Hello everyone!
Got this today at onsite at EU fintech company:
public interface RateService {
public ToDo calculate(Todo todo) {
return ToDo;
}
}
public class ClientService {
RateService rateService; // already inject
public Todo calculate(ToDo todo) {
return ToDo;
}
}I need to design and develop service, which calculate the total sum before exchange operation. Example: user sell 100 EUR, receive 119 USD, etc ( GBP ->EUR / RUB -> USD )
Rates comes from external "service" interface, which each call costs to company 0.001$ and Client Service should have lattency 200ms. And I need to design classes and write code.
My idea was: Create class / HashSet for storing rate info / queue for delete old rate from out hashSet
Created a class: for save info from rateService.
class Currency {
private String debitCurrency;
private String creditCurrency;
private BigDecimial rate;
private Long timeStamp;
// getters , setters, equals, hashCode, construtors
}Function and internal logic
public BigDecemial calculate(BigDecemial amount, String debitCCY, String creditCCY) {
// Create object of currency class, using debitCCY, creditCCY and timeStamp
// check if this object is too old for getting currency from it and we need to delete from queue and hashSet
// if object exist in hashset, calculate amount based on rate
// else get info from service, put in hashSet, queue
// return to customer
}How you will be design this in 40 minutes ?
There is no need to RUN code.
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