Like most software companies, you are spread pretty thin and under constant stress. From picking up calls in the weekend, debugging production, measuring impact of your own work, to of course delivering software to users, there is no way to specialize or do just what you like to do at Sonder.
Particular to Sonder, is how you are pushed out of your comfort zone. You might be a backend web developer, but if the need is for mobile development, well, you are a mobile developer now! This is unfortunate if you were planning to do a career in backend or frontend development.