Dr. Leonard Apeltsin

Senior Director of Studies

Dr. Leonard Apeltsin is the Senior Data Scientist and Engineering Lead at Primer, a machine intelligence company based in San Francisco. Born in Ukraine, he immigrated to the U.S. as a child and grew up in the Philadelphia area. He completed undergrad degrees in biology and computer science at Carnegie Melon, then moved to the Bay Area to complete a Ph.D. in bioinformatics at UCSF.

Throughout his academic career, Dr. Apeltsin used his uniquely interdisciplinary skills to approach complex and challenging problems, typically involving vast amounts of data. His doctoral work focused on processing sequencing data from the human genome project, while his postdoctoral work uncovered a sequence biomarker in the bloodstream that could lead to a new diagnosis method for multiple sclerosis.

Following his postdoc, Dr. Apeltsin joined the small, early-stage startup that ultimately grew into Primer. In the years since, his work has primarily focused on natural languages and AI, notably resulting in a patent for automated summarization.

Dr. Apeltsin is also very interested in linguistics and multiple languages. His recent blog post on Russian Natural Language Processing went viral on the Primer website.



San Francisco, California


Primary Subjects:

  • Bioinformatics

  • Natural Language Processing

  • Data Science


  • English

  • Russian


  • Post-doctoral Research at UCSF, 2012-2014.

  • Ph.D. in Bioinformatives, UCSF, 2011.

  • Bachelors Degree in Biology and Computer Science, Carnegie Mellon University, 2005