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- UTILIZING AI TECHNOLOGIES FOR THE DEVELOPMENT, TESTING, OPTIMIZATION, AND INTEGRATION OF PRE-EXISTING VOIP SYSTEMS WITH EXTERNAL SERVICES AND PLATFORMS. - I have more than 16 years to work as system administrator, deploy server, maintenance system base on: asterisk, voip, avaya, freeswitch, kamailio, opensip..... - Developed many VOIP solutions, system for customer over the world as: voicemail system, conference systems, IVR systems, calling card system. - Django developer: Develop e-commercial sites, CMS sites, API systems and more - AngularJS developer, one page applications. - etc.

Senior full-stack engineer building production SaaS platforms and AI-driven backends. .NET, C#, ASP.NET Core, Python, FastAPI, Node.js, Angular, React, TypeScript. 9+ years, Top Rated, 100% Job Success. Need a backend that ships and stays up, plus a frontend your users actually want to use? That is the work I do. I own the whole thing: architecture, REST and GraphQL APIs, multi-tenant data, payments, real-time, cloud, and CI/CD, including the reliability work most people skip. I build systems that hold under real load, not prototypes that break in week two. Systems I designed and built: RoverDent, a multi-tenant dental and healthcare SaaS. Nine .NET 8 microservices behind a React 18 dashboard, with Temporal running multi-day patient follow-up so call, SMS, email, and WhatsApp sequences never lose state. Two services are Python FastAPI: a LiveKit real-time voice AI agent, and a conversation API doing AWS Cognito RS256 token verification and WebSocket chat. Stripe and Twilio in production, HIPAA-aware audit trails, field-level isolation and RBAC across tenants. VisionONE, an enterprise ERP and payroll platform. .NET 8 with a dual-ORM strategy: EF Core for the domain model and Dapper for heavy accounting and ledger queries where read performance matters. Angular 20 frontend with NgRx and AG Grid Enterprise for data-dense payroll views. Real-money disbursement through Lipa Na M-Pesa STK Push with webhook callbacks and transaction-status polling, so payment state stays correct end to end. Hangfire for background salary runs, TOTP two-factor auth across multiple SQL Server databases. SmartStay, a multi-tenant hotel and property management SaaS. ASP.NET Core 8 on the ABP framework with an Angular 17 front end. Stripe and PayPal behind PCI-ready Azure infrastructure (VNet, WAF, NSG), SignalR pushing live room-status and reservation updates, GraphQL for flexible queries, Redis caching, and Power BI dashboards for managers. What I help clients build: Multi-tenant SaaS with RBAC, tenant isolation, and secure architecture REST and GraphQL APIs, microservices, CQRS, clean architecture Modern frontends: Angular (NgRx, AG Grid), React, TypeScript, responsive UIs Payments and billing: Stripe, PayPal, Authorize.Net, M-Pesa, webhook handling and signature verification Real-time features: SignalR, WebSockets, MQTT, event-driven backends AI and LLM integration: OpenAI, voice agents, automation with n8n and Temporal Cloud and DevOps: AWS, Azure, Docker, GitHub Actions, Azure DevOps, CI/CD pipelines Legacy modernization: .NET Framework to .NET 8 migrations, desktop to web Core stack: Backend: C#, ASP.NET Core, .NET 8/9, Python, FastAPI, Node.js Frontend: Angular, React, Next.js, TypeScript, Blazor, NgRx Data: PostgreSQL, SQL Server, Redis, Cosmos DB, EF Core, Dapper Cloud: AWS, Azure, Docker, CI/CD Integrations: Stripe, Twilio, SendGrid, WhatsApp, Shopify, OpenAI How I work: I learn a codebase deeply, communicate clearly about risk and tradeoffs, and give honest timelines with no surprises mid-project. I do my best work on long engagements where reliability matters and you want someone you can hand a hard problem to and trust it gets shipped. Tell me what you are trying to ship and your current stack. I will tell you straight whether I am the right fit and how I would start. Happy to do a quick call through Upwork.

Computer professional with more than 9 years of experience in modern approaches for web, mobile and infrastructure development. Core skills: ✔ JavaScript(ES5, ES6, ES7), TypeScript, Angular(2-11), Ionic, NextJS ✔ Twilio SIP Trunking and Media Integration ✔ VAPI and ElevenLabs Voice Agents integration with Live Telephony Calls ✔ AWS SQS, SNS, EC2, Rabbit MQ, Web Sockets, Stripe, sFox, Algolia, PayCaddy ✔ MongoDB, PostreSQL ✔ Node.js, ExpressJS, NestJS ✔ ICE Servers, Media Servers ✔ WebRTC

15+ years in Software Development Available for 40 hrs/wk Excellent references from CEOs of the companies I worked for/with Able to bring a product to the market from inception, through specification, architecture, design, and implementation and testing. Seeking for software development projects in the following areas: - Desktop applications - Client/Server systems - Web applications Technologies and Frameworks: - C++, C#/VB.NET, Java, React, Node.js/React.js, MFC/ATL/COM, Office OM/JS API, MSGraph, WinForms, WPF, DevExpress, NetAdvantage Infragistics, XML, JSON, WebServices (WCF, RESTFull), SQL, Entity Framework, sockets (.NET and Winsock), JQuery/AngularJS/Bootstrap, etc

🎯14+ Years of Experience | 75+ Projects Delivered | SaaS, Logistics, eCommerce, Enterprise | Technical Writing | AI Chatbot I’m a results-driven software architect and creative web designer with over 14 years of experience delivering full-scale solutions alongside Product Managers across web, cloud, and mobile platforms. I also bring hands-on experience in logistics and transportation systems, including end-to-end development of TMS (Transport Management System) and WMS (Warehouse Management System) platforms. This includes shipment booking and dispatching, route planning, fleet and carrier management, warehouse inventory control, order lifecycle management, and real-time tracking systems using GPS and event-driven architecture. 🛠 Core Development Expertise • .NET (.NET Core, MVC, Web API), C#, Java, Spring Boot, Tailwind, Technical Writing • SaaS architecture, Logistics platforms, TMS, WMS, Fleet Management, Route Optimization, Supply Chain Systems, Ethereum, Solidity, Blockchain, Blockchain Architecture • Real-time tracking using WebSockets,,Opencart, GPS integrations, live data streaming, and event-driven systems • PostgreSQL, SQL Server, MySQL, MongoDB, Redis, ClickHouse • OpenAI, Generative AI, Machine Learning, OCR, Airtable, Workflow Automation • Angular, Next. js (App Router), React. js, TypeScript, Blazor, JavaScript • REST APIs, GraphQL, API integrations, OAuth, Webhooks • Cloud & DevOps: AWS, Azure, CI/CD pipelines, EntraID, Terraform, S3-compatible storage • Backend: .NET, Node. js, Golang, Python (Django / FastAPI) • ERP/CRM integrations: Zoho, HubSpot, Monday. com, Fedex • Payments & Finance: Stripe API, QuickBooks API, Intuit integrations • Logistics-specific modules: Shipment booking, load management, driver portals, customer/carrier dashboards, warehouse operations, inventory tracking, reporting & analytics dashboards 🎨 Design Skillset • Figma, Webflow, Adobe Creative Suite • Mobile-first, CRO-focused UI/UX for SaaS and logistics platforms • Wireframes, prototypes, and high-fidelity designs aligned with operational workflows Whether you’re building a scalable logistics SaaS platform, transportation management system, or a warehouse automation solution, I can step in from architecture to execution and deliver a system that is performant, scalable, and built for real-world operations. 📍 Based in India | Strong experience with US-based logistics clients | Time zone alignment is not an issue | Open to short- and long-term projects

Top 1%; part of the UpWork's Expert-Vetted program. ✅More than 100 completed projects on UpWork 🇺🇸Available for calls during business hours 🎓4 AWS Certifications: Professional Solutions Architect (result is 945 out of 1000), Professional DevOps Engineer (915), Machine Learning Specialty, Cloud Practitioner In short, the solutions I created are used by millions of users every day. I could build a web, mobile or desktop application using Serverless Computing, conforming to the principle of the least privilege under version control for each function (Pay-per-use AWS or Google Cloud infrastructure that scales indefinitely). When I code either the Frontend or Backend solutions, the experience I have defined the prioritization of the characteristics for the product: 1. Simplicity (readability). ---- all frontend services I create are event-driven with the FaaS infrastructure or in rare cases BaaS. ---- I write in strict TypeScript (if you don't know TypeScript, it is the same JavaScript plus type safety to increase stability). 2. Technical scalability ---- Comparing to containerized microservices, where parts are connected to each other, FaaS development allows to create completely independent functions. It is easier to manage and to make changes as you split the functionality into much smaller blocks. ---- FaaS can scale indefinitely, so any load the cloud provider (such as AWS) could handle is supported. -------- If you have 0 customers today, your bill is $0, comparing to microservices, where you have to have at least one container running $25/month. A typical project is eight containers. -------- If you have a billion customers tomorrow, FaaS auto scales horizontally to handle the new load automatically, with the pricing of an optimized solution close to $2-5/million requests for ALL infrastructure combined. 3. Size ---- The size of the bundled assets needs to be small as it affects the operating costs (you are charged by millisecond). ---- I have created tens of different custom Webpack solutions for all types of possible cases to minimize and optimize the bundles, including code splitting, tree shaking, finding the most appropriate target for the JavaScript (or TypeScript transpilation), image minification and lazy-loading (PNG, JPEG, SVG, etc), service workers, manifest, etc. -------- and even the updating process of the objects in a file hosting (such as AWS S3) to upload only those assets that have changed. -------- I have worked on many projects, every time trying to find something else to improve, so the solutions are extremely well optimized. 4. Performance ---- when I had projects to optimize for performance, I have created a lot of custom solutions as public solutions are for everyone and, therefore, typically suboptimal for a particular case. I create SPAs, conforming to PWA standards, and frontend plugins using React.js. I follow Component Driven Development (CDD) together with Visual Test Driven Development. For that, I use PlayWright and Storybook. When writing styles, I use CSS-in-JS (primarily using Emotion library). The Desktop app development involves also Electron, but the overall process is the same. That is the reason why it is easy to convert my solutions to distribute as a desktop app. When creating mobile apps, I use either React Native or create hybrid web-based solutions with Capacitor.js. 🔒Backend: I am a strong proponent of Serverless Computing, who has extensive experience with FaaS and BaaS, automatically generating IAM rules and cloud services, and conforming to the principle of the least privilege for each function/service. In regards to HTTP APIs, I create: - RESTful APIs covering them in tests and preparing for adoption by frontend devs via password-protected documentation over web endpoints where the frontend devs are able to observe and interact with Swagger UI that conforms to the OpenAPI 3.0 specification. - GraphQL. Created in all possible ways: custom with plain GraphQL library (no Apollo or other wrappers), with Apollo; in Programmatic and Declarative ways I automate provisioning of infrastructure (IaC) using AWS CDK and Google Deployment Manager configs, so that it takes one CLI command to create the defined as code cloud infrastructure. Project management/Tracking I am used to daily reporting and knowing that communication is the key, I constantly try to improve clients' experience. I know best methods in version control and I conform to them, doing PRs, releases, keeping multiple branches, and using stashes. ---- I have automated branching & PR requests, as well as connected bots for notifying about changes in corporate chats.The code I write goes through automatic code-styling processing that improves readability and overall quality of the provided work. I use: ESLint and Prettier for all automated code formatting needs. Respectfully, Olzhas