Principal Scientist, Protein Design

The Role

Moderna is seeking an individual to provide technical leadership for in vitro selection and cell-surface screening of viral and bacterial antigens. This role will lead the design, execution, and continuous advancement of high-throughput mammalian cell–based screening platforms that interrogate broadly applicable design principles for glycoprotein antigens, enabling antigen optimization, improved expression and durability across multiple programs, and rapid maturation of computationally designed candidates.

Moderna is seeking an individual to provide technical leadership for in vitro selection and cell-surface screening of viral and bacterial antigens. This role will lead the design, execution, and continuous advancement of high-throughput mammalian cell–based screening platforms that interrogate broadly applicable design principles for glycoprotein antigens, enabling antigen optimization, improved expression and durability across multiple programs, and rapid maturation of computationally designed candidates.

The perfect candidate will provide technical leadership through direct involvement in the design and execution of complex in vitro selection campaigns, setting experimental strategy and partnering closely with computational protein design teams to ensure designs are evaluated and refined  addition to antigen-focused efforts, this individual will be cross-trained to support screening of de neo designed proteins, including mini binders and VHHs, as a shared discovery resource.

This role is intended for a scientist ready to own and evolve a core discovery capability, led by scientific judgment and execution, and shape in vitro selection integrates with AI- and structure-guided design across Moderna’s pipeline.

The candidate in this position will work closely with and report to the Senior Director, Computational Design and In Vitro Selection, and will also work closely with the VP, Protein Design, as well as other members of Research, to advance novel candidates to the clinic, drive exploratory trials to inform the generation of improved vaccine antigens and explore new concepts for mRNA medicines.

• Lead execution of in vitro selection and cell-surface screening campaigns, providing technical leadership through direct involvement in experimental design and execution.
• Design and run high-throughput mammalian display campaigns for complex, multimeric glycoproteins.
• Build and deploy scalable screening systems that replace resource-intensive plate-based assays.
• Develop and operationalize advanced in vitro selection and directed-evolution capabilities, including novel selection pressures and expanded mammalian display modalities.
• Serve as a key experimental partner to computational protein design teams, generating high-quality datasets and actionable design feedback.
• Provide technical mentorship and scientific guidance to other scientists.
• Represent in vitro selection capabilities in cross-functional discovery and platform discussions.
• Mentor and technically guide junior scientists to elevate overall design quality.

• PhD in Immunology, Molecular Biology, Biochemistry, Protein Engineering, or a related field.
• 5+ years of post-PhD industry or equivalent experience leading in vitro selection, mammalian cell-surface display, or directed-evolution efforts.
• Demonstrated ability to drive complex screening campaigns end-to-end.
• Deep expertise in mammalian display systems, high-throughput selection strategies, and experimental assay design.
• Strong working knowledge of computational, structure-based, or AI-driven protein design workflows.
• Scientific independence, judgment, and ownership consistent with a Principal Scientist role.

• Expertise with glycoprotein antigen expression and engineering (e.g., strategies around folding, trafficking, cleavage, stability, and glycan impacts).
• Strong capabilities in library design and construction (site-saturation, combinatorial, error-prone, DNA assembly), plus NGS-based readouts and quantitative enrichment analysis.
• A desire to make an impact…