Applied through their website and responded, requesting a phone interview one month later.

They flew me to New York two weeks after the phone interview. Very generous with travel expenses, everything was handled fast and professionally. They paid for a nearby hotel and for transportation from the airport.

Great experience, amazing offices, friendly, outstanding people!

You have a binary tree where each node has three pointers: left, right, and side. Set the side pointers of the last level of the tree to point to their nearby nodes.

Find if an expression containing '(', '[', and '{' is syntactically correct.

Given some rules of an alphabet (e.g., a->c, meaning 'a' comes before 'c'), find the alphabet.

How to find the total area of some overlapping circles.

How to design an optimal cache, considering what and how to use known data structures.