Airwallex Staff Data Scientist Interview Experience — Five Rounds, Rejected After the HM Round

The whole loop was five rounds, and every round felt like leveling up to fight a bigger boss.

Round 1: SQL + case

The SQL was basically similar to a post I'd seen before — there were some variations in the questions, but the type of question was the same.

After the SQL there was a case. The case gives you a credit card approval rate time series from Jan 2013 to Jan 2015. There's a dip in Feb 2013, a small surge in Nov 2013, and then it starts growing from Jan 2014. They ask what your read is and what your assumptions are. I said the Feb dip could be an internal issue — a feature launch, something technical... The Nov 2013 surge looked like it came from running an A/B test that caused the surge, and it looked successful, so they launched it in Jan 2014...

Round 1 went smoothly and I moved on to round 2.

Round 2: a deep-dive case round with a Staff DS

The first question was also a time series. The question was similar to round 1's, but this time you had to dig deeper into why the dip happened — you had to think about the relationship between the numerator and the denominator (it was also a conversion rate).

Second question: we're on the Airwallex page now, and they want to swap the "See a Demo" and "Get Started" buttons. What problem do you think this is trying to solve, why would they do this, and if they did it, how would you measure success.

Round 3: with the hiring manager

The HM round was all classic behavioral and past-experience questions. Maybe it wasn't a great match, and I didn't pass.