Explain and profile are the two Cypher instructions that will help us get facts where we see possible performance issues.
Explain will give you the execution plan of your query without executing it, while profile will execute the query and return results.
The execution plan is not determined by a hitman but out of the text defining the query by a component of Cypher named the planner; there are two planners: cost planner and rule planner. Cost planner is used by default; it appeared in version 2.2. Its action is to smoothly turn a text into a list of operators (remember this name).