More than 21 years of experience on Java/JEE, PHP, C, C++, Perl, Shell Script, JavaScript MySql and Oracle technologies. An experienced Software Engineer/Architect with having strong R&D[Research & Development] background. Enjoy working on research based development, creating API/SDK, application framework and performance engineering, testing, code profiling, code optimizing, query optimizing, team and project managing. Experienced in designing Cloud computing/service, Semantic web, Sensor network, Ontology, SSO/Identity management, Asynchronous architecture, Mobile based App[Android] Data collector[xForm], Asterisk[AMI/AGI] based interactive IVR application, mHealth, e-Education, disaster and early warning system, Courier & Freight Software, Warehouse & Retail Supply Chain Software, Corporate Mailroom Software, Travel Software, Billing software and Web Bot. Wide and deep knowledge in Java/JEE Technology & OOP Architecture, REST/RESTful architecture, design patterns. Experience in Business intelligence and Reporting Tool. Workflow and BPMS. RDBMS. Solid background in Object-Oriented analysis and design UML, Design Patterns, Architecture Patterns and Software development methodology (Agile/SCRUM/TDD). Technical experienced on Java/JEE, EJB3.0, Spring, Hibernate, JPA, JSF, RichFaces , PrimeFaces Wicket, Struts, DWR, GWT, AngularJS, PhantomJS, Android, HTML, CSS, JS, jQuery, JAX-WS, JAX-RS, SOAP, Maven, Gradle, Jenkins , CloudBees, Google App Engine, Amazon AWS, jBPM , ESB, Node.js ,MySQL, ORACLE, PostgreSQL, SQL Server, MongoDB etc My preference to work on long term project. It could be hourly or fixed price job but hourly job is my first preference. I would like to maintain trustworthily long term relationship through good work. If anyone is there on the same page and match my criteria please poke me for further... More details about technical skills --------------------------------------------------------------------- Programming Languages: J2EE/J2SE/J2ME, Scala, JRuby, C/C++, Assembly, HTML/HTML5 /DHTML/ XHTML, JavaScript, Ajax, XML/XSL, PHP, Android. Frameworks & Toolkits: Spring, EJB3.0, JPA, Hibernate, S2Dao, S2Hibernate, Seasar, JSF, RichFaces, PrimeFaces, Wicket, Struts, DWR, SWT, GWT, Facelets, MIDP 2.0, JavaRosa, Smarty, ADODB, Yii, CodeIgniter, Laravel, Node.js, Dojo, jQuery, AngularJS, PhantomJS. GUI's: SWT, Eclipse RCP & RAP, JFace, Swing/JFC, AWT, JavaDesktop, Java2D, JGoodies. Databases: Oracle, MYSQL, PostgreSQL, MongoDB, SQL Server, JavaDB, FireBird, HSQL Template Languages: Apache Velocity, Handlebars, Nunjucks Build and Logging Tools : Apache Ant, Maven, Gradle , Jenkins , Log4j, gulp, Liquibase Application Servers: Glassfish, Tomcat, WildFly, WebLogic, Jetty Testing Tools: Selenium, JUnit, EasyMock, Mockito, Mercury LoadRunner, JMeter, BlazeMeter. XML's: XML (Dom, Xerces), XPath, Schema, XSD, RDF, Xform (openrosa & javarosa). Workflow (BPMS) & ETL: jBPM, Kettle, Talend. Business Intelligence & Reporting Tool: Eclipse BIRT, Pentaho, JasperRepors. IDE's: Eclipse, NetBeans, IntelliJ, MyEclipse Project Management Tools: SFEE (Source Forge Enterprise Edition), Subversion, Mylyn, Version One, Target process, JIRA, WorkFront, Asana, Redmine, CVS, SVN, GIT, Marcural Methodologies: RUP, Agile, XP, Scrum Operating Systems: Sun-Solaris-x86(10), Linux Family (Redhat/obuntu/Suse), Windows Family (NT/XP/98/2000/2003, vista).

👍🏻 "Working with Artur was fantastic. He took full ownership of our project and delivered vital improvements for our open source libraries. We got over 1,000 new signups after rolling out the new features." - Andrew H., CTO of a company servicing SalesForce, Heroku, twitch, BlueApron, Twilio and Kayak 👍🏻 "You're worth your weight in gold! Thanks to the development improvements you introduced our team is two times more productive." - Peter C., CTO of a San Francisco-based website averaging 1M+ visitors a day 😖 Are you not sure how to build the technology to deliver your service to thousands of users? 😬 Are your customers leaving you because the bugs on your website are just piling up? 😡 Is it too hard to find high-quality developers who don’t leave your projects in a mess? Welcome! I'm a tech entrepreneur and a master developer. I build internet businesses from scratch and help companies create profitable software every day. I’ve helped over 30+ companies from Silicon Valley, London, New York City and other tech-bubble centers launch Software as a Service. Over 8 years in the web development industry has taught me the secret ins-and-outs of the technology world. 💰 How can I help you? ✅ create your Software as a Service platform ✅ build a payment ready website that will bring you recurring revenue every month ✅ integrate you with Stripe, MailChimp, Facebook, Twitter, LinkedIn, Pinterest and more ✅ cut your operations costs by setting up automation software, CRM and more ✅ build your Shopify store from ground up (or any other e-commerce) 🤝 What can you expect from me ➡️ I deliver what you expect and I deliver on time ➡️ a long-term business relationship (I do not accept one-off projects!) ➡️ no theoretical nonsense; I focus on what makes cash for your business 💰🤝💻 If you send me a message we will set up a call. You’ll tell me what you’re trying to do, what your current obstacles are and I will tell you how to build it. Let’s get in touch!

I build production-grade AI voice systems and scalable backend platforms. I’m a Senior Full Stack Developer and AI Automation Specialist with hands-on experience designing and running real-world AI infrastructure, including my own platform FreeAIVoice, where I developed and deployed: GPU-based Text-to-Speech (TTS) systems Speech-to-Text pipelines using Whisper Voice cloning and multilingual voice systems High-performance FastAPI services with queue-based processing Scalable backend architecture using .NET Core, SQL Server, MongoDB, and Redis What I Can Do For You AI Voice & Speech Systems Text-to-Speech (TTS) using Coqui XTTS, Kokoro, ElevenLabs Speech-to-Text (STT) using Whisper Voice cloning & multi-speaker systems Audio generation pipelines (high throughput, GPU optimized) Streaming or batch audio APIs Backend & API Development FastAPI (Python) high-performance APIs ASP.NET Core / MVC enterprise applications REST API design with authentication, rate limiting, usage tracking Queue-based systems (MongoDB / Redis) Multi-threaded and multi-GPU processing systems Database & Performance Optimization SQL Server (DBA-level optimization, stored procedures, indexing) MongoDB (aggregation pipelines, queue systems) Redis caching for high-speed systems Query optimization for large-scale datasets System Architecture & Scaling AI system design (end-to-end pipelines) GPU workload optimization (parallel processing) Load balancing across multiple servers Docker & Linux (Ubuntu) deployment Cloud + on-prem hybrid systems Real Experience (Not Just Theory) I don’t just experiment — I build real systems. Developed and running FreeAIVoice platform Built multi-threaded TTS system with 2000+ audio generations per minute Designed scalable queue-based architecture for AI workloads Integrated AI into production SaaS systems (telephony & automation) Why Work With Me? I understand both AI + real production systems Strong combination of .NET + Python + AI (rare skillset) Focus on performance, scalability, and reliability I think like a solution architect, not just a coder Let’s Talk If you're building: AI voice platform TTS / Speech system SaaS backend High-performance API I can help you design, build, and scale it properly. Skills Text-to-Speech (TTS) Speech-to-Text (STT) Whisper Coqui TTS FastAPI Python ASP.NET Core C# SQL Server MongoDB Redis REST API Development AI Development Machine Learning Deployment Docker Linux (Ubuntu) GPU Computing

Full-stack developer of complex business applications with a focus on data What I do best: ⚙️ Custom business automation where standard software doesn't work/is expensive. I know ways to drive your recurring costs toward zero 🧠 Product aggregation and matching 🔌 API integrations and development of APIs ⏱️ Long-term scraping projects built for maximum robustness and reliable data delivery 🗄️ High-quality scraping of bulk data (millions of products, terabytes of images) 🦾 Browser automation Projects I have completed and now maintain: 📧 A full-featured BYOK email automation platform packed with everything you need to run email marketing campaigns on your own — paying only for your SMTP server. 🏢 An internal platform for an advertising company to manage the distribution of product samples to ~1M people yearly. Features include a 1.2M contacts database, a built-in email platform, invoice generation for subcontractors, reports and dashboards to measure employees’ and subcontractors’ KPIs, project management, task management, and more. 💬 A version of email marketing software for communication with customers on an Airbnb-like platform. 🏠 Data aggregation and analytics software for two Airbnb-like platforms that helps hosts make better decisions by analyzing competitors’ prices, availability, and income trends. 🗂️ Product/real estate/jobs aggregator handling inventories of up to 10 websites, 100K+ products, with a 1-hour update cycle. Includes an API and integrations for WordPress and WooCommerce. How I work: You simply describe the problem you want to solve, and I help shape the idea of a product that will solve it effectively. Then, I quickly deliver to you the minimally viable product (MVP), and we can evaluate it live and improve it to perfection. I can do it because: - I have 10 years of experience as the head of an IT department in a small company, serving as an intermediary between completely non-technical people and a team of developers. - I have even more years of experience as a programmer and already built solutions for most common business challenges. - I'm a full-stack programmer with DevOps skills. I can build any web app for business from scratch, deploy it, and debug it until it works fine. I can work without any prototypes — if you have some, they’re also welcome. - I'm an AI enthusiast, making use of AI everywhere it can help. - Proven track record: 9 years on Upwork, 100% job success. Feedback: 💭 "Petr was fantastic to work with! He was thorough, made sure to understand the project requirements well and executed flawlessly" 💭 "The job was complicated, and Petr succesfully went back and forth in the initial deliverables, until we could get the product we needed" 💭 "He battled through to the end, not giving up, remaining responsive, and delivering excellent results. We paid a 1000% bonus and he earned every dollar of it" Many can write code. Few can make a product that works for you. Click "Invite to Job" and let's get things done. ===================== Key skills: Python, Playwright, Beautiful Soup, PHP, WordPress, Woocommerce, API, BYOK, DuckDB, Clickhouse, MySQL, Excel, Google Sheets, API, AI, OpenAI, ChatGPT, RESTful API, Web Development, Front-End Development, Back-End Development, API Development, Web API, Full-Stack Development, HTML5, CSS3, JS, JavaScript, Bootstrap, jQuery, Ajax, AWS, Linux, Ubuntu, Nginx, Apache, memcached, CRM, ERP, DMS, HTML, CSS, Dashboard development, Data visualisation, Project Management Software, Customer Relationship Management Software, Distribution Management Software, Web services, Pipedrive, n8n, XML, XSL, JSON, Shell Scripts, UI, UX, Stripe, Paypal, Google Maps, Google API, Google Charts

As a Top Rated Plus Python Full stack developer, I help startups and product teams bring backend-heavy, modern web applications to life. My work spans from product ideation and architecture to automation, AI integration, and ongoing performance tuning. My stack includes Python (FastAPI, Django, Flask), React, Next.js, NestJS, PostgreSQL and AWS, enriched with scalable data pipelines, monitoring, and automation tools. With over 9+ years of experience and a 100% Job Success Score, I’ve led and delivered more than 40 web apps and five large-scale platforms with high concurrency. ✅ A tech Partner from Architecture to Deployment. Clients work with me because I don’t just code features, I architect scalable, cloud native systems that require minimal oversight. ✔️ Backend: Python, FastAPI, Django, Flask, NestJS, REST APIs, PostgreSQL, MongoDB, Redis ✔️ Frontend: Next.js, React, Tailwind CSS, SSR/CSR, reusable UI libraries ✔️ Cloud: AWS (Lambda, EC2, S3, Step Functions), Docker, GitHub Actions ✔️ Automation & AI: OpenAI API, Langchain, LLM, Make, Zapier, n8n, RAG Agents, AI Agents, Generative AI I’ve also led and mentored engineering teams up to 45 developers, helping deliver across sprints while balancing performance, timelines, and quality. 🏆 Highlighted Work & Outcomes ✔️ Frontend Engineering (React + Next.js) Built fully responsive interfaces using React and Next.js, optimizing for performance and API sync with FastAPI based backends. ✔️ Scalable API Infrastructure (Python, FastAPI) Refactored a high-load backend to handle massive traffic spikes using FastAPI, Redis caching, and PostgreSQL. Supported mission-critical uptime for end users. ✔️ Retention-Driven Feature Delivery. Built backend features that improved session time and user retention in a high-growth mobile app com, bining Redis-based response optimization with async jobs. ✔️ AI Feedback Engine with OpenAI API. Built a GPT-driven evaluation engine for a learning platform. Reduced manual grading efforts and added dynamic feedback for students. ✔️ Cloud Automation & ETL Pipelines. Designed serverless pipelines using AWS Lambda and Step Functions to transfer and transform millions of files with isolated, scalable logic. ✔️ Monitoring & SLA Tools Integrated ELK stack, Grafana, and PagerDuty into production systems to track uptime, detect anomalies, and support SLAs for enterprise clients. 🎯 Technical Stack & Core Skills ✔️ Languages & Frameworks Python, FastAPI, Django, Flask, Node.js, JavaScript ✔️ Frontend Next.js, React.js, TailwindCSS, PWA, SSR/CSR ✔️ Backend & Databases RESTful APIs, OAuth2, PostgreSQL, MongoDB, Redis Celery/RQ task queues, ETL pipelines, and background jobs ✔️ Cloud & DevOps AWS Lambda, EC2, S3, Step Functions, EventBridge, CloudWatch, Supabase Docker, GitHub Actions, CI/CD pipelines ✔️ Automation & AI OpenAI API, Langchain, GPT-4/4o, Prompt Engineering RAG pipelines, Agent flows, n8n, Zapier, Make com, Webhooks, Gen AI ✔️ Monitoring & Performance ELK, Grafana, New Relic, PagerDuty Async processing, caching, load testing, and SLA compliance 🎯 Domains I’ve Worked In ✔️ FinTech: Built backend APIs, fraud prevention, trading platforms in Python, FastAPI, Django, Celery, grafana, AWS. ✔️ EdTech: GPT integrations, adaptive learning tools using FastAPI, GPT API, Langchain, n8n ✔️ LegalTech: Scalable OCR + NLP processing using TensorFlow, Custom pipelines, Vector database storage ✔️ SaaS: Multi-tenant platforms, automation systems using React, Python, Next.js, Nest.js, AWS, FastAPI, Stripe, Oauth. 🎯What Sets Me Apart ✔️ Proven experience delivering complex platforms from scratch ✔️ 15M+ user databases, multi-cloud infrastructure, scalable patterns ✔️ Balanced blend of backend depth and frontend precision ✔️ End-to-end ownership: architecture, infra, dev, monitoring Let’s Build Something That Scales If you’re looking for a developer who can own the backend, integrate AI, and bring reliable systems to life, I’d love to collaborate. Send me an invite and let’s take your product to the next level

Highly skilled Software Engineer with a strong background in Data Engineering and Business Analysis, specializing in: - API Integration - Data Transformation - AI Integration (AI data processing and data analytics). - Regulatory Integration and XML business reporting - Backend My expertise includes: - Programming: Python, C#, C++, JS, SQL, PHP, web. - XML technologies: XSLT, XML Schema (XSD), XPath - API Integration: JSON, XML, SOAP, RESTful, GraphQL, OData, OAuth, cryptographic methods - XML Regulatory Reporting: xBRL, US IRS MeF, CRS/DAC7, e-invoices etc. - File Formats: Microsoft Office Open XML, XSL-FO (PDF), InDesign (IDML) etc. - Databases: MS SQL Server, Google BigQuery, PostgreSQL, etc. - AI APIs: OpenAI, Anthropic, Gemini - Cloud application deployment: Google Cloud, AWS and Azure - Business Knowledge: Accounting, financial reporting, invoicing, planning, and other enterprise business processes

𝐌𝐨𝐬𝐭 𝐝𝐞𝐯𝐞𝐥𝐨𝐩𝐞𝐫𝐬 𝐛𝐮𝐢𝐥𝐝 𝐟𝐫𝐨𝐦 𝐬𝐜𝐫𝐚𝐭𝐜𝐡. 𝐈 𝐡𝐞𝐥𝐩 𝐲𝐨𝐮 𝐥𝐚𝐮𝐧𝐜𝐡 𝐟𝐚𝐬𝐭𝐞𝐫 𝐚𝐧𝐝 𝐬𝐦𝐚𝐫𝐭𝐞𝐫. I specialize in building ready-to-deploy platforms like Healthcare systems, booking apps, SaaS products, and custom business solutions - saving you time, cost, and months of development. 𝐈 𝐚𝐦 𝐚 𝐒𝐞𝐧𝐢𝐨𝐫 𝐒𝐨𝐟𝐭𝐰𝐚𝐫𝐞 𝐃𝐞𝐯𝐞𝐥𝐨𝐩𝐞𝐫 𝐚𝐧𝐝 𝐂𝐨𝐧𝐬𝐮𝐥𝐭𝐚𝐧𝐭 𝐰𝐢𝐭𝐡 𝟏𝟐+ 𝐲𝐞𝐚𝐫𝐬 𝐨𝐟 𝐞𝐱𝐩𝐞𝐫𝐢𝐞𝐧𝐜𝐞 𝐝𝐞𝐥𝐢𝐯𝐞𝐫𝐢𝐧𝐠 𝐬𝐞𝐜𝐮𝐫𝐞, 𝐬𝐜𝐚𝐥𝐚𝐛𝐥𝐞, 𝐚𝐧𝐝 𝐡𝐢𝐠𝐡-𝐩𝐞𝐫𝐟𝐨𝐫𝐦𝐚𝐧𝐜𝐞 𝐬𝐨𝐥𝐮𝐭𝐢𝐨𝐧𝐬 𝐟𝐨𝐫 𝐬𝐭𝐚𝐫𝐭𝐮𝐩𝐬, 𝐒𝐌𝐄𝐬, 𝐚𝐧𝐝 𝐅𝐨𝐫𝐭𝐮𝐧𝐞 𝟓𝟎𝟎 𝐜𝐨𝐦𝐩𝐚𝐧𝐢𝐞𝐬. 👨‍💻 I specialize in building scalable, secure, and cloud-based backend platforms using C# ASP.NET Core, .NET 6/7/8, Web API, Microsoft Azure, AWS and the Microsoft .NET ecosystem, working across the full SDLC from system analysis and architecture to development, deployment, and long-term support. Main Focus: ✔ C#, .NET Framework, ASP.NET, ASP.NET MVC, ASP.NET Core ✔ WPF & Windows-based application development ✔ Blazor (Server & WebAssembly), Web API, REST & SOAP ✔ Entity Framework / EF Core, Dapper, LINQ, ADO.NET ✔ Angular (AngularJS-Angular 15), ReactJS, Next.js, JavaScript, jQuery ✔ SQL Server, MySQL ✔ CMS & E-Commerce: Umbraco, NopCommerce, Sitecore ✔ Cloud & DevOps: Azure, Docker, Kubernetes, CI/CD, DevOps ✔ Web & UI Technologies: Web Services, SOAP, XML, XSL, HTML, CSS, AJAX, DOM ✔ Best Practices & Methodologies: SOLID, DRY, Design Patterns, Agile/Scrum ✔ UI/UX & Design Tools: Figma, Illustrator, Dreamweaver, Photoshop ✔AI Integration: Automation, chatbots, LLM & NLP-based intelligent application features (OpenAI, Azure AI). 𝐁𝐞𝐲𝐨𝐧𝐝 𝐛𝐚𝐜𝐤𝐞𝐧𝐝 𝐝𝐞𝐯𝐞𝐥𝐨𝐩𝐦𝐞𝐧𝐭, 𝐈 𝐢𝐧𝐭𝐞𝐠𝐫𝐚𝐭𝐞 𝐎𝐩𝐞𝐧𝐀𝐈 / 𝐂𝐡𝐚𝐭𝐆𝐏𝐓 𝐀𝐏𝐈𝐬 𝐭𝐨 𝐛𝐮𝐢𝐥𝐝 𝐀𝐈-𝐩𝐨𝐰𝐞𝐫𝐞𝐝 𝐚𝐩𝐩𝐥𝐢𝐜𝐚𝐭𝐢𝐨𝐧𝐬, 𝐚𝐮𝐭𝐨𝐦𝐚𝐭𝐢𝐨𝐧 𝐰𝐨𝐫𝐤𝐟𝐥𝐨𝐰𝐬, 𝐚𝐧𝐝 𝐢𝐧𝐭𝐞𝐥𝐥𝐢𝐠𝐞𝐧𝐭 𝐟𝐞𝐚𝐭𝐮𝐫𝐞𝐬 𝐢𝐧𝐭𝐨 𝐦𝐨𝐝𝐞𝐫𝐧 𝐬𝐲𝐬𝐭𝐞𝐦𝐬. 𝐖𝐡𝐚𝐭 𝐬𝐞𝐭𝐬 𝐦𝐞 𝐚𝐩𝐚𝐫𝐭: ✔ Enterprise-grade backend architecture ✔ Scalable cloud solutions (Azure & AWS) ✔ Secure API development & system integration ✔ Clean, maintainable, production-ready code ✔ Strong communication & structured delivery I don’t just develop APIs - I architect scalable platforms that drive real business growth. Let’s connect to discuss your requirements and design a robust backend solution tailored to your needs.

I'm senior AI Engineer specializing in production LLM applications, AI Agents, RAG pipelines, MCP servers, workflow automation, and Full-Stack development. I build scalable AI products with Python, FastAPI, React, LangChain, OpenAI, Anthropic, and vector databases. 🟢 AVAILABLE TODAY 06.07 ⚡ Message me "ARCHITECT" - get a free 45-min technical review of your AI architecture, RAG pipeline, or mobile app stack. No pitch. Just honest engineering feedback from someone who's shipped production AI. 🔵 PROVEN RESULTS ◈ AxlCoach - AI Twin for Professional Coaches (live on App Store) AI-powered coaching platform · React Native · Python / FastAPI LLM orchestration · RAG · Voice/Video pipelines (CosyVoice, LatentSync) 70-85% routine questions automated · 2-3× higher engagement Multi-agent system: sport, strength, nutrition, recovery coaches Apple Health, Google Health, Garmin, Whoop, Oura integration ◈ Sfera24 - Multi-Vendor Marketplace (Europe) React / Next.js · TypeScript · Node.js · PostgreSQL Real-time booking · Stripe Connect · 10,000+ monthly bookings Multi-country launch · Clean scalable architecture ◈ Gettask24 - Service Marketplace Two-role system · 5,000+ users · Real-time chat Java / Spring Boot · React · PostgreSQL · Redis Full CI/CD · AWS infrastructure ◈ CryptaCount - Crypto Accounting Platform Python / FastAPI · React / Next.js · PostgreSQL 90+ blockchain networks · DeFi (staking, LPs, lending, bridges) Double-entry accounting · Audit trails · Cost basis (FIFO/LIFO/HIFO) 73 tax jurisdictions · IFRS, DAC8, MiCA, CARF compliance ◈ [NDA] - AI Logistics Dispatch Platform GPS tracking · Route optimization · Driver ETA React Native · Node.js · Google Maps API Real-time fleet management · Production-ready MVP 🟠 WHAT I BUILD → AI Agents & LLM Systems Agentic workflows · RAG pipelines · Vector search LangChain · OpenAI / Anthropic / Gemini Voice/Video generation · Real-time AI pipelines → Full-Stack & Mobile React / Next.js · TypeScript · Python / FastAPI React Native · Flutter · Node.js · Java / Spring Boot → FinTech & Blockchain 90+ blockchain integrations · DeFi · Smart contracts Tax compliance · Audit trails · Multi-jurisdiction reporting → Marketplaces & Booking Multi-vendor · Real-time scheduling · Payments Stripe Connect · Two-role systems · Admin panels → AI-Powered Automation Document processing · Lead qualification Workflow orchestration · Human-in-the-loop approval systems 🟡 TECH STACK Backend: Java / Spring Boot · Python / FastAPI · Node.js · SQLAlchemy Frontend: React / Next.js · TypeScript · Redux · Tailwind CSS Mobile: React Native · Flutter AI/LLM: LangChain · OpenAI · Anthropic · Gemini · CosyVoice · LatentSync · Real-ESRGAN · Hugging Face Databases: PostgreSQL · MySQL · Redis · pgvector Message Queues: RabbitMQ · Kafka · Celery Cloud & DevOps: AWS (EC2/ECS/EKS/S3/RDS/Lambda) · Docker · Kubernetes · Terraform · GitHub Actions · CI/CD Monitoring: Prometheus · Grafana · Sentry

I am a seasoned software developer with over 10 years of experience specializing in Backend and Full-Stack development. I pride myself on my excellent problem-solving skills and have a strong passion for writing clean and testable code. Clear communication is one of my strengths, making me a valuable team member in any software development project. Preferred Tech Stack: Backend: Java, Spring Boot, Thymeleaf, REST API, PostgreSQL, AWS, Linux, Tomcat, Nginx Frontend (Web): HTML, CSS, Sass, Javascript Frontend (Mobile): Flutter, Dart Cross-Platform: Flutter, Dart I am also proficient in the following technologies: Languages: Java, Scala, Groovy, Kotlin, Golang, JavaScript, TypeScript, Python, Dart, SQL Databases: PostgreSQL, MySQL, Oracle, Cassandra, MongoDB, SQLite, Neo4j Frameworks (Backend): Spring Boot, Spring Security, OpenAPI, Kafka, Zookeeper, Grails Frameworks (Frontend): Angular, React, Flutter, jQuery, Bootstrap Security: Spring Security, OAuth, JWT Technologies: HTML, CSS, JSON, XML, REST API API: REST API, OpenAPI, Swagger Messaging: Kafka, ActiveMQ, RabbitMQ Search: ElasticSearch, Lucene, Kibana Logging: ElasticSearch, Logstash, Kibana Cloud Providers: AWS, Google Cloud Testing: JUnit, Mockito, TestNG, Selenium, Cucumber, Katalon Studio Development Tools: Intellij IDEA, VSCode, Android Studio

Most mobile app projects don't fail at the code — they fail at the App Store review, the half-finished features, or the developer who starts strong and fades by week three. I build production-ready mobile apps — Flutter, FlutterFlow, Native Android, and iOS — that go from idea to live on the App Store and Play Store. 12+ years, 105+ apps shipped, 100% Job Success on Upwork. If you need a developer who can take full responsibility for delivering clean, scalable apps on time and communicates clearly throughout — that's what my clients keep coming back for. ⭐ What I do best: ✅ Full mobile app development — Flutter, Native Android (Java/Kotlin), iOS (Swift/UIKit) ✅ FlutterFlow apps — built end-to-end with Firebase, extended with custom Dart code when the visual builder hits a limit ✅ AI integration — ChatGPT/OpenAI, Gemini, Claude, ElevenLabs (TTS), Speech-to-Text, and integrating most modern AI APIs into mobile apps ✅ App Store & Play Store launch, including policy compliance & rejections ✅ Fixing, modernizing & stabilizing existing apps (crashes, performance, UI) ✅ Long-term product development & maintenance 🛠 Core expertise: Cross-Platform: Flutter, Dart, FlutterFlow (custom actions, custom widgets, Firebase integration), responsive UI, native platform channels Native Android: Java, Kotlin, MVVM, Clean Architecture, Jetpack, Android SDK iOS: Swift, UIKit, Core Data, Auto Layout, App Store deployment AI & Voice: OpenAI, Gemini, Claude, ElevenLabs, TTS/STT, real-time transcription Video & Media: FFmpeg, photo-to-video, custom camera (Camera2), image editing Backend & Data: REST APIs, JSON, Room, SQLite, Firebase Maps & Location: Google Maps, Mapbox, GPS, background location tracking Monetization: AdMob, Unity Ads, in-app purchases, Stripe, subscriptions Architecture: MVVM, MVP, MVC, clean & testable code 🚀 I've shipped apps across AI, FinTech, Parental Control, Streaming, E-Commerce, Education, GPS Tracking, QR/Authenticity, Social & Video platforms and Many more. How I work: Fast, clear communication (usually reply within minutes) Realistic timelines — and I hit them I'll tell you honestly if something won't work, instead of wasting your time and budget I believe in building long-term relationships with my clients. My support doesn't end with project delivery—feel free to reach out anytime, even after the contract is closed, if you need assistance, maintenance, guidance, or help resolving any issues. If you're not 100% sure what you need yet, send me a message — I'll help you scope it out. Let's build something that ships. — Ramkesh