How would you design a URL shortener like TinyURL? (Pastebin / Bit.ly)

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Accepted Answer

## Step 1: Use Cases, Constraints, Assumptions, Back-of-Envelope

### Use cases
We'll scope to handle only the core flows that expose the bottlenecks; everything else is deferred.

- **User** creates a paste / short URL — POST long URL or text, get back `https://sho.rt/Ab3x9K` (302 redirect for URL, render for paste).
- **User** reads a paste/short URL — GET `/Ab3x9K`, cache-hit serves in <10ms, miss hits DB then populates cache.
- **Service** generates short code — deterministic Base62 of auto-increment ID (O(k) time, k=7) or content hash with collision check.
- **Service** tracks analytics asynchronously (clicks, referrer) without blocking read path.

### Out of scope
- User accounts/profiles, complex ACLs, real-time collaborative editing, full-text search inside pastes (defer to Elasticsearch), URL preview rendering.

### State assumptions
- 100M monthly active writers, 100:1 read:write ratio (1B reads/mo).
- Average paste/URL record 10 KB (including metadata), short code 7 chars (6

How would you design a URL shortener like TinyURL? (Pastebin / Bit.ly)

Understand the problem

Attempt it yourself

Study the solution

Step 1: Use Cases, Constraints, Assumptions, Back-of-Envelope

Use cases

Solution ready — 2 min read

Join the discussion

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KEEP THE
STREAK ALIVE.

Understand the problem

Attempt it yourself

Study the solution

Step 1: Use Cases, Constraints, Assumptions, Back-of-Envelope

Use cases

Solution ready — 2 min read

Join the discussion

Discussion (0)

KEEP THESTREAK ALIVE.

KEEP THE
STREAK ALIVE.