These people are very unprofessional. They approached me for interviews and I took one round. It went very well, but then they ghosted.

On my first follow-up, they said the interviewer had not replied with feedback, and I never heard back from them.

If an interview doesn't go through or the profile/opening is closed, they should inform candidates of the same. People put in time to prepare and appear for interviews. At the very least, they could be professional and maintain transparency throughout the process.

Build a React app that has a normal table with delete row and filter features.

Follow-up question: How can we scale it for 1 million users?