Amazon Software Engineer In Test interview questions

Contacted by a talent sourcer who found my profile in LinkedIn. I had 4 phone interviews including 2 technical phone screeners. Then I was invited to London for 5 face to face interviews. phone coding questions : 1 - Write a function that takes an integer N and returns the Nth number of a Fibonacci suite. 2 - Given a list of Integer. Write a function that takes an integer and returns all the pair of integers included in the given list that sum up with this integer. Face to face coding questions : 1 - Write a function that takes an integer and return a string of this integer in Roman number format. 2 - Go game. Write a function that takes a position (x,y) in a go game graph and returns a boolean telling if this position contains a white or black piece and if this piece is trapped or not. On each question I was asked to write the tests for my code. The recruiter gave me a complete feedback for all the interviews and the whole process, so this experience was very positive and I could know that I was very close to get an offer as some interviewers were very positive (they found I had "excellent testing skills"). There was a huge gap between the phone questions and the face to face questions (Especially the go game question) : for the go game question, the time was really short (< 30mn), I could draw the main algorithm and show that with few minutes more, I could get to a smart working code (recurrent call on each neighbors), but the interviewer expected me to go directly to the solution, he was very nervous and not helpful…. I am still wondering why they did quite easy questions on the phoning interviews, invited me to london to ask very difficult questions (almost impossible without knowing the solution by heart), it would probably be more economic to switch (difficult questions on the phone….). It seems that it's depending on the interviewers, so luck as an important role (as interviewers can be more or less cool). However, it was a very interesting experience and I'm very grateful to amazon and my recruiter.