Dear Sir,
I have read Project Description & for such long-term and big projects, you definitely need a team of developers, so in case one developer is not available then other can still continue working. Secondly, I would like to see your existing project and list of bugs along with new features. Yes, we do have experience in ReactJS, Node.JS, MongoDB etc. so technically there are no hurdles or issues.
Please click on the chat button for further discussion about your project, I can then also send you some of our recently developed websites URL.
Look forward to hearing from you & start further discussion thru' private chat.
Regards,
YK
LEADconcept