Russ Yanofsky is an engineer at Chaincode Labs. His main body of work in Bitcoin Core is the separation of the node, wallet and graphical interface components, which sound like tidying and are not.
Bitcoin Core began as one program in which the wallet, the validating node and the user interface shared memory and internal calls. Yanofsky's work introduced well-defined interfaces between node and wallet and between node and GUI, and those interfaces have been merged. The longer-term goal he continues to work towards is running the components as separate processes, so that a bug in the interface cannot reach the keys and a node operator can run validation without the wallet code loaded at all.
Before Chaincode he worked on web search at Google and on set-top video software at Videon Central, Inc.