Table of contents

  1. 1. Morgan Stanley - Full Stack Java Interview
    1. Questions on Java
    2. Question on Business knowledge

1. Morgan Stanley - Full Stack Java Interview

Questions on Java

  1. Name the difference between a class & an interface Ans:
    • class: a blueprint for creating objects.
    • methods can hold actions
    • member variables can hold properties
      • interfaces: a contract that binds the class to obey
    • Interface defines actions (methods) that a class must follow (similar to @abstractmethod in python!)
    • contains only method signatures with NO IMPLEMENTATION (you can add implementation tho since Java 8)
    • Example Code:
      interface Animal {
       void makeSound(); // Kinda an Abstract method
  }

  class Dog implements Animal {
       @Override
       public void makeSound() {
            System.out.println("Woof!");
       }
  }
  2. Java Multi-threading, what is it and how to use it? Ans:
    • Multi-threading = doing multiple-tasks at the same time
    • In Java, you can use interface Runnable or class Thread to let tasks run in parallel
  3. What different testing skills are used in Java ? Regression, Unit, Smoke… Ans:
    • Regression testing: Ensuring new changes (i.e. bug fix/ new features) don’t break production, focusing on BAU performance
    • Unit testing: Testing single function/ parts of code
    • Smoke testing: Quick test to see basic features still working (pre-lim testing)
    • integration testing: Ensuring different modules and components work well together, focusing on interactions (e.g. frontend and backend)
  4. Benefits of OOP (in Java or in coding in general) Ans:
    • There are mainly 3
    • reusability: reusing instead of copying code
    • organized: Easier to understand and manage
    • flexibility: changing scope of a code
  5. How does a Java service component connect to its client/ server side ? Ans:
    • Client <-> HTTP Requests <-> Server
    • Using REST APIs
  6. How are maps used in Java? Ans:
    • map = dictionary, storing key-value pairs
  7. How are maps different from each other (Difference of Ordered Map vs Hash Map) Ans:
    • HashMap: Order of items NOT IN order
    • Ordered Map: Keeping order of items in specific order
  8. What are the design patterns used in Java projects? E.g. Singleton… Ans:
    • Design patterns: templates for solving coding problems
    • Examples:
      • Singletons: 1 class instance only

Question on Business knowledge

  1. What is an ELN (Equity Linked Note) Ans:
    • Mix of loan & investment
    • Money grows on company stock performance
  2. What is an option? Ans:
    • Guaranteeing you buy/sell a stock at fixed price in the future
    • Like a supermarket coupon, you can choice to exercise/ not exercise
    • Strike price : to buy/sell at fixed price
  3. What is a swap? Ans:
    • Trade between 2 counter-parties
    • 1 takes variable interest vs 1 takes fixed interest
  4. How does an iBank make money (as a sell side) Ans:
    • Sell side helps companies and charges fees in services
  5. Difference between Equity and Equity Derivative Ans:
    • Equity: Owning parts of company (owning company stocks)
    • Equity Derivatives: Financial product with underlying as equity.
    • Not directly owning company stocks
    • Trading on contract based on stock’s performance
    • Example: an option, future, swaps
    • Allows user to leverage investments
      • Controlling large amounts of stocks for small investments (Price of option < price of stock)
    • Allows users to enter speculative bets
      • Not owning the stock
      • But high risk high return