Wise Front End Web Developer interview questions

1. If I start a startup would I prefer writing unstructured code in two month or clean, efficient, testable code in a year. (Comparing 2 vs 12 months is a totally unrealistic example. Experienced developer would add new features faster when she/he has clean and well designed code base. There will be fewer bugs also. A good code base would never take 6 times longer to develop.) 2. Would I spend time to add a feature to Web app or to migrate it to ES6? 3. Why do some of TransferWise users drop off at the fourth transfer flow process, which is entering billing information? 4. What would I change to make more users to enter their billing information? 5. How would I know that my change improved the statistics if there were 10 more changes?