The first step was to provide a lot of information about yourself, your career and even high school grades. Then the second step (where I failed) was a technical assessment.
I applied online. The process took 2 weeks. I interviewed at Canonical (London, England) in Nov 2024
Interview
You have to jump through a lot of hoops, but at least they are somewhat focused on what your role will be. There was a diabolically hard programming task; you had 45 minutes to solve. They also had you write a dissertation about yourself and take the Thomas Aptitude Test. Don't take the Aptitude test without finding a site that has examples. I improved my speed and accuracy by practising questions before taking the test.
Interview questions [3]
Question 1
What about your personality and interests makes you a great potential member of this team?