✅ Top Rated Plus AI Agent Development
✅ 100% Job Success Score
✅ Fluent English Verified
AI Voice Agents | Twilio Expert | SMS, Calling & CRM Automation
I help businesses automate customer communication using AI Voice Agents, SMS Automation, Calling Systems, CRM Integrations, and Communication Workflows.
With 130+ completed projects, Top Rated Plus status, and a 100% Job Success Score, I specialize in building production-ready systems that answer calls, qualify leads, book appointments, automate follow-ups, improve customer response times, and reduce manual work.
My expertise combines modern AI technologies with real-world communication infrastructure, helping businesses move from manual processes to scalable automation.
𝗖𝗼𝗿𝗲 𝗘𝘅𝗽𝗲𝗿𝘁𝗶𝘀𝗲
📞 Voice AI & Communication Automation
AI Voice Agents, AI Receptionists, AI Calling Systems, Appointment Booking Agents, Lead Qualification Systems, Customer Support Automation, Contact Centers, IVR Systems, SIP, SMS Automation, Call Routing
🤖 AI Solutions & Conversational Systems
OpenAI, Claude, Gemini, Vapi, Retell AI, Conversational AI, Knowledge Assistants, Internal AI Tools, Business Automation
⚙️ CRM & Workflow Automation
Lead Management, Pipeline Automation, Customer Communication Workflows, CRM Integrations, Automated Follow-Up Systems
𝗦𝗲𝗿𝘃𝗶𝗰𝗲𝘀
📞 AI Voice Agents & Calling Systems
• AI Receptionists
• AI SDRs
• Appointment Booking Agents
• Customer Support Agents
• Outbound Calling Systems
• Inbound Voice Automation
• Voice AI Integrations
📡 Twilio & Communication Solutions
• Twilio Development
• SMS Platforms
• IVR Systems
• Call Center Solutions
• Twilio Flex
• Voice & Messaging Automation
• Toll-Free & A2P 10DLC Solutions
⚙️ CRM & Business Automation
• HubSpot Integrations
• GoHighLevel Automation
• Salesforce Integrations
• Custom CRM Development
• Lead Qualification Workflows
• Business Process Automation
🧠 OpenAI, Claude & AI Integrations
• ChatGPT Solutions
• Claude Integrations
• AI Assistants
• Knowledge Systems
• Internal AI Tools
• RAG Applications
📱 SaaS, Web & Mobile Applications
• Customer Portals
• Admin Dashboards
• AI-Powered Platforms
• Web Applications
• Mobile Applications
🖥️ Backend Development
Python, Node.js, FastAPI, Express.js, REST APIs, Webhooks, Microservices
💻 Frontend Development
React, Next.js, Vue.js, Angular
📱 Mobile Development
React Native, Flutter, Swift, Kotlin
☁️ Cloud & Infrastructure
AWS, Azure, GCP, Docker, CI/CD, Serverless Architectures
📊 Databases & AI Infrastructure
PostgreSQL, MongoDB, Firebase, Supabase, Vector Databases
𝗜𝗻𝗱𝘂𝘀𝘁𝗿𝗶𝗲𝘀
• Real Estate & Property Management
• Healthcare & Wellness
• LegalTech
• Financial Services
• Logistics & Transportation
• Professional Services
• Call Centers
• Home Services
• SaaS & Technology Companies
If you're looking to automate calls, SMS, customer communication, lead qualification, appointment booking, or customer support using AI and Twilio-based communication systems, let's discuss your project.
Keywords:
AI Voice Agent, AI Receptionist, AI Calling Agent, Twilio Developer, SMS Automation, IVR Development, CRM Automation, Voice AI, OpenAI, Claude, Vapi, Retell AI, Contact Center Solutions, Call Center Automation, Lead Qualification, Appointment Booking, Customer Communication Automation, Workflow Automation, Conversational AI, SaaS Development, Python, Node.js, React
Twilio
Twilio API
SMS
SMS Gateway
WhatsApp
SMS Module Optimization
API Development
VoIP
VoIP Software
Telephone System
IVR Software
Call Center Software
Automated Call Distribution
Chat & Messaging Software
Chatbot Development
AI Chatbot
AI Bot
CRM Automation
Automation
Compliance
Devendra Kumar S.
Gurgaon, India
$35/hr
4.7
17 jobs
I am a VoIP and cloud technologies expert with over 12 years of experience specializing in Asterisk, FreePBX, Issabel, WebRTC, and cloud deployments. I have successfully implemented, customized, and optimized PBX systems and real-time communication solutions for businesses of all sizes.
Whether it’s configuring a robust VoIP infrastructure, integrating WebRTC, or deploying PBX systems on the cloud, I deliver reliable and scalable solutions tailored to client needs. I am committed to providing high-quality work and timely results.
I look forward to contributing to the success of your project.
Best regards,
Devendra Soni
Asterisk | FreePBX | VoIP | WebRTC | Cloud Specialist
FreeSWITCH
VoIP Administration
Elastix
Asterisk
FreePBX
Linux System Administration
WebRTC
VICIDIAL
Twilio
VoIP PBX
VoIP Software
VoIP
AI Bot
Call Center Software
ElevenLabs
Gaurav L.
Bhopal, India
$24/hr
4.7
219 jobs
I help businesses build reliable, scalable communication systems and web applications by combining deep expertise in VoIP (3CX & Yeastar) with full-stack development and API integrations.
With 6+ years of experience in 3CX, hands-on expertise in Yeastar Cloud PBX, and 3+ years in full-stack development, I specialize in delivering end-to-end solutions — from telephony infrastructure to CRM integrations and custom dashboards.
🔥 What I Can Do For You
☎️ VoIP & PBX Solutions (3CX + Yeastar)
3CX setup, configuration & troubleshooting (V18/V20)
Yeastar Cloud PBX deployment & management
SIP Trunk integration (Twilio, Telnyx, Flowroute, etc.)
IVR, Call Queues, Ring Groups, Call Routing
Predictive / Progressive Dialer setup
Call recording, reporting & analytics
Multi-tenant PBX architecture
DID management & call flow optimization
💻 Full Stack Development
Backend: PHP, Node.js, Golang
Frontend: JavaScript, HTML, CSS, Bootstrap, Tailwind
Database: MySQL, PostgreSQL
Build scalable CRM systems & dashboards
WebRTC / SIP dialer development
Real-time systems & automation workflows
🔗 API Development & Integrations (Swagger/OpenAPI)
REST API design & development
Swagger/OpenAPI documentation
CRM integrations (Zoho, Salesforce, Monday, etc.)
Webhooks, automation, and data sync systems
🌐 WordPress Development
Custom theme & plugin development
Website optimization & speed improvements
API integrations with WordPress
Business websites & landing pages
💡 Why Clients Choose Me
✔ 6+ years in VoIP & telephony systems
✔ Strong backend + infrastructure understanding
✔ Fast troubleshooting & problem-solving
✔ Clean, scalable, production-ready solutions
✔ Excellent communication & long-term support
📌 Recent Work Highlights
Built multi-company 3CX dialer system with CRM integration
Deployed Yeastar Cloud PBX for international clients
Developed VoIP analytics dashboards & call tracking systems
Integrated Twilio / Telnyx with custom applications
Created API-driven automation workflows using webhooks
🎯 Let’s Work Together
If you need help with:
Setting up or fixing your 3CX / Yeastar PBX
Building a custom dialer or VoIP system
Integrating APIs or CRM systems
Developing a scalable web application
👉 Send me a message — I’ll provide a clear solution quickly.
PHP
Python
JavaScript
Telecommunications
Full-Stack Development
VoIP PBX
Call Center Management
3CX
System Administration
API Integration
HubSpot
API Development
API
Pipedrive
WordPress
Pankaj K.
Delhi, India
$45/hr
4.9
113 jobs
Principal Full-Stack Platform Architect | Telecom, AI Voice, SaaS & Cloud
I help startups, telecom providers, BPOs, enterprises, and SaaS companies 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
FreeSWITCH
Solution Architecture
VoIP Software
VoIP Administration
VoIP PBX
Asterisk
VICIDIAL
FreePBX
Session Initiation Protocol
Call Center Software
CRM Automation
Full-Stack Development
AI Agent Development
AI App Development
OpenAI Codex Prompt
Large Language Model
OpenAI API
Docker
NestJS
Terraform
Nimit P.
Ahmedabad, India
$20/hr
4.8
26 jobs
Hi Guest,
First of all, thanks for visiting our profile.
I am doing freelancing since 2010 and my expertise on complete VoIP solution including Freeswitch, Asterisk, PJSip, Opensips and Kamailio. I just recently launched a company which is not offering only VoIP solution but Zeus in Web Development(PHP, WordPress etc), Mobile App Development(Android & iOS).
We are a team of members having extensive knowledge of all the services we are offering. We have successfully completed many projects delivered competent results with 100% accuracy with lifetime free support.
To keep in mind 100% availability, Our dedicated manager is always online to make sure our client will face no more difficult to ask any query at any time. Let me mentioned the technologies which are our core strength listed below:
- Development of Linphone Mobile VoIP Diallers
- Development of PJSIP Mobile VoIP Diallers
- Installation, development, customization, and maintenance of Asterisk,FreeSwitch Switch,Kamalio and OpenSIPs Servers
- Android app development
- iOS app development
- Flutter Cross Platform App Development
- Electron App Development
- Web application development
- ReactJS and ReactNative development for web and mobile applications
- Testing and bug fixing for existing applications
Consulting for ongoing projects
Project consulting for Android, iOS, ReactJS, Asterisk, FreeSwitch, OpenSIPs, Kamailio, ASTPP, RTPengine, MediaProxy, RTPproxy, FreePBX, and A2Billing
Expertise in developing Flutter WebRTC applications
Expertise in developing ReactNative WebRTC applications
Our price is very reasonable which allows us to work with us. Please share your requirement today only with us to check our capabilities to take your experience on the next level.
To name a few tools & technologies that I have worked on:
• High-level languages: C++, Objective C, Java, Python, PHP
• IDEs: Xcode, Android Studio, Eclipse
• Version Control & CI: SVN, Git, Perforce, Bitbucket, Jenkins
• DBMS: MS SQL, MySQL, Oracle, PostgreSQL, MongoDB
• Frameworks: Django, Zend, Magento, Django REST
• Management tools: VersionOne, Jira, Trac, MS Project, MS Visio, XMind, Bugzilla, Balsamiq
• Amazon Web Services (AWS) - EC2, S3, SQS, SNS, RDS, CloudTrail, Cloudfront
FreeSWITCH
PHP
WordPress
VoIP Administration
Asterisk
Session Initiation Protocol
VoIP
FreePBX
iOS Development
VoIP Software
Android App Development
iOS
WebRTC
VICIDIAL
Call Center Management
Sahil G.
Ambala, India
$21/hr
4.4
64 jobs
👋 Hi, I’m Sahil- a Twilio expert with over 11+ years of hands-on experience building scalable, real-time communication systems using the full Twilio stack and AI-powered tools.
📞 Programmable Voice / SMS,
🧠 TaskRouter & Flex,
🎛️ Studio, Functions, Conversations, Sync, Webhooks and more.
I design and implement AI-powered calling platforms, autonomous voice agents, conversational IVR systems, SMS and WhatsApp automation, and cloud contact centers. My work focuses on reliability, low latency, and real-world scalability for high-volume production environments.
My core expertise includes Twilio Programmable Voice, SIP, Asterisk, FreeSWITCH, WebRTC, and AWS Connect. I build advanced call flows with features such as call recording, real-time transcription, sentiment analysis, intelligent routing, and live analytics.
I specialize in AI-driven voice systems, including outbound and inbound AI calling, agent assist, call summarization, intent detection, and conversational call handling using modern AI frameworks integrated with telephony platforms.
On the messaging side, I build compliant SMS and WhatsApp automation systems, including A2P 10DLC workflows, notifications, chatbots, and CRM-integrated messaging pipelines.
I also design and customize cloud contact centers using AWS Connect and Twilio Flex, including omnichannel routing, agent dashboards, reporting, and migrations from legacy PBX or call center systems.
My technical stack includes Node.js, PHP, Laravel, React, Next.js, JavaScript, MySQL, Firebase, Linux, REST APIs, SIP, and WebRTC.
Clients work with me to build AI voice agents, automate call centers, scale VoIP infrastructure, and integrate voice and messaging into SaaS products and internal systems. I prioritize clear communication, clean architecture, and long-term maintainability.
Thank you
FreeSWITCH
Twilio API
VoIP
AI Chatbot
Asterisk
Call Center Software
IVR Software
Make.com
n8n
Webflow
Claude
Agent GPT
AI Agent Development
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