Due to Lack of Time I couldn't do some stuff which I've mentioned below. 1: I would have styled it better with responsive design and diferent even odd rows styles. 2: I would've used uniform data store across both pages. I didn't because I wanted to demonstrate use of memoization in Sum page. 3: I would've used one single table across both pages. due to shortage of time I couldn't make it resuable across pages. 4: I would've wrote more tests. 5: I would've implemmented a more stricter linting configuration. 6: would've used proper types instead of any at some places. 7: I would've used react-virtualized table to make it more performant.