I applied through a staffing agency.

It was time-taking. You can expect to spend the whole day at their office. My timing was from 10:30 am to 5:30 pm.

• 1st round: MCQ (easy) for 30 mins.
• 2nd round: Case study (develop a data-table without using plugins or frameworks using vanilla JS, HTML, and CSS) for 2 hrs 30 mins.
• 3rd round: Interview questions from HTML, CSS, and JS starting from basics till advanced features and architecture. It lasted around 2 hrs 30 mins for me.

The topics were basically everything: design patterns of JS, memory model, garbage collection, JS engines, load time improvement, caching in JS, web workers, service workers, client-side and server-side rendering, SSL, debouncing, ETags, and data types in JS. HTML included HTML5 features, meta tags, MIME types, canvas, and SVG. CSS covered CSS preprocessors, CSS3 features, animations, box model, and more.