DSA around graphs, linked lists, stacks, etc.
Design was based along batch processing, geo-fencing, lat-long validations, relaying, etc. Also, a ton of architectural discussions around identity and access management, API gateways, micro-services, service mesh, etc.
Design patterns I focused on were factory, abstract factory, builder, singleton, facade, proxy, adapter, decorator, etc.
Few fundamental discussions with Java and Spring (These were my strong points in the resume) specific questions along transactions, concurrency, data-structures, generics, dependency injection, etc.