You should know, in decreasing order of importance: BFS DFS Topological Sort & Shortest-path in a DAG Dijkstra's algorithm Bellman-Ford A-star (A*) Floyd-Warshall (debatable, but it's 5 lines of code, so no reason not to know it) With the exception of Floyd-Warshall, I have seen every single one of these topics come up in a Google interview. BFS & DFS are self-explanatory. There are a huge number of variants that can be asked using them.

Recruitment is insane - you don't know the project, very tedious (second step is circa 5 hours), you don't know the team - they will try to match you to one when you pass coding session. You need to write, error free, working code on notepad. I don't recommend however the staff was friendly.