jimmy-job

A Jimmy Job is when you do something on the rush, in other words, an improvised thing. A more formal equivalent expression would be To do something on the run

In Sense8 Season 2 episode 3 when Sun was breaking out of prison Nomi and her friend Bug were trying to hack the system, then Nomi asked bug :

Nomi: Bug?
Bug: I got something. Bit of a jimmy-job