Code up a calculator backend for a ui. Algorithms: maximize stock price on trading (leet coding problem). Backup question, distribute problem across multiple hosts, insight ordering is important for prices and the local maximum may be the best trade. Reverse a linked list (wasn't prepped - leet code question). Math: calculating area, displacement of water questions, earth warmer in summer over winter, why. Lots of stuff that may or may not apply to work but test for a certain personality type. Last coding exercise was more interesting, implement Promise.all type of code, involves semaphores, you can cheat because js is single threaded on firing callback when final task is finished.