"Senior software engineers are the most experienced member of a software team and usually carry the most responsibility and authority of that team. Because of this, interviews will be designed to find candidates who have expert knowledge of the field and years of experience as a software engineer. Expect to be asked tough technical questions and to give examples of previous projects that you have worked on."
Design a method of determining whether or not a linked list contains a cycle.
Read up on Floyd's Cycle-Finding Algorithm (The Tortoise and the Hare Algorithm). You use two pointers to traverse the list at different rates and if they become equal at some point without reaching the end of the list, then there is a cycle.