Russell became interested in Bitcoin in 2011. He explored the Bitcoin protocol by writing a validating node in Haskell. Along the way he discovered how to use compact public keys and the CVE-2012-1909 vulnerability in the protocol. Outside of Bitcoin, Russell is known for developing the technology behind lenses and traversals in Haskell. Russell earned his Ph.D. cum laude from Radboud University for his work developing computer verified formal proofs. He was part of the team at the Microsoft Research Inria Joint Centre that completed a computer checked proof of the Feit–Thompson theorem.