System design generic app, leetcode bfs problem.

Round 1: 1. Find first non repeating character in a string. Eg: “ababcdab” -> c 2. Flatten object: Convert this: { name: "Alex", address: { city: "Karnal", pincode: "132001", }, hobbies: ["reading", "writing"], education: { courses: ["abc", "xyz"], } } To: { name: “Alex”, address.city: "Karnal", address.pincode: 132001, hobbies[0]: "reading", hobbies[1]: "writing", education.courses[0]: "abc", education.courses[1]: "xyz", }