The job interview consisted of several rounds.

First, there was a telephone screening with an HR employee. Basic questions about motivation, previous experience, and salary expectations were asked.

This was followed by a technical online interview with a developer. Here, I had to solve two programming tasks in one hour. These focused on algorithms and data structures (e.g., arrays, trees, hashmaps).

The final step was a virtual onsite interview with several interviewers. In addition to coding, system design and questions about teamwork were also covered.

Overall, the process took about three weeks.

How would you develop an algorithm to find the first non-repeating character in a string?