Which Language Should You Use in the Amazon Coding Interview?

Amazon lets you use any mainstream programming language in both the online assessment and the onsite coding rounds. The interviewer grades whether your code is correct, readable, and idiomatic, and whether you can explain it, not which language it is written in. Java, Python, and C++ are the three most common choices, and none of them earns extra credit over the others.

Idiomatic code means code written the way experienced users of that language write it, so a Python solution uses a dictionary rather than a hand-built hash table. That is the standard you are measured against. The language itself is your decision.

The online assessment accepts the usual language list

The Amazon online assessment, often shortened to OA, runs on HackerRank. HackerRank supports the common industry languages, including Java, Python, C++, C#, JavaScript, Go, and Kotlin, so you will not be forced into an unfamiliar one. You pick the language from a menu inside the editor before you start each problem.

The onsite rounds are less formal. You write in a shared online editor, and the interviewer reads the code as you type it. The full assessment format is described in What Is the Amazon Online Assessment Like?.

Trade-offs between the common languages

Python is the fastest to write, which matters when a 45-minute round contains two problems. A depth-first search over a deep tree can exceed the default recursion limit, so either raise the limit or rewrite the search with an explicit stack. Java takes longer to type but reads clearly, and it is a good choice when the role you applied for is on a Java service team. C++ runs fastest, but manual memory handling and iterator invalidation cause errors that are easy to miss when time is short.

What the interviewer looks for

The interviewer reads four things in your code. Names should say what a variable holds, so seenChars rather than s. Edge cases should be handled visibly: an empty input, a single element, duplicate values, and the largest allowed size. Time and space complexity should be stated out loud before you finish, for example "this is O(n) time and O(k) space for the window". Finally, you should test the code by tracing one small example through it line by line.

Amazon interviewers do ask questions of the kind found on LeetCode, most often from the medium band. Does Amazon Ask LeetCode Questions in Interviews? lists the patterns that appear most often.