You will get Outbound and Inbound Calling | IVR | CCaaS/IPPBX or AI Voice/Call Agent
Top Rated
Project details
Looking to automate phone calls with a lifelike voice assistant? I will build and white-label a custom AI voice agent powered by GPT-4, Whisper (STT), and Amazon Polly or ElevenLabs (TTS).
✔️ Fully branded dashboard
✔️ Twilio call handling
✔️ Whisper or Deepgram transcription
✔️ GPT-4 response generation
✔️ Polly/Coqui/ElevenLabs voice synthesis
✔️ GoHighLevel (GHL) CRM sync
✔️ n8n automation (open-source Zapier)
Perfect for real estate, med spas, law firms, e-commerce, or agencies.
Generate leads, book appointments, or answer FAQs — automatically — with a human-sounding AI phone agent, branded as your own.
Let’s take your business voice-first. 🚀
✔️ Fully branded dashboard
✔️ Twilio call handling
✔️ Whisper or Deepgram transcription
✔️ GPT-4 response generation
✔️ Polly/Coqui/ElevenLabs voice synthesis
✔️ GoHighLevel (GHL) CRM sync
✔️ n8n automation (open-source Zapier)
Perfect for real estate, med spas, law firms, e-commerce, or agencies.
Generate leads, book appointments, or answer FAQs — automatically — with a human-sounding AI phone agent, branded as your own.
Let’s take your business voice-first. 🚀
Purpose
BusinessIndustry
Business Services & Consulting, Construction, Data Analytics, Ecommerce, Education, Events Planning, Fashion & Apparel, Financial Services, Food & Beverage, Government & Public Sector, Hardware & Electronics, Lifestyle, Logistics & Supply Chain Management, Manufacturing & Storage, Marketing & Advertising, Media & Entertainment, Medical & Pharmaceutical, Nonprofit, Real Estate, Religion & Spirituality, Retail & Wholesale, Software, Sports & Fitness, Telecommunications, Transportation & Automotive, Travel & Tourism, WellnessLanguage
EnglishWhat's included $799
These options are included with the project scope.
$799
- Delivery Time 10 days
Optional add-ons
You can add these on the next page.
Fast 7 Days Delivery
+$1,000
67 reviews
(57)
(8)
(2)
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This project doesn't have any reviews.
MW
Moshe W.
Aug 10, 2026
30 minute consultation
Just started and is going well. Going through out FreeSwitch system and cleaning bugs and identifying other issues
GL
Gady L.
Jul 20, 2026
IVR & Alert System Development Agreement
Working with Pankaj has been an outstanding experience from start to finish.
He consistently demonstrated exceptional professionalism, strong technical skills, and a true sense of ownership over every task.
What impressed me most was not only the quality of his implementation, but also his commitment to understanding the business requirements, collaborating with the team, and continuing to improve the solution until everything worked exactly as expected.
Throughout the project, he was always responsive, patient, and proactive.
Every commitment he made was delivered, and every challenge was approached with a positive attitude and a well-thought-out solution.
Beyond the development work itself, Pankaj invested time in creating comprehensive technical documentation and knowledge transfer materials to ensure the project will remain maintainable and scalable in the future. That level of long-term thinking is rare and greatly appreciated.
I highly recommend Pankaj to anyone looking for a reliable, talented, and dedicated software engineer. We are extremely satisfied with his work and definitely look forward to working with him again on future projects.
He consistently demonstrated exceptional professionalism, strong technical skills, and a true sense of ownership over every task.
What impressed me most was not only the quality of his implementation, but also his commitment to understanding the business requirements, collaborating with the team, and continuing to improve the solution until everything worked exactly as expected.
Throughout the project, he was always responsive, patient, and proactive.
Every commitment he made was delivered, and every challenge was approached with a positive attitude and a well-thought-out solution.
Beyond the development work itself, Pankaj invested time in creating comprehensive technical documentation and knowledge transfer materials to ensure the project will remain maintainable and scalable in the future. That level of long-term thinking is rare and greatly appreciated.
I highly recommend Pankaj to anyone looking for a reliable, talented, and dedicated software engineer. We are extremely satisfied with his work and definitely look forward to working with him again on future projects.
GF
Giorgio F.
May 24, 2026
Linux/VoIP Sysadmin Hetzner CX42 + PJSIP 2.14.1 + Twilio SIP Trunk Experts only Fixed$180
Pankaj delivered solid, production-grade work on the voice AI pipeline integration (VoIP, RTP, Whisper STT, Anthropic LLM, Inworld TTS). The stabilization phase brought real improvements: clean async architecture, working barge-in handling, multilingual fallback logic, and tested deployment on Hetzner. Documentation was thorough and the codebase was left in a maintainable state.
Communication was professional and reliable throughout the engagement. He raised technical concerns proactively and explained trade-offs clearly.
I recommend Pankaj for VoIP, real-time audio, and AI voice pipeline projects.
Giorgio
Communication was professional and reliable throughout the engagement. He raised technical concerns proactively and explained trade-offs clearly.
I recommend Pankaj for VoIP, real-time audio, and AI voice pipeline projects.
Giorgio
GF
Giorgio F.
Apr 26, 2026
Linux/VoIP Sysadmin Hetzner CX42 + PJSIP 2.14.1 + Twilio SIP Trunk Experts only Fixed$180
"Pankaj delivered Block 1 professionally and on time. He solved technical problems independently, switched from PJSIP to Asterisk autonomously when needed, and communicated clearly throughout. Clean documentation and reliable work. Highly recommended."
SF
Steven F.
Apr 23, 2026
CDL Development Backend
Pankaj was highly responsive and quickly grasped the requirements for a complex digital forensics task. He delivered a thorough forensic report in multiple formats, proactively supplemented his work with additional analysis, and offered helpful guidance on tooling. Communication was prompt and professional throughout. Recommended for backend/forensics and data-parsing engagements
About Pankaj
FullStack Dev FreeSWITCH | Asterisk | AIVoice Agent | SaaS | Js/PHP/Py
100%
Job Success
Delhi, India - 2:04 pm local time
I help startups, Individual/Small Firms, CCaaS, enterprises, and SaaS Firms design, build, deploy, and scale production-ready software platforms.
With 20+ years of engineering experience and 90+ successful Upwork projects, I take complete ownership of the engineering lifecycle from solution architecture and UI/UX implementation to backend services, APIs, AI integration, telecom infrastructure, DevOps, cloud deployment, documentation, and long-term production support.
Unlike specialists who only focus on one layer of the stack, I build complete business platforms that are scalable, maintainable, secure, and production ready.
Whether you need a communication platform, AI Voice Agent, SaaS application, customer portal, enterprise dashboard, workflow automation, or cloud-native backend, I can architect and deliver the complete solution.
What I Build
Enterprise SaaS Platforms
I design and develop complete SaaS products including:
Multi-tenant SaaS applications
Customer portals
Admin dashboards
CRM & ERP platforms
Contact Center (CCaaS)
Hosted PBX & UCaaS
Workflow automation platforms
AI-powered business applications
Internal enterprise systems
From MVP to enterprise-scale production deployments.
Full-Stack Software Development
I provide complete product engineering across frontend, backend, APIs, databases, cloud infrastructure, and production deployment.
Frontend:
React
Next.js
Vue.js
TypeScript
Tailwind CSS
Material UI
Responsive Web Applications
Progressive Web Apps (PWA)
Mobile-first UI
Backend:
Node.js
NestJS
Python
FastAPI
Django
Laravel
Go
PHP
Database
PostgreSQL
MongoDB
MySQL
Redis
API Development
REST APIs
GraphQL
WebSockets
OpenAPI / Swagger
OAuth
JWT
MCP Servers
Webhooks
Third-party integrations
AI Engineering & Intelligent Automation
I help businesses integrate AI into production systems—not just prototypes.
I build:
AI Voice Agents
AI Receptionists
AI Customer Support
AI IVR Systems
RAG Applications
Agentic AI Systems
Knowledge Assistants
Internal AI Platforms
AI Workflow Automation
AI Document Processing
AI Search Platforms
AI Technologies
OpenAI
Claude
Gemini
Deepgram
ElevenLabs
LiveKit
LangChain
LangGraph
MCP
Prompt Engineering
Model Optimization
Vector Databases
Realtime Voice APIs
Telecom & Communication Platforms
Telecom remains one of my strongest engineering specialties.
I build complete communication platforms not just PBX installations.
Technologies
FreeSWITCH
Asterisk
FusionPBX
FreePBX
VICIdial
SIP
RTP
WebRTC
SIP.js
ESL
AGI
AMI
ARI
Services
Multi-tenant PBX
Hosted PBX
Contact Center (CCaaS)
UCaaS
AI Voice Platforms
Softphones
Predictive Dialers
Progressive Dialers
Call Recording
Call Analytics
IVR Development
Queue Management
DID Provisioning
Carrier Integration
SBC Integration
Telecom Billing
White-label Telecom Platforms
Cloud Infrastructure & DevOps
I deploy highly available production environments.
Infrastructure
Linux
Docker
Kubernetes
Terraform
Nginx
HAProxy
AWS
Azure
Google Cloud
DevOps
CI/CD Pipelines
GitHub Actions
GitLab CI
Containerization
Monitoring
Logging
Auto Scaling
Production Deployment
Release Management
Monitoring
Prometheus
Grafana
Loki
Alerting
Health Checks
Performance Optimization
Architecture & Technical Leadership
I frequently work as a technical lead and solution architect.
Services include:
Solution Architecture
Software Architecture
System Design
Database Design
API Architecture
Microservices
Event-driven Architecture
Multi-tenant Architecture
High Availability
Disaster Recovery
Security Architecture
Performance Optimization
Documentation & Project Delivery
Beyond engineering, I help clients organize and successfully deliver projects.
I prepare:
Software Architecture Documents
Technical Design Documents
API Documentation
Swagger / OpenAPI Specifications
Statements of Work (SOW)
Functional Specifications
BRD
PRD
Deployment Guides
Infrastructure Documentation
QA Plans
Technical Proposals
Project Estimates
Delivery Roadmaps
I also work comfortably with:
Jira
ClickUp
Trello
Azure DevOps
GitHub Projects
Linear
Confluence
Notion
Recent Projects
Enterprise Multi-tenant CCaaS Platform
AI Voice Agent using OpenAI Realtime API
Telecom ERP Platform
Hosted PBX Platform
FusionPBX Custom Development
FreeSWITCH Call Routing Engine
Enterprise AI Knowledge Platform
AI Workflow Automation
CRM Integrations
Telecom Billing Platform
WebRTC Calling Platform
Call Center Analytics Dashboard
Healthcare Communication Platform
Law Firm AI Automation
Customer Support Automation Platform
Why Clients Hire Me
✔ 20+ years of software engineering experience
✔ 90+ successful Upwork projects
✔ End-to-end ownership from architecture to production
✔ Full-stack development across frontend, backend, APIs, databases, AI, and cloud infrastructure
✔ Deep expertise in FreeSWITCH, Asterisk, FusionPBX, SIP, WebRTC, CCaaS, and UCaaS
✔ Production AI engineering using OpenAI, Claude, Gemini, LangChain, Lang
Steps for completing your project
After purchasing the project, send requirements so Pankaj can start the project.
Delivery time starts when Pankaj receives requirements from you.
Pankaj works on your project following the steps below.
Revisions may occur after the delivery date.
Requirements Gathering
Define use case, business goals, and user flows Confirm number of call intents or flows Gather CRM details (e.g. GoHighLevel API access) Select preferred STT (Whisper/Deepgram) TTS (Polly/ElevenLabs), and hosting approach
Account & API Setup
Get access to Twilio, OpenAI, GoHighLevel, n8n, and optionally AWS or ElevenLabs Share client branding assets (logo, color codes, greeting lines)