Amazon | SDE 1 | Round 1 | On Campus | India | Feb 2022

As a 4th-year ECE student from a Tier 2 college, I had my first technical interview for an SDE1 position at Amazon through an on-campus opportunity. This took place in India in February 2022. The round began with a brief self-introduction and a discussion about my projects. The core of the interview was a coding problem: Given two words, beginWord and endWord, and a dictionary wordList, return the number of words in the shortest transformation sequence from beginWord to endWord, or 0 if no such sequence exists.

I implemented a BFS-based solution. I utilized a hashset for wordList entries and another for tracking visited words. Starting from beginWord, I systematically explored 'sibling' words (those differing by one character) using a queue, ensuring they were in the wordList and unvisited. I continued this process until endWord was reached or all possibilities were exhausted. I took about 20 minutes to devise the approach and another 20 minutes to code and explain it. The interviewer then asked me about the time and space complexity of my solution, which I was able to answer correctly. The overall experience was positive; the interviewer was kind and supportive. I've since received an invitation for Round 2.