All the questions I got were "trick" JavaScript questions such as how to use native "apply" function, "this" keyword in tricky scenarios, and mutate prototype function. These types of questions/scenarios are rarely encountered, and can be easily looked up when the need arises. The type of questions I would expect for this position would be related to the skills listed in the job posting and allow the candidate to demonstrate knowledge and understanding of items such as front end design patterns, React hooks, CSS/SCSS, security and performance consideration, client API, state management, testing patterns, best practices, etc as well a host of other "soft" skills such as team or developing mentoring, establishing process, communication and interpersonal skill, etc. If they're proud of themselves for these kind of trick questions, it would be difficult for them to find an actual good senior engineer.