Requirements

Functional Requirements:

• Create a short URL for a given long URL.
• Return the long URL associated with a given short URL.

Non-Functional Requirements:

List the key non-functional requirements (eg low latency, scalability, reliability, etc.)...

API Design

The api can be simple, stateless, horizontally scalable.

It needs endpoints such as:

• POST url/<long-url>
  • This endpoint will generate a short code, save it in the ID (as primary or indexed key) along with the long url
• GET url?shortUrl=shortUrl
  • This endpoint is what the main page will use via JS at load time to redirect the user from the short url to the long url

High-Level Design

The high level design is at the diagram.

• Landing page for ourTinyUrl.com. All requests land here, the client will query GET url?shortUrl, get a longUrl and redirect the user to the destination url
• We have a scalable simple API with the 2 endpoints described above. We can have a load balancer in front of the API and as many instances of the API we want.
• A DB that could be a cluster with master(writes) and slave (reads) architecture in case we need to escalate the DB layer too

Detailed Component Design

• API
  • The 2 endpoints mentioned above
  • Scaling by having a load balancer in front of the API and as many API instances as needed
• DB
  • 1 table to store short and long url mappings is all that is needed
  • Retrieval is O(1) already since we'll always query by an indexed column (short url code)
  • Could be scaled further by having a master (writes) / slave (reads) design