Grab Database Engineer interview questions

The interview include hand one question on database like mysql. Also ask some other data base technology like Mongodb and elasticsearch. I will ask you what will be a good infra topology of a small cluster/ medium cluster and large cluster, and ask you to give detail on your design.

Skype interview with HR, asking about experience and background and then schedule a 30 min meeting with technical team. No feedback/no reply my emails from HR why I was not approved.