Here’s what we know from our student body on what worked for them. This is not official advice. These are simply compiled anonymized quotes from other grad students sharing their experiences on different Slack channels.

PhD students are considered to still be pursuing their studies during the summer, so wouldn't be able to work full time on a student visa …. I told my hiring company that I would need help obtaining a visa and they were incredibly helpful. I was able to speak with an immigration lawyer (on DeepMind's dime) about my situation and ultimately they applied for a visa on my behalf which could only be obtained with employer sponsorship. The visa will allow me to simultaneously hold a 40hr temporary work visa and my study permit (so I shouldn't lose PGWP eligibility).

You should apply for a work permit, but since our program does not require us to do a co-op, you cannot get a formal letter to upload in your work permit application. With that being said, you can talk to your supervisor to write you a letter with a signature that the position you’ve found is “suitable” for your thesis. Then you can upload this letter instead of the formal one. It worked for me, as well as many others…