- DS and algo (array, linked list, stack, queue, graph, tree and all) - system design (LLD, solid principle, java, sql, no sql, scale, git, puzle, archi, ) a b c d -

Prepare for average DSA question, map internal working, solid principles. Singalton Design pattern is must. Explain every solid principle with example. Tree problems, Array problems. DP is very rarely asked, and some times BFS DFS related graph problems