02 / Links and application APIsFull-Stack Software Engineer (Sole Developer)

NanoLink

Production-style URL management application with custom links, passwords, expiry and click tracking.

01 / The Problem & Analysis

Standard URL shorteners lack security controls, expose private redirects to scraping, and lack programmatic lifecycle and one-time deactivation rules.

02 / Engineering & BA Role

Full-Stack Software Engineer (Sole Developer)

03 / Outcome

Redirects check the stored expiry date and deactivate single-use links after their first visit.

Overview

NanoLink is a URL shortening application that lets users create short links with optional custom aliases, password protection, expiration and one-time use. The application also records click counts and link activity.

What I built

Engineered REST API routes in Next.js App Router with Zod schema validation, Prisma ORM transactions, and conditional redirect resolution.

Product Interface

NanoLink real application interface from the deployed site

Engineering Decisions

Validate link requests

What: The create-link API checks the submitted URL and options.
Why: Invalid input should return a useful error before a link is saved.
How: The route validates the request, normalizes the URL and checks it before creating the record.

Keep identifiers unique

What: Short codes and custom aliases have database uniqueness constraints.
Why: A short link must identify one destination.
How: The API checks existing codes and PostgreSQL also enforces unique values.

Apply link rules

What: Links can require a password, expire or allow one use.
Why: The person sharing a link needs control over how it is opened.
How: The redirect workflow checks the stored options. One-time links become inactive after use.

Record link activity

What: A link stores its click count and last visit.
Why: The owner can see whether the link is being used.
How: The application updates the link record when handling a visit.

Data Architecture & Schema

The PostgreSQL Link model stores the original URL, short code, optional alias, password hash, expiry, activity status and click information. Short codes and custom aliases are unique. This keeps link options together with the destination they control.

originalUrl: Destination URL
shortCode: Unique short identifier
customAlias: Optional, unique alias
password: Optional password hash
expiresAt: Optional expiry date
oneTimeUse: Single-use setting
clicks: Visit count
lastVisited: Last visit time
isActive: Whether the link is active

API & System Workflow

POST /api/links receives the URL and options, validates the request, checks the alias, hashes a supplied password and creates the link record. A successful creation returns the new link with HTTP 201. Invalid input returns an error response.

Request
Zod Validation
Application Logic
PostgreSQL
Response

End-to-end system lifecycle

Representative Implementation

API validation & persistence · Creating the Link record. Excerpt from the repository source.

const newLink = await prisma.link.create({
  data: {
    userId,
    originalUrl: normalizedUrl,
    shortCode,
    customAlias: parsed.customAlias || null,
    password: hashedPassword,
    expiresAt: parsed.expiresAt ? new Date(parsed.expiresAt) : null,
    oneTimeUse: parsed.oneTimeUse,
  },
})01const newLink = await prisma.link.create({
02  data: {
03    userId,
04    originalUrl: normalizedUrl,
05    shortCode,
06    customAlias: parsed.customAlias || null,
07    password: hashedPassword,
08    expiresAt: parsed.expiresAt ? new Date(parsed.expiresAt) : null,
09    oneTimeUse: parsed.oneTimeUse,
10  },
11})

API validation & persistence · Creating the Link record

Read file on GitHub

Interface & Features

The form connects the destination URL and optional link settings to the create-link API. The result gives the user a short link to share.

Request validation
Custom aliases and unique links
Password and expiry checks
Click tracking and one-time use

Technology Stack

Next.js
TypeScript
Node.js
PostgreSQL

TypeScript · Next.js · Node.js · PostgreSQL · REST APIs · Authentication/security-related application logic · Database constraints · Error handling

Source Repositories

Open GitHub repository

Create-link API route Link data model Link redirect workflow

Live Deployment

Run NanoLink