Implement Google Oauth for Saas Application User Authentication

We are seeking an experienced developer to integrate Google OAuth into our existing SaaS application. The primary goal is to enable users to sign up and log in using their Google accounts, providing a seamless and secure authentication experience. The project involves configuring Google API credentials, implementing the OAuth flow on both the frontend and backend of our application, and securely managing user data obtained through Google. The freelancer will be responsible for ensuring proper token handling, session management, and adherence to best security practices. A clear understanding of OAuth 2.0 protocols and experience with similar integrations is essential. The final implementation should be robust, scalable, and fully functional.