Hi, Greetings from Appadurai of Yaali Biz Appln solutions.
I am a Salesforce certified developer with 15+ years of software industry experience and an ex-employee of Zoho. We have strong domain knowledge of various business having implemented 100s of projects in CRM system including Zoho and Salesforce.
We have done two way integration between Salesforce and other third party system using Rest services similar to your requirement.
https://www.freelancer.com/projects/php/Integrate-API-Salesforce/reviews
https://www.freelancer.com/projects/crm/Salesforce-Developer-API-Pay/
We have a skilled development team with both declarative and programming skills that includes building complex Validationrules, Workflowrules, ApprovalProcess, Process builder, relationship mapping, developing Visual Force pages, Apex Classes , lightning components, third party Integrations using SOAP and Rest Services .
Looking forward to discuss the details.