Interview pipeline took approx 1 month. Initial call with HR, technical discussion with hiring manager, troubleshooting w/ Linux, coding, finally talk with the director. Although coding round was done with a Backend Engineer rather than an SRE, it was still fun. The team is kind and technical interviews allow you to share your experiences and think outside the box. It is evident they apply a healthier SRE culture here. Unfortunately, offer did not meet my expectations - should the circumstances meet in the future, I would definitely join. It seems growing fast with their users expanding and their mission requires applying great engineering at scale. It was great to see team applying their products into interview pipeline also (using proton meet, proton docs for coding etc). Best of luck to Proton and I still believe in their mission!