I had an initial coding HackerRank assessment which included 3 questions. This was followed by a phone interview with a development manager, featuring a CoderPad test. Subsequently, I attended an onsite interview in Chicago, with my flight and hotel accommodations covered by Citadel.

Overall, the interview process was enjoyable. The recruiter and Citadel maintained professionalism throughout, keeping me informed of my status.

HackerRank Test:

1. Print the Roman numeral equivalent for numbers 1-1000.
2. Order a list of words appearing in a file by the number of letters, but maintain the original order ("stable sorting") of words with the same length.
3. Implement a stack class with methods to perform specific operations mentioned in the question.

Phone/Codepad Interview:

1. Given a series of prices, find the buy/sell trade pair that yields the maximum profit.
2. Modification of question 1: For the same prices, find the maximum profit possible with any number of buys and sells allowed. (At each step/price, you can buy, sell, or do nothing; short selling is not allowed.)