David Allsopp’s twin existence as a countertenor of moderate renown and computer scientist began in 2000. He was a choral scholar at King’s College, Cambridge, spending four years in the world-famous choir while also studying computer science at the, um, world-famous computer laboratory.

After graduating, thinking that pursuing a career in technology was perhaps too obvious, or perhaps not really thinking at all, he decided to fund a tiny technology start-up on the salary of lay clerk at Westminster Cathedral. This led to a series of not-entirely-finished, but also not-entirely-dysfunctional, computer systems, mainly written in OCaml, alongside many recordings and concert performances all over Europe, and occasionally further afield.

In late 2016, David joined OCaml Labs in the Systems Research Group at Cambridge, with an initial brief to complete a Windows port of OCaml’s package manager, OPAM, which he had prototyped on a transatlantic flight returning from a series of performances celebrating 800 years of Magna Carta for, amongst others, the justices of the U.S. Supreme Court. It turned out prototyping was somewhat faster than delivering and, with a few distractions from the Multicore OCaml project and the Dune build system (and a spinning out of OCaml Labs into Tarides), it took a bit more than six months to deliver. David made a brief return to the Computer Laboratory in 2025 as part of the Energy and Environment Group and as a Tarides Fellow. He is now a software engineer at Jane Street, where he continues to get to work on the OCaml compiler.

This blog contains various bits of the technical part of David’s journey so far. Views expressed are his own, which is to say that things which make you happy may be associated with employers past and present; things which make you sad should certainly not be associated with employers past or most especially present and may be politely directed towards @dra27.uk or impolitely directed towards /dev/null.