The role

You will join Rivercell's team as a Senior Machine Learning Scientist, contributing to our work on AI virtual cells. You will develop and evaluate models, contribute to the technical roadmap, and work with colleagues on research and implementation.

The challenge

We believe the AI virtual cell, a world model that can predict how cells will respond before an experiment runs, is the biology challenge of our times. Rivercell's cell-on-a-chip technology offers the opportunity to develop models alongside the platform generating their training data. You will work with our biology and engineering teams to explore which experiments, data, and architectures make those predictions more reliable. Our goal is to make biological research faster and more predictive, with models that help researchers decide what to test next.

• Implement, train, and test AI virtual cell models.

• Contribute to the technical roadmap and research priorities through literature reviews and experimental findings.

• Identify and harmonize useful cellular datasets with the biology team

• Develop benchmarks and evaluation tools relevant to industrial users.

• Maintain reproducible training code and analyses for the team and external collaborators.

• Debug data pipelines and improve model performance and compute efficiency with engineering colleagues.

• Contribute to preprints / publications, conference publications, and public benchmark releases.

• Present findings and help respond to questions from reviewers and collaborators.

• Support technical material for partners and fundraising.

• Opportunity to work on a cutting-edge project in techbio

• Opportunity to join an ambitious team and impactful startup among the first employees

• Competitive salary and equity package

• Exciting opportunities for personal and professional growth within the team

• You have a PhD in machine learning, computational biology, or an adjacent field, or equivalent industry research experience

• You have hands-on experience training models on single-cell or perturbation data

• You have at least one first-author publication in a relevant venue (Nature Methods / Cell Methods family, NeurIPS / ICLR / ICML main track or workshop, or a preprint with demonstrable adoption in the field)

• You have strong PyTorch fluency, including distributed training on multi-GPU or multi-node setups

• You are comfortable with the single-cell data engineering ecosystem and its real-world messiness

• You have strong engineering practices: versioned data, pinned dependencies, reproducible analyses, documented decisions

• You have strong scientific communication skills, written and spoken: write papers, present results to AI-lab and pharma audiences, and translate technical claims into investor-facing material

• You have a make-it-work-make-it-better mentality: comfortable shipping the first version end-to-end on a pre-seed timeline, choosing pragmatism over elegance, and returning to harden the parts that proved load-bearing

Please let us know in your application if you specifically have experience with one or several of the following:

• Experience with transformer or diffusion architectures applied to cellular data

• Foundation-model pretraining, fine-tuning, or evaluation at scale

• Familiarity with cellular morphology and image-feature pipelines

• Benchmark design experience, including a sense of the politics of running a public leaderboard

• Working knowledge of the current AI virtual cell literature and an opinion about where it is going

• Experience in working in a fast-paced start-up environment

Throughout the recruiting process, you will meet 4 to 6 team members of Rivercell.

1. Introductory call (up to 30mn, videocall)

2. Technical interview (up to 90mn)

3. Performance interview (up to 90mn, in person)

4. Culture interview (up to 60mn, in person)