Chao Sun


I am a Software Engineer working at Uber, mainly in distributed systems and databases. Especially, I am working on how to efficiently access and process the vast amount of data at Uber, which is critical to its business. Previously, I was an engineer at Cloudera, where I worked on Hive on Spark and RecordService. I am also a Hive committer and PMC member.

Even before that, I was a PhD student at University of Wisconsin-Milwaukee, with focus on type system and mechanized proofs for Java-like object oriented programming languages. For my thesis, I designed a lightweight type system based on Fractional Permissions, and proved its correctness with Twelf. Basically, this type system can be used to check nonnull-ness, unique-ness, and method effects. The novelty of the proof is that we piggy-back it to the existing proof for the Fractional Permission system, which is already proven sound by my advisor, John Boyland.

During my PhD period, I developed a strong interest on programming languages, especially in functional languages. I especially like Haskell.