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I’m a dedicated QA Engineer with 5+ years of experience in manual and automated API testing. I specialize in designing and executing test cases, writing test scripts, and ensuring the integrity of backend services across various environments. My toolkit includes Postman, REST Assured, Swagger, JMeter, Selenium, Java/Python, and CI/CD tools like Jenkins. What I can help you with: • Manual API testing using Postman/Swagger • Writing automated API test scripts (REST Assured, Python requests, etc.) • Integration testing of microservices • Performance/load testing of APIs (JMeter) • Test case creation & execution • Bug tracking and reporting (JIRA, TestRail) • CI/CD test automation integration I’m passionate about clean, well-documented code and transparent communication. Whether you need to validate your REST APIs or set up a robust automation suite, I can help ensure your system is stable, secure, and production-ready. Let’s connect and build quality software together!

Your AI chatbot should answer customers and close deals at 3 a.m., not just look good in a demo. I'm an AI Chatbot Developer who builds the ones that run in production: 53 Upwork projects, 3,000+ hours, 100% Job Success, Top Rated. 🧠 AI Agent Developer · 🤖 AI Chatbot Developer · 📚 AI RAG · 💬 Telegram, Slack & WhatsApp bots · 🚀 18+ yrs coding 👋 About Me I'm Alex, a senior AI Chatbot Developer and AI Agent Developer from Kyiv, Ukraine, with 18+ years of coding and bots since 2013, from simple Slack bots to AI RAG and LLM-powered AI agents. Before going full-time freelance in 2018 I built banking software for Barclays and Deutsche Bank, so every project gets enterprise-grade code: secure, tested and documented. One agentic AI developer, no hand-offs: as your AI Chatbot Developer and AI Agent Developer I handle AI Chatbot Development, AI Agent Development, backend, admin dashboard and deployment myself. You get one point of contact, daily updates and a working demo every week. 🧠 What I Build • AI Agent Development of multi-agent systems on LangChain, LangGraph, CrewAI and AutoGen with tool calling, memory and human handoff, for sales, support and lead generation (30+ agents shipped as AI agent builder) • AI Chatbot Development of Python chatbots for websites, Telegram, WhatsApp, Slack and Messenger with Natural Language Processing (NLP) → 70%+ of customer queries resolved without a human • AI RAG systems that ground Generative AI answers in your docs, CRM and databases on FAISS, Pinecone and Chroma, with source citations • AI sales agents & deal closer chatbots to qualify leads, book calls and follow up 24/7 → up to 35% higher conversion • AI Agent Development & AI agent automation with AI agent n8n workflows and API integrations connecting agents to your CRM → 400+ hours/month saved on average • Full-stack ai chatbot development with React & Node.js admin dashboards, PHP and WordPress plugins, Stripe & Blockchain payments (bot development end to end) 🚀 Recent Projects • CRM & booking SaaS: as AI Agent Developer I built a multi-tenant AI agent service of 3 agents (booking, sales, analytics) with 12+ API tools for 40+ businesses → bookings 100% automated, 60% less admin time • Telegram networking startup: end-to-end AI Chatbot Development of a GPT-4 AI agent for double opt-in warm intros, shipped in 6 weeks → 1,200+ users, 300+ intros made, 85% opt-in rate • Online community: AI Chatbot Development of a Generative AI chatbot with AI RAG over 500+ documents auto-translating for 5,000+ members in 12 languages → 80% of questions answered without an admin • AI product team (long-term): as AI Agent Developer and AI agent creator I build LangChain + LangGraph agents with AI RAG on MongoDB Atlas, adding reranking, retries and automated evals → 10K+ documents searchable, answer accuracy 72% → 91%, 40% lower LLM cost • Spreadsheet chatbot SaaS: as lead AI Chatbot Developer I built a Telegram + WhatsApp chatbot that answers natural-language questions via AI RAG over spreadsheet data (Data Analysis without formulas) → 10K+ users, 1M+ queries answered, 5+ years in production 🏗 Industries: 7+ sectors across 30+ countries • SaaS & CRM: AI agent development for bookings, sales chats and lead qualification, support based on AI RAG • Healthcare & telemedicine: patient FAQ RAG chatbot, medical documentation AI agent with AI RAG • E-commerce & retail: as AI Chatbot Developer I built order-taking chatbots and chatbot marketing on Telegram, Messenger and Shopify • Insurance & fintech: chatbot for quotes and claims, payment bots with Stripe, AI agent crypto for Blockchain • Recruitment & HR: AI chatbot for hiring sites, AI Agent Development for Telegram warm intros • Communities & social apps: Telegram bots for 5,000+ members Open to any domain where AI chatbot development or AI agent development can save time or drive business development 🛠 AI Chatbot Development & AI Agent Developer Stack • AI Agent Development: LangChain, LangGraph, CrewAI, AutoGen, OpenAI • LLM: Open AI chatbot, Claude, Gemini, GPT-3+ integrations • Python: Flask, FastAPI, PyTorch & TensorFlow • AI RAG: FAISS, Chroma, Pinecone, Weaviate, MySQL, PostgreSQL, MongoDB • Messengers: Website chat, Telegram bot, WhatsApp chatbot, Facebook chatbot, Instagram chatbot, Slack bot & Discord bot • Platforms: DialogFlow, ManyChat, Botpress, Voiceflow chatbot, Tidio, Conversiobot, Rasa & GHL chatbot • Web developer: JavaScript, Node.js, React, PHP • AI/ML: Artificial Intelligence, Machine Learning, Deep Learning, Neural Network, Data Science 🤝 How We Start Send me your idea: 2–3 lines about your business and what the AI agent should do. Within 2 hours you get a clear plan with the stack, 3 quick wins and a realistic launch date, free of charge. Prefer to talk first? Book a 30-minute consultation. 📩 Looking for an AI Chatbot Developer or AI Agent Developer who ships to production, not demos? Let's build it.

You get the developer who actually writes the code - not an account manager who forwards your emails, and no handoff to a junior once the contract is signed. Most of my clients come to me with an ASP.NET or Umbraco site someone else built and then disappeared from: no documentation, an old framework version, a list of changes nobody will quote on. I work with what's already there, and I'll tell you honestly what your site needs and what it doesn't. 20+ years in C#. On Upwork alone: 160+ contracts and 12,000+ hours, all visible below. Sites I've worked on include Twinings (UK), The Rocks and Darling Harbour (Sydney). The feedback tags clients choose most often for my work are Committed to Quality, Collaborative and Clear Communicator. The numbers are in my work history below. I'm based in Ukraine. I have stable power and internet with backup for both, and I'm exempt from military service, so there's no risk of me being called up mid-project. I've been working without interruption since 2022, and Reliable is one of the tags clients pick most often in my work history. My timezone is UTC+2, which overlaps fully with UK and EU hours and covers the morning, lunchtime and early afternoon on the US East Coast. What I do - New pages, sections and features on your existing site - Fix what's broken - forms, errors, search, integrations - Take over inherited or abandoned projects: undocumented code, outdated packages, failed upgrades - .NET and Umbraco version upgrades, security updates - An admin panel your team can use without calling a developer - Find and fix what's actually making your pages slow Umbraco CMS - Umbraco 7-18, including v13 and v17 LTS - Upgrades and migrations: legacy Umbraco versions, uSync, content migration - WordPress to Umbraco - Backoffice extensions: Custom Property Editors, Dashboards, Trees, Web Components - Umbraco Cloud, Azure App Service ASP.NET without a CMS - ASP.NET Core, MVC, Razor Pages, Web API - custom sites, admin panels, customer portals - .NET Framework to .NET 8+ migrations: MVC 5, Web Forms, legacy Web API - SQL Server, PostgreSQL, Oracle, Entity Framework, Dapper - REST APIs and third-party integrations, including Amadeus - Git, CI/CD, code review - AI-assisted development (Claude Code, Codex, Google Cloud, Copilot) eCommerce & payments - Umbraco Commerce (formerly Vendr), uCommerce, Merchello · Stripe, PayPal, Worldpay, SagePay Send me the site URL and a short description of the problem. I'll identify what you're running on, assess the likely cause, and give you a realistic estimate before any development starts.

✅ 100% Client Recommendation ✅ Top Embedded and Firmware developer ✅ Top Hardware designer ✅ Top Software design ✅ Top Mechanical design and industrial design ✅ Top Enclosure design Services: 1) Hardware/Electronics design (Power, Analog, Digital/High-speed and RF electronics design) 2) Precertification testing (EMI, ESD, EMC, FCC, CE, UL) 3) Firmware design С/C++ (Bare metal MCU/MPU, FreeRTOS, Zephyr RTOS, Embedded Linux, Wireless protocols, Security, Interfaces, etc) 4) Industrial and Mechanical design (Enclosure design, 3D printing, IP standards, Prepare all for injection molding, etc) 5) UX/UI design (Embedded devices with displays, Mobile and Desktop applications) 6) Software design (Android, IOS, Linux kernel and user space development) 7) Embedded Quality Assurance(QA) and testing 8) Manual verification/testing PCB/FPC, functional and unit testing of the Firmware/Software, stress testing, temperature range testing Service->Hardware design service: - Power electronics design: (PFC, Solar charging controller, chargers, high voltage control, Motor controllers DC/AC/BLDC ) - Analog electronics design: High-accuracy analog measurements, Noise filtration, Digital to analog conversion, Amplifying signal - Digital and high-speed electronics design: - Memories DDRx/LPDDRx, SDRAM, Camera and display interfaces (MIPI-DSI, MIPI-CSI, DisplayPort, etc), Data communication interfaces (QSpi, SPI, UART, I2C, FMC, I2S, USB 2/3.x, etc), ( - RF Designs: ( 50-60 GHz (Radars), 1-6 GHz (UWB, Wifi, BLE, ZigBee, GPS, NB-IoT, LTE-M/LTE, Z-Wave, etc), 13,6 MHz, 128 kHz (NFC, RFID, etc), 433 MHz (Custom protocols) Service->Industrial and Mechanical design - Industrial design of the sketch - it includes a few sketch designs, depending on the physical sizes of the device, specific of industry and user experience - Mechnical CAD design with deep PCB integration - it includes full mechanical draw based on the industrial design with detailed sizes, materials and manufacturing specific. - Thermal calculation and simulation - it includes simulation of the heating device inside enclosure, with theoretical cooling calculation - 3D printing and verification - we use 3D printer hp jet fusion 5210, with a very nice quality of printing, that helps us to make a good verification of parts with PCBs - Injection molding - the last step, which includes manufacturing optimization and making pres forms, preparing documentation for the manufacturing Service->Firmware design С/C++: - Languages: C/C++, Assembler - Diagrams: Block, UML, Workflow, APIs - Interfaces: I2S, SAI, MIPI-DSI, MIPI-CSI, USB 2/3.x, LTDC, DDR3/DDR4/LPDDR4, I2C, SPI/QSPI, UART, CAN, Ethernet - Wireless: NB-IoT, LTE M, GPRS, GPS, LTE, UWB, WiFi, BLE, ZigBee, Z-Wave, LoRa, Thread, 6LoWPAN, Sub 1GHz, NFC (13,6 MHz), RFID 433 MHZ and 128 kHz - Protocols : MQTT, HTTP, FTP, Modbus TCP/RTU, SNMP, TCP/IP, UDP/IP, DLMS, custom protocols - Security: AES, SSL/TLS, custom algorithms - Libs and frameworks: TouchGFX (GUI lib for MCU), emWin (GUI lib for MCU), LVGL (GUI lib for MCU), WolfSSL (SSL/TLS), Mbed TLS(SSL/TLS), osxMotionFX (Sensors fusion algorithm based on the Kalman theory), FatFS, lwIP (TCP/IP stack), WICED (Wifi stack), aws/amazon-freertos, Paho MQTT, TensorFlow - Embedded OS: FreeRTOS, TI-RTOS, ZephyrOs, Embedded Linux, Yocto, ROS - MCUs: NXP (i.MX RT1064, LPC1100, LPC4000), Nordic (NRF52xx/NRF53xx/NRF91xx), TI (CC3220/CC26xx/CC1100/CC3200, MSP430), Espressif (esp32, esp8266), ST(STM32H7/F7/F4/L4/F0/L0/WB/WL/G0 and STM8), Atmel/Microchip(SAM D20/D21/L21/R21/V70/V71, SAMA5/SAM4/SAMD4), Silicon Labs(EFR32, ZGM130S), Cypress (PSoC 3/PSoC 4), Kinetis (Family MK81FN256VDC15), Holtek (HT68xx) - MPUs: Analog Devices (ADSP-2156x SHARC), Qualcomm (Snapdragon 625/425/610/845), Allwinner (A64, A33, H3, H6 series), NXP (I.MX6/I.MX7/I.M8) , ST(STM32MP1) - SOMs: NVIDIA Jetson nano, NVIDIA Jetson Orin Nano, NVIDIA Jetson AGX Orin, Toradex (Colibri iMX6, IMX7, IMX8), Raspberry pi (CM3, CM4 modules), Inforce (Qualcomm Snapdragon 410, 820, 845 SOM), 8devices (Mango on Qualcomm IPQ6000/IPQ6010 Soc), Sensiedge(SensiBle 1 and 2, SensiLora) Service->Software: - Languages: Java, Kotlin, C#, C/C++, Python, Java Script - Diagrams: Block, UML, Workflow, APIs - Interfaces: USB, Ethernet - Protocols : MQTT, HTTP, FTP, Modbus TCP/RTU, SNMP, TCP/IP, UDP/IP, DLMS, custom protocols - Wireless: BLE, WiFi, UWB - Security: AES, SSL/TLS - Libs and frameworks: GStreamer, Paho MQTT, WolfSSL (SSL/TLS), Mbed TLS(SSL/TLS), QT framework, Xamarin Forms and Maui, ASP .NET Core and web development, React (web UI development), SQLite DB, FireBase DB, Mong DB, InfuxDB DB, Room, TensorFlow, Node.js - OS: Android, IOS, Linux, Windows