Neet to build whatsapp platform

Looking for a developer to build a whatsapp platform has from which clients can do the following :

1- register a memebership in website
2- send bulk whatsapp messages to contacts
3- Groups and whatsapp contacts
4- import contacts into groups
3- messages history
4- api for developers from which developer can integrate with our whatsapp platform and send whatsapp messages from their system
5- subscription plan : client can subscribe for a plan from our whatsapp platform

Note : looking for a developer has experience in same whatsapp api and already knows hot do such whatsapp api