Hire the Best PhoneGap Developers

I am a VoIP and Telephony Engineer with extensive experience in 3CX, VICIdial, Asterisk, FreeSWITCH, Twilio, SIP Trunking, and DID number provisioning. I help businesses build, optimize, and maintain reliable communication systems for call centers, telemarketing operations, and enterprise telephony environments. My expertise includes PBX installation and configuration, SIP trunk integration, number porting, IVR design, call routing, predictive dialer setup, inbound and outbound call center solutions, and VoIP troubleshooting. I am also experienced with Linux server administration, cloud deployments, and API integrations for voice and SMS applications. Whether you need a complete call center deployment, 3CX configuration, VICIdial optimization, Twilio integration, SIP troubleshooting, or ongoing telephony support, I can deliver scalable and dependable solutions tailored to your business needs. Core Skills: • 3CX PBX Administration • VICIdial Installation & Management • Asterisk & FreeSWITCH Development • Twilio Voice & SMS Solutions • SIP Trunk Configuration • DID Number Provisioning & Porting • Predictive & Power Dialers • IVR & Call Flow Design • Linux Server Administration • VoIP Troubleshooting & Optimization • CRM & API Integrations • Call Center Infrastructure Setup I focus on delivering reliable communication systems that improve efficiency, call quality, and business performance. 3CX, VICIdial, Asterisk, FreeSWITCH, Twilio, VoIP, SIP, SIP Trunk, DID Numbers, PBX, IP PBX, Hosted PBX, Cloud PBX, Telephony, Telecom, Telecommunications, Call Center, Contact Center, Predictive Dialer, Power Dialer, Auto Dialer, Progressive Dialer, Call Routing, IVR, Interactive Voice Response, Call Queue, Ring Groups, Voicemail, Call Recording, Number Porting, SIP Carrier, Voice Gateway, Session Border Controller, SBC, WebRTC, SMS Gateway, Twilio Voice, Twilio SMS, Twilio API, Linux Administration, CentOS, Ubuntu, Debian, Rocky Linux, AlmaLinux, MySQL, MariaDB, PostgreSQL, Apache, Nginx, SSH, VPN, Firewall, Networking, TCP/IP, UDP, RTP, QoS, NAT Configuration, VoIP Troubleshooting, SIP Debugging, SIP Trace, Wireshark, CRM Integration, Salesforce Integration, HubSpot Integration, Zoho CRM, Pipedrive, API Integration, REST API, PHP, Python, Bash Scripting, AGI Scripts, Call Flow Design, Inbound Calling, Outbound Calling, Lead Management, Telemarketing, Cold Calling Systems, Voice Broadcasting, Bulk SMS, DID Provisioning, SIP Registration, Carrier Integration, Call Monitoring, Queue Management, Agent Management, Multi Tenant PBX, Failover Configuration, High Availability, Cloud Deployment, AWS, DigitalOcean, Vultr, Linode, Dedicated Servers, VPS Setup, Server Migration, System Optimization, VoIP Security, Fraud Prevention, FreePBX, Issabel PBX, FusionPBX, Elastix, Yeastar, Grandstream, Fanvil, Yealink, Polycom, Cisco VoIP, Sangoma, OpenSIPS, Kamailio, Voice API, Telecom Consulting, Call Center Setup, VoIP Engineer, Telephony Engineer, SIP Expert, 3CX Expert, VICIdial Expert, Twilio Expert, Asterisk Expert, FreeSWITCH Expert, Linux Server Administrator, Network Engineer, Technical Support, System Administration, Remote Support, Cloud Communications, Unified Communications, UCaaS, Business Phone System, Enterprise Telephony, Call Center Optimization, Dialer Configuration, Lead Campaign Management, Real Time Reporting, Call Analytics, Voice Solutions, Telecom Infrastructure, Contact Center Solutions, VoIP Deployment, PBX Installation, SIP Configuration, DID Management, Call Center Technology, Telecom Solutions

I develop high-performance hybrid mobile applications that deliver reliable results in real-world environments, including Firebase integrations, push notifications, custom native plugins, and complex SDK integrations. With 14+ years of experience and over 200 successfully delivered projects, I specialize in building, optimizing, and maintaining Android and iOS applications using Ionic, Cordova, Capacitor, Vue.js, and React Native. I help businesses launch scalable, cost-effective mobile solutions and solve critical issues that other developers struggle to fix. My expertise includes app stabilization, performance optimization, native SDK integration, App Store compliance, and troubleshooting complex mobile application challenges. ### What I Can Do for You ✔ Develop cross-platform mobile applications (Android & iOS) from scratch ✔ Convert existing websites or web applications into mobile apps ✔ Develop custom Cordova and Capacitor plugins ✔ Integrate native iOS and Android SDKs into Ionic applications ✔ Diagnose and resolve crashes, bugs, and performance bottlenecks ✔ Upgrade legacy applications (Cordova → Capacitor migration) ✔ Integrate APIs, Firebase services, and third-party platforms ✔ Resolve App Store and Google Play review and deployment issues ✔ Optimize application speed, stability, and user experience ### Technical Expertise • Ionic Framework (Angular & Vue) • Apache Cordova & Capacitor • Vue.js & React Native • JavaScript, TypeScript, HTML5, CSS3 • Native Android (Java/Kotlin) • Native iOS (Swift/Objective-C) • Firebase (Authentication, Firestore, Analytics, Push Notifications) • REST APIs & Third-Party Integrations • WebView Optimization & Plugin Debugging ### Specialized SDK & Plugin Development • Custom Cordova Plugin Development • Custom Capacitor Plugin Development • Native SDK Bridging for Ionic Applications • Microblink BlinkID Integration • Passport, Driver's License & ID Card Scanning • Selfie Verification & Face Matching • OCR & Document Data Extraction • Barcode & QR Code Scanning • Camera & Media Processing Integrations • Biometric Authentication • Payment Gateway SDK Integrations • Push Notification SDK Integrations One of my key specialties is developing custom native plugins for Ionic, Cordova, and Capacitor applications. I have successfully built and integrated complex SDKs, including Microblink BlinkID, enabling passport scanning, driver's license scanning, ID card recognition, selfie matching, and OCR-based data extraction on both Android and iOS. When a required SDK does not have an existing plugin, I can build the complete native bridge and integration from scratch. ### Why Clients Work With Me • Strong expertise in solving complex mobile application issues • Advanced debugging skills across native and hybrid environments • Extensive experience with plugin development and SDK integrations • Clear communication and reliable delivery • Proven track record with production-grade and long-term projects If your application is experiencing crashes, performance issues, SDK integration challenges, App Store rejections, or deployment problems, I can quickly identify the root cause and implement a reliable solution. From concept → development → deployment → scaling, I manage the complete mobile application lifecycle. Available to start immediately.

Most businesses lose leads because calls go unanswered, follow-ups happen too late, or staff spend too much time handling repetitive inquiries. I provide fully managed AI voice automation systems that answer calls, recover missed calls, qualify leads, and handle outbound calling conversations on behalf of your business. These are not chatbots. These are AI-powered voice agents that can hold natural conversations, collect information, qualify prospects, and automatically organize lead data for your team. Services I Provide: ✓ AI Receptionist (24/7 Incoming Call Handling) ✓ Missed Call Recovery (Instant AI Callback & Lead Qualification) ✓ Outbound AI Calling Agents (Lead Follow-Up & Prospect Qualification) ✓ Appointment Booking & Inquiry Handling ✓ Lead Intake & Customer Information Collection ✓ CRM & Database Integration ✓ Call Recording, Transcripts & Reporting ✓ Automated Lead Routing & Follow-Up Workflows Ideal For: • Real Estate Investors & Agencies • Law Firms • Medical & Dental Clinics • Home Service Businesses (HVAC, Roofing, Plumbing, Solar) • Insurance Agencies • Marketing Agencies • Local Service Businesses How The System Works: 1. AI answers incoming calls or places outbound calls. 2. AI asks customized qualifying questions based on your business needs. 3. Lead details, call summaries, and transcripts are captured automatically. 4. Information is delivered to your CRM, database, or Google Sheets. 5. Your team receives organized and qualified opportunities ready for follow-up. Important: I operate on a managed service model. Clients do not receive backend access or ownership of the automation infrastructure. I handle the setup, hosting, integrations, monitoring, optimization, maintenance, and ongoing improvements. This ensures maximum reliability, continuous performance monitoring, and a hands-off experience for the client. My goal is simple: help businesses answer more calls, qualify more leads, and capture more revenue without hiring additional staff or missing opportunities. If you're looking for a reliable AI calling solution that is fully managed and continuously maintained, let's discuss your business requirements.

👋 Hi, I’m Oleksii - a Twilio expert with over 7 years of hands-on experience building scalable, real-time communication systems using the full Twilio stack: 📞 Programmable Voice / SMS, 🧠 TaskRouter & Flex, 🎛️ Studio, Functions, Conversations, Sync, Webhooks and more. I’ve successfully completed 120+ Twilio projects on Upwork, including: • Eliminating latency issues in phone calls 🔧 • Creating SMS marketing automation pipelines 📲 • Developing full-scale Flex dashboards with custom workflows 🧩 Clients describe me as: “Very skilled, excellent communicator, smart guy and a pleasure to deal with.” “Oleksii was very helpful and available :) We no longer have problems with latency during our phone calls.” 🛠 Whether you need help with: • Twilio Studio call flows • Complex webhook-based automation • TwiML, IVR, call forwarding setups • Integrating Twilio with CRMs or internal systems • Building voice/SMS logic in Node.js, Laravel, or Firebase environments …I’ve got you covered. Let’s bring your Twilio-powered solution to life 🚀 Feel free to invite me to your job or message me with questions.

✅ 12+ Years in Mobile Development 🏆 Top Rated | Kotlin, iOS, SDKs, BLE, VoIP & System-Level Android Apps I help businesses build stable, production-ready Android/iOS applications designed for long-term reliability, scalability, and real-world usage. Over the last 12+ years, I’ve worked on Android/iOS apps ranging from consumer products to enterprise systems, including VoIP platforms, Android SDKs, BLE integrations, location tracking systems, streaming apps, and custom Android OS-level features. My focus is building and maintaining Android/iOS systems that remain stable, maintainable, and performant over time. 🚀 What I can help you with: ✅ Native Mobile App Development (Kotlin & iOS) ✅ Android SDK Development & Integration ✅ BLE (Bluetooth Low Energy) Applications ✅ VoIP, Audio/Video Calling & Streaming Apps ✅ Background Services & Foreground Services ✅ Existing App Maintenance & Bug Fixing ✅ Play Store Release & Compliance ✅ Performance Optimization & Stability Improvements ✅ Custom Android OS / System-Level Features ✅ Long-Term Product Development & Support ⚙️ Core Android Expertise: ✔ Jetpack Compose & Modern Android Architecture ✔ MVVM, Clean Architecture & Modular Codebases ✔ Firebase, Firestore & Realtime Systems ✔ REST APIs, WebSockets & SignalR ✔ Google Maps & Real-Time Location Tracking ✔ Media Streaming & Real-Time Communication ✔ Offline Storage & Sync Solutions ✔ Push Notifications & Background Processing ✔ In-App Purchases & Subscription Systems ✔ Kiosk Mode & Device Management 🔥 Specialized Experience: ✔ Android SDK development used across multiple applications ✔ BLE communication & external device integrations ✔ WebRTC, Twilio & Linphone integrations ✔ Enterprise Android systems with long-term maintenance ✔ Performance-critical and reliability-focused Android apps 🏢 Some Projects & Domains Worked On: ✔ Spirit Airlines ✔ Santander UK ✔ Plickers ✔ Ringplan VoIP ✔ Tracking & Logistics Applications ✔ Enterprise Cargo & Retail Systems I personally oversee projects from architecture to final delivery. For larger engagements, I collaborate with my in-house team of 25+ developers across Android, iOS, Flutter, backend, QA, web, and DevOps - giving clients a single point of contact backed by complete execution support. If you're building a new Android/iOS product, scaling an existing app, or solving complex Android/iOS issues, feel free to message me. Happy to review your app or requirements before we start.

I build, scale and rescue production VoIP and Voice AI platforms. For over 15 years, I've been designing SIP, WebRTC and real-time communication systems built on FreeSWITCH, OpenSIPS, Asterisk and related technologies. My experience ranges from troubleshooting complex SIP and media issues to designing multi-tenant communication platforms, AI-powered voice systems and carrier-grade telephony infrastructure. I can help with: • AI Voice Agents and Voice AI Platforms • OpenAI Realtime, Gemini Live, Deepgram, ElevenLabs, RetellAI • FreeSWITCH and Asterisk development • OpenSIPS and Kamailio SIP routing • SIP trunking and carrier integrations • WebRTC platforms and browser telephony • RTP, NAT traversal and media troubleshooting • SBC design and deployment • Contact center and call center solutions • Twilio, Telnyx and CPaaS integrations • Production incident investigation and VoIP troubleshooting • Telephony migrations and system modernization My technical background includes: • VoIP: SIP, RTP, WebRTC, FreeSWITCH, OpenSIPS, Kamailio, Asterisk, Jambonz, Drachtio, Twilio, Telnyx • Backend Development: Node.js, TypeScript, Python, Go, C • Databases: PostgreSQL, MySQL, MongoDB, Redis • Messaging: RabbitMQ, AWS SQS • Cloud & Infrastructure: AWS, GCP, Docker, Kubernetes, Linux, CI/CD • Monitoring: Prometheus, Grafana, ELK Stack Recent projects include: • AI-powered voice agents integrated with telephony platforms • SIP and WebRTC infrastructures handling production traffic • Multi-tenant communication platforms for SaaS products • Carrier integrations and custom call routing solutions • Real-time communication systems built on FreeSWITCH, OpenSIPS and cloud-native infrastructure Whether you need to build a new platform, migrate an existing system, integrate Voice AI capabilities or resolve complex SIP/WebRTC issues, I can help deliver a reliable production-ready solution.