A complete guide to integrating Google OAuth login with Next.js + NextAuth.js. Learn step-by-step Google Cloud Console setup, fix common errors like redirect_uri_mismatch and access_denied, and avoid deployment pitfalls on Vercel. Essential for developers building one-click Google login. Recently, I integrated Google OAuth login functionality into a project and encountered numerous pitfalls from configuration to deployment. I’ve organized…

Learn how to implement multiple middlewares in Next.js step by step. This guide covers authentication middleware, i18n (internationalization), modular middleware structure, and best practices for clean, scalable Next.js applications. When building medium-to-large Next.js applications, we often need to perform some preprocessing before requests enter the application, such as user authentication, internationalization settings, and redirects. Starting…