Round 1 :
2. String Manipulation Question
Round 2 :
1. Design classes where you need to expose one api to client, to search food items from list of restaurants(Let’s say 3 restaurants). Each restaurant will expose you getMenu() API, having different request and response structure. You need to return the client list of a searched item from all 3 restaurants.
2. Given a engineer, can have common attributes like communicate(), and can have specialized skills as well like doCoding(), fixCar(), makeRobot(). Make class diagram of engineer who can let’s say do both coding and make a robot.
Round 3 :
HLD of chat bot System. Query can be of two types – either hotel booking or flight booking.
Ex – My refund status, cancellation charges of the order. Depending on type of question, different api’s of internal team can be called to get data. We allow user to ask custom questions as well, that will help if that particular question is not available in our system then analytics team can look into that question and act accordingly. Also we need to keep last 1 question and its answer in recent chat for 24 hrs.
Cross Question – How you will maintain the mapping of question asked and the relevant api that needs to be called.
Round 4 (Director of Engineering) :
Build a system like IRCTC
1 Search trains by stations and date to get List of trains
2.Show route / schedule and availability of seats for a particular train and date
3. Book tickets
Areas to discuss
i) Database Model / Schema:
1. What will be your algorithm to compute seat availability from source station to destination station for given date for a particular train?
Input : I want to book 1 seat from Delhi to Varanasi on 20th Oct in 2nd AC
Rajdhani Express - 12768
Delhi -> Kanpur -> Allahabad -> Varanasi -> Patna -> Kolkata
Running Daily
Allowing booking for next 90 days
ii) APIs / Services:
1. searchTrains(fromStationId, toStationId, journeyDate) : List<Train>
-> How you will optimize your search? what will be structure of your cache?
2. BookTicket()
-> How you will handle race condition, 1 seat available, and 100 users try to book that seat at the same time.