How I Cracked Google’s Onsite Interview: My Prep Checklist and Lessons Learned

This is a personal account of the author’s recent interview at Google, describing the process and the extensive preparation undertaken.

After signing a confidentiality agreement, the author outlines the interview flow: a brief chat with a recruiter, followed by two 45‑minute one‑on‑one software engineering sessions that involved whiteboard coding.

Preparation materials included reading Effective Java (2nd edition) , Programming Interviews Exposed , Coders at Work , and a combinatorial algorithms textbook, as well as studying Java Puzzlers to develop a critical mindset toward code.

The author also reviewed core topics such as concurrency (deadlock, livelock, mutexes, semaphores), tree traversals, depth‑first vs. breadth‑first search, A*, Dijkstra’s algorithm, balanced binary trees (red‑black, AVL, splay), graph representations, minimum spanning trees, and runtime analysis.

Practical exercises involved implementing six sorting algorithms with test‑driven development, coding hash tables using arrays and generics, and solving as many interview‑style problems as possible while avoiding speculative “guess‑the‑question” resources.

Additional steps included discussing interview expectations with friends already at Google, seeking advice from mentors, and conducting runtime analysis on sample code, such as calculating the sum of numbers from 1 to n and analyzing its O(n³) complexity.

The author emphasizes the importance of practicing whiteboard coding, planning the order of statements, and being aware of the differences between writing code on paper versus in an IDE.