Solid Apps

PHP backend case study

URL Shortener

Context: a small REST API for shortening links. The problem is that even a simple endpoint needs URL validation, custom aliases, repeatable shortening, and click statistics.

Discuss a similar problem Back to projects

Case study

Technical scope

Some repositories are private until the work is closed. Project scope, technical decisions, and operating scenarios are described on the page. I can discuss the code during a technical conversation.

01

Problem

  • A short-link service needs stable short codes, input validation, and duplicate prevention for the same original URL.
  • The main risks are invalid URLs, alias conflicts, divergent web and CLI behavior, and no visibility into click activity.
02

Technical decision

  • Service layer, reverse lookup for repeated shortening, alias validation, separate ClickTracker, and a persistence boundary that can be replaced later.
  • UrlShortenerService coordinates validation, reverse lookup, persistence, and code generation so entrypoints stay thin.
  • Repository interfaces hide file persistence, while ClickTracker separates redirect behavior from statistics recording.
03

Result

  • The project shows discipline in a small API: predictable redirects, no duplicates for the same URL, click stats, and a simple path to changing storage.
  • Base62 code generation, URL validation, and custom alias handling.
  • Shared web/CLI logic for shortening, lookup, and statistics.
  • Click tracking and a simple statistics endpoint for shortened links.
04

Stack

  • PHP / REST API / Base62 / Stats
  • composer install
  • composer serve
  • composer demo-idempotency