Advanced Call Center and SMS Platform

Project Requirement: Call Center Dialer + SMS Platform

We are looking for an experienced development team/company to build a Call Center Dialer Platform with Web/Desktop + Mobile Applications, integrated with VoIP/SIP providers and SMS APIs.

1. Call Center Dialer
Predictive Dialer
Progressive Dialer
Power Dialer
Preview Dialer
Click-to-Call
Call queue management
IVR integration
Call recording
Call transfer, hold & mute
Call disposition / outcome management
Agent status management
Campaign management
Call history and detailed CDR
Real-time agent and campaign monitoring
Supervisor dashboard
Call analytics and reports
2. VoIP / SIP Integration

The platform should support integration with multiple VoIP providers through:

SIP
SIP Trunk
RTP
WebRTC
Provider APIs
Direct Switch connectivity

Features should include:

Multiple VoIP provider connections
Provider-wise routing
Least Cost Routing (LCR)
Failover routing
DID management
Caller ID management
Concurrent call limits
Real-time call status
CDR synchronization
Provider balance/usage monitoring
3. SMS Integration

Build a complete SMS module supporting:

One-to-one SMS
Bulk SMS
Promotional SMS
Transactional SMS
OTP
SMS campaigns
Scheduled SMS
Contact/group management
Sender ID management
Delivery reports
Failed-message reports
SMS templates
API-based SMS integration
Multiple SMS gateway/provider connections
4. Mobile Application

Android/iOS application for agents and users with:

Login & authentication
Agent dashboard
Make/receive calls
WebRTC/SIP calling
Contact management
Call history
SMS sending/receiving
Campaign access
Agent status
Notifications
Call disposition
Basic performance reports
5. Desktop Application

Windows/macOS desktop application with:

Agent login
Softphone
WebRTC/SIP integration
Call controls
Contact/campaign management
SMS module
Call history
Notifications
CRM integration
Background call handling
6. Admin & Supervisor Panel
Multi-tenant architecture
Admin/sub-admin/user roles
Agent management
Team management
Campaign management
Number/DID management
VoIP provider management
SMS provider management
Routing rules
Wallet/billing system
Usage monitoring
Call & SMS reports
Real-time dashboards
Audit logs
7. API & Integrations

The platform should be designed with APIs for:

VoIP/SIP providers
Direct Switch
SMS gateways
CRM systems
WhatsApp/other messaging platforms where applicable
Webhooks
Third-party applications
8. Suggested Technology

Backend: Node.js / NestJS
Frontend: React.js / Next.js
Mobile: Flutter or React Native
Desktop: Electron
Database: PostgreSQL + Redis
Real-time: WebSocket
Telephony: SIP / WebRTC / RTP
Queue: Redis/RabbitMQ
Infrastructure: Docker + Linux

9. Security & Scalability

The system should support:

JWT/OAuth authentication
RBAC permissions
API rate limiting
Encryption
Secure SIP/WebRTC configuration
Fraud prevention controls
Call/SMS usage limits
Detailed audit logs
Horizontal scaling
High availability
Monitoring and alerting
10. Expected Deliverables
Complete source code
Web admin panel
Agent web application
Desktop application
Android application
iOS application
Backend/API
Database architecture
VoIP/SIP integration
SMS integration
API documentation
Deployment documentation
Production deployment
Testing & bug fixing

Looking for: Experienced developers/team with proven experience in VoIP, SIP, WebRTC, call-center dialers, bulk SMS, telecom APIs and scalable communication platforms.

Please share your previous relevant projects, technical approach, estimated development timeline, team structure and commercial proposal.