developer-quiz

Return your answers as a zip-file. Do not fork this repo.

Questions

Take approx. 15 minutes to answer each question. Use can use diagrams or whatever technique you find the best to explain your solution.

Question 1.

You are implementing a service that will receive videos uploaded from a mobile client and re-encode those videos. You have thousands of clients that are uploading video at the same time. Explain the software architecture for the service. What technology/architecture/patterns would you use and why?

Question 2.

How would you implement backend data storage for Facebook-messenger-like application (with similar scale), i.e. how would you store chat related data? Describe the data model and technologies you would use.

Question 3.

You are building an application running inside web browser. You have read a list of user's friends' usernames from server. List can contain hundreds of usernames. You need to implement a component that finds a usernames from this list based on user input. For example given a list of friend is ['fred', 'frank', 'jerry']. When user types fr, you should filter the list so that usernames containing fr are included. How would you implement this i.e. what data structures and algorithms would you use?

Programming task

Implement function diff to find changed values in two JSON objects. You can use any programming language but no external libraries allowed. Consider the performance of your implementation while keeping your code elegant. Provide code, tests & instructions how to run the tests. Given for example:

first = {
  "foo": {
    "bar": "baz",
    "biz": "foo"
  },
  "fiz": {
    "foo": "baz"
  },
  "bar": "baz",
  "baz": [
    "foo",
    "bar"
  ],
  "miss": 123
}

and

second = {
  "foo": {
    "bar": "baz1",
    "biz": "foo"
  },
  "fiz": {
    "foo": "baz"
  },
  "bar": "baz",
  "baz": [
    "foo1"
  ],
  "new_value": 1
}

Then diff(first, second) should return

{
  "foo": {
    "bar": "baz1"
  },
  "baz": [
    "foo1"
  ],
  "miss": "undefined",
  "new_value": 1
}