species from the correctly paired heterodimer, using Protein A capture with ion exchange, hydrophobic interaction, mixed-mode, and preparative size-exclusion polishing.
• Scale plate-based…