Design & implement a Key-Value (KV) data store that can perform the following.

Key uniquely identifies an entry in the store. It would always be a string.

The value can be

• Primitive → String, Number (Integer, Long, Double, Float) & Boolean
• Collection
  • List of primitives (Ordered)
  • Set of primitives (Unordered unique)

Use Cases

• Primitives
  • Store a value against a key.
  • Fetch the value stored against given key
  • Delete a key
• Collection
  • Store a single value or multiple values against a key.
  • Fetch a single value or multiple values against a key
  • Delete a single value or multiple values against a key
  • Delete a key
• Type safety
  • The data type of the value/primitive is determined at the time of first insert.
  • The data type of the value/collection along with the holder primitive type is determined at the time of first insert.
  • For subsequent updates to the key, the type safety must be enforced.

Edit:
Time: 90 min
Company: Indian Fintech Startup
Not Selected.
My Sol: https://github.com/ak-17/DataStoreLLD (it's messy)
Expectation was something of the sort to use command pattern to run and get results of each command (Similiar to redis).
If someone has a better way to solve this, please share.