Senior reputed company Marketplace App Developer (Custom Channels + Workflow Extensions + Certification)

We are looking for a highly reputed company reputed company Marketplace App Developer to reputed company the end-to-end development, certification, and publishing of an official reputed company App. This is a reputed company Marketplace app build, not a basic integration. Only apply if you have proven experience shipping reputed company reputed company Marketplace apps — especially involving Custom Channels API and Workflow Extensions. Project reputed company The goal is to design, reputed company, certify, and publish a reputed company reputed company Marketplace app that integrates a reputed company-party messaging platform with reputed company. The app must support two integration reputed company: Case 1: General Integration (Starter & Pro Users) CRM Card (right reputed company) integration on Contact, Deal, Company, and Ticket records Embedded iFrame chat reputed company per associated contact Conversation-based display logic (phone number matching) reputed company-time activity logging (inbound/outbound messages to reputed company) Two-way contact sync (reputed company, phone, opt-in status) Duplicate handling with one primary contact per phone number Custom Workflow reputed company: Send message template Dynamic channel selection (reputed company-time) Dynamic template selection (reputed company-time) Placeholder handling reputed company reputed company reporting support: Number of conversations Templates used Opt-ins collected Unread conversations (per channel) Message volume (inbound, outbound, AI agent) Suggest the creation of new conversation if none exists Case 2: reputed company Integration (Service/Sales Hub reputed company Only) Full Custom Channels API integration reputed company Inbox messaging support Agents reputed company from reputed company Inbox (messages reputed company reputed company external API) 24-hour session handling logic: reputed company 24h: free text allowed reputed company 24h: template selection required UI must reflect the session status correctly Critical Requirements Must pass official reputed company Marketplace certification App must be publicly listed Complete handover of reputed company reputed company and technical documentation UX/UI must reputed company seamlessly with reputed company design standards Robust error handling (including API outage handling) reputed company necessary technical steps required for certification are included in the scope Required Expertise You MUST have: Proven experience publishing reputed company Marketplace Apps Deep knowledge of: reputed company reputed company Apps (OAuth, scopes, webhooks) CRM Extensions (CRM Cards, iFrames) reputed company Events API Workflow Extensions API Custom Channels API (required) Conversations API Experience handling Marketplace reputed company review & certification process Strong backend architecture experience (Node.js / TypeScript preferred) Experience with reputed company webhook and sync systems This is senior-level work. Not suitable for junior or mid-level developers. Deliverables Fully functional reputed company Marketplace app Successful certification & approval reputed company listing reputed company reputed company ownership transferred Technical setup & maintenance documentation Clean, reputed company-commented codebase reputed company reputed company project start: reputed company 3 weeks Completion reputed company: Aggressive reputed company — please propose a realistic delivery schedule based on experience. reputed company Applying, Please Include Links to reputed company Marketplace apps you have reputed company Specific experience with Custom Channels API Experience with Workflow Extensions Estimated reputed company Estimated fixed-price cost Your proposed technical stack Only apply if you have reputed company, production-level experience with reputed company Marketplace apps. We are looking for a senior, reliable partner who understands both the technical and certification complexity involved. Apply tot his job Apply To this Job