React & Next.js Feature Enhancement

I'm looking to add features to an existing website using React and Next.js. The primary features to be added are:

User Authentication
E-commerce Functionality

Additionally, I need to integrate several third-party tools:
Payment Gateways
Social Media Logins
Analytics Tools

Ideal skills and experience:
- Expertise in React and Next.js
- Experience in implementing user authentication and e-commerce functionalities
- Familiarity with integrating payment gateways, social media logins, and analytics tools
- Strong problem-solving skills and attention to detail
- Ability to work collaboratively and communicate effectively

Please provide relevant work samples and a brief overview of your approach to this project.