Know how to implement basic data structures and when to use them. Know graph/tree traversal, breadth v depth etc. Explain Big O notation of your implementation

Know how to implement basic data structures and when to use them. Know graph/tree traversal, breadth v depth etc. Explain Big O notation of your implementation and efficiency trade offs. know how how/when to use alternatives when resource constrained, ie sorting a data set bigger than main memory. Be able to implement, and iterate, these on a whiteboard (practice!). If you can do all this you're most of the way there. Ps I found working through _programming interviews exposed_ as good practice.