Need backend developer for my website with already existing frontend

I am looking for an experienced backend developer to help me take my existing Reactjs frontend website to the next level. I have specific functionalities in mind, and I am looking for someone who can work with me to make them happen. I need someone who is comfortable with a specific backend technology; preferably one that supports user authentication and database management . If you feel confident in being able to provide the solutions I need, then I'd love to hear from you!