I am a Senior Full-Stack Developer with 12+ years of experience building production-grade SaaS platforms, AI-powered applications, and high-traffic web systems. I work across the full stack, delivering modern frontend interfaces, reliable backend services, and intelligent features powered by LLMs. I focus on clean architecture, maintainable code, and systems that perform well under real-world conditions. 𝐂𝐨𝐫𝐞 𝐄𝐱𝐩𝐞𝐫𝐭𝐢𝐬𝐞: 𝐅𝐮𝐥𝐥-𝐒𝐭𝐚𝐜𝐤 𝐃𝐞𝐯𝐞𝐥𝐨𝐩𝐦𝐞𝐧𝐭: SaaS Development, Web Application Development, System Design, Distributed Systems, Microservices, Monolith Architecture, Clean Architecture. 𝐅𝐫𝐨𝐧𝐭𝐞𝐧𝐝: React, Next.js, Vue.js, Angular, TypeScript, JavaScript, HTML5, CSS3, Tailwind CSS, Redux, Zustand, SSR, CSR. 𝐁𝐚𝐜𝐤𝐞𝐧𝐝: Node.js, NestJS, Express.js, Python, Django, Flask, FastAPI, RESTful Services, Event-Driven Architecture. 𝐀𝐈 / 𝐌𝐋: Deep Learning, LLM, RAG, Chatbot Development, Conversational AI, Agentic AI, Prompt Engineering, NLP, OpenAI API, Gemini API, Claude, Hugging Face, LangChain, LangGraph. 𝐀𝐏𝐈𝐬 & 𝐈𝐧𝐭𝐞𝐠𝐫𝐚𝐭𝐢𝐨𝐧𝐬: API Development, REST APIs, GraphQL, WebSockets, OAuth 2.0, JWT, Third-Party Integrations, Webhooks, Payment Integrations (Stripe), Messaging APIs (Twilio). 𝐂𝐥𝐨𝐮𝐝 & 𝐃𝐞𝐯𝐎𝐩𝐬: AWS, Azure, GCP, Docker, Kubernetes, CI/CD, DevOps, Terraform, Infrastructure as Code (IaC), Serverless, Lambda, ECS, Cloud Deployment. 𝐃𝐚𝐭𝐚𝐛𝐚𝐬𝐞𝐬 & 𝐃𝐚𝐭𝐚: PostgreSQL, MySQL, MongoDB, Redis, DynamoDB, SQL, NoSQL, Data Modeling, Data Pipelines, ETL, Data Engineering, Query Optimization. 𝐀𝐮𝐭𝐨𝐦𝐚𝐭𝐢𝐨𝐧 & 𝐏𝐞𝐫𝐟𝐨𝐫𝐦𝐚𝐧𝐜𝐞: Automation, Workflow Automation, Background Jobs, Queue Systems (BullMQ, Celery), Performance Optimization, Scalability, Monitoring, Logging. 𝐈 𝐂𝐚𝐧 𝐇𝐞𝐥𝐩 𝐖𝐢𝐭𝐡: SaaS platforms and full-stack web applications AI-powered tools, chatbots, and automation systems API-first architectures and third-party integrations Data-driven dashboards and real-time systems Cloud-based and high-availability applications 𝐖𝐡𝐲 𝐇𝐢𝐫𝐞 𝐌𝐞: Write production-ready, maintainable code Work within existing codebases and ship features quickly Communicate clearly with structured updates Take ownership from development to deployment 💬𝐅𝐫𝐞𝐞 𝟏𝟓-𝐦𝐢𝐧 𝐜𝐨𝐧𝐬𝐮𝐥𝐭𝐚𝐭𝐢𝐨𝐧 𝐭𝐨 𝐝𝐢𝐬𝐜𝐮𝐬𝐬 𝐲𝐨𝐮𝐫 𝐩𝐫𝐨𝐣𝐞𝐜𝐭. 𝐂𝐥𝐢𝐜𝐤 “𝐈𝐧𝐯𝐢𝐭𝐞 𝐭𝐨 𝐉𝐨𝐛” 𝐚𝐧𝐝 𝐥𝐞𝐭’𝐬 𝐭𝐮𝐫𝐧 𝐲𝐨𝐮𝐫 𝐯𝐢𝐬𝐢𝐨𝐧 𝐢𝐧𝐭𝐨 𝐫𝐞𝐚𝐥𝐢𝐭𝐲.

I help asset managers, macro research firms, and trading desks build the data infrastructure and systematic processes that drive better investment decisions. Strategic Services: - Market data pipeline - ingestion, normalization, and storage for tick, bar, and fundamental data - Backtesting framework - evaluating data integrity, execution assumptions, and lookahead bias - Trading system design - connecting research signals to execution across futures and other asset classes - Technology stack evaluation - helping firms avoid overengineered solutions and vendor lock-in I analyze your specific workflow, recommend the right approach, and guide you away from unnecessarily complex infrastructure. I've helped clients avoid costly architectural mistakes while building systems that actually scale with their AUM and strategy count. Technical Depth: Python, Dagster, cloud platforms (AWS/GCP), databases (PostgreSQL, DuckDB), and deep integrations with financial data providers - Databento, Polygon, Financial Modelling Prep, Interactive Brokers (TWS API) - plus 20+ other APIs including OpenAI, Claude, Deepseek, Qwen. What I Don't Do: I'm not selling you an alpha signal or a black-box algo. I assess, design, and build the infrastructure and tooling around your strategies - so your team can research, backtest, and deploy with confidence. I combine engineering depth with markets experience - understanding both what's technically possible and what actually matters for your P&L.

⚡ I build scalable, AI-driven products that go beyond features designed to grow your business. With 10+ years of experience, I help startups, agencies, and enterprises design and develop production-ready SaaS platforms, web apps, and AI-powered systems that are fast, reliable, and built for long-term success. I combine deep full-stack engineering with modern AI capabilities to create products that automate workflows, improve decision-making, and deliver real business impact. 🚀 What I Do Best ✔ End-to-end SaaS platform development ✔ Scalable web & mobile applications ✔ AI-powered systems, copilots & automation workflows ✔ Backend architecture & high-performance APIs ✔ Cloud-native infrastructure & DevOps ✔ System design for complex, business-critical applications 🧠 AI & Intelligent Systems Expertise I build real-world AI solutions not demos. ✔ LLM integrations (OpenAI, Claude, Gemini, open-source models) ✔ RAG pipelines, semantic search & vector databases ✔ AI agents, copilots & conversational systems ✔ Workflow automation & decision engines ✔ Prompt engineering & structured output design ✔ Secure, production-grade AI with monitoring and reliability 💻 Technology Stack Backend: Node.js, NestJS, Python, Django, FastAPI, PHP, Laravel Frontend: React, Next.js, Vue, Angular, TypeScript Mobile: Flutter, React Native, Swift, Kotlin Cloud & DevOps: AWS, Firebase, Docker, Kubernetes, CI/CD Databases: MongoDB, PostgreSQL, MySQL 🏗 Architecture-First Approach I don’t just write code, I design systems that scale. ✔ Clean, maintainable, production-grade code ✔ Secure and high-performance backend systems ✔ Scalable cloud architecture ✔ Reliable integrations and automation pipelines 🌍 Industry Experience FinTech • Healthcare • eCommerce • Real Estate • Logistics • Education • IoT • SaaS • AI platforms 📊 Proven Track Record ✔ 24,000+ hours delivering production software ✔ Long-term client relationships & repeat work ✔ Trusted for complex, high-impact applications ✔ Strong focus on performance, scalability, and reliability 🤝 What You Can Expect ✔ Clear communication and ownership ✔ Fast, structured, and transparent delivery ✔ Business-focused decision making ✔ A long-term technology partner not just a developer 🚀 Let’s Build Something That Scales If you’re looking for someone who can combine full stack engineering with real AI implementation, I can help you turn your idea into a powerful, future-ready product. 📩 Send me a message or invite me to your job I’ll respond quickly.

I am a Fullstack Web Developer with 5 years of hands-on experience in software development, holding a Bachelor's Degree in Information Technologies from the National Technical University of Ukraine 'Kyiv Polytechnic Institute'. My primary expertise lies in building robust, scalable web applications using C#, React.js, and Next.js. I have deep knowledge of backend development with C#, leveraging ASP.NET Core, Entity Framework Core, and LINQ to create high-performance APIs and business logic layers. I actively use C# for task parallelization, memory management, and working with system-level utilities. On the frontend, I specialize in building modern, responsive UIs using React.js and Next.js. I’ve implemented several production-grade SPAs and SSR applications using React.js, and structured scalable frontend architectures using Next.js. My daily stack includes component-based development, state management, and optimization techniques in React.js/Next.js environments. I also work with: Task parallelization and scheduling in C#; Virtual machine management via SSH; Writing and executing SH, SQLPLUS, and RMAN scripts; Developing internal APIs in C# to support automation and scripting; Memory leak detection using diagnostic tools; Azure (Functions, CosmosDB, AD B2C); AWS (SES, SQS); SQL Server, PostgreSQL. Whether it's creating RESTful APIs with C#, building interactive frontends in React.js, or deploying fullstack apps using Next.js, I deliver clean, efficient, and maintainable code with a focus on performance and scalability.

An innovative professional with more than 20 years of experience in developing various types of applications. A team player, dedicated to driving continuous improvement with cutting-edge technologies and out-of-the-box thinking. Having a strong work ethic, logical, datadriven, a commitment to excellence, a deep understanding of industry best practices, and passion to learn new technology. Keep things simple, accurate, reliable, and fast.

𝙄 𝙗𝙪𝙞𝙡𝙙 𝘿𝙖𝙩𝙖 𝙀𝙣𝙜𝙞𝙣𝙚𝙚𝙧𝙞𝙣𝙜 𝙨𝙮𝙨𝙩𝙚𝙢𝙨 𝙛𝙧𝙤𝙢 𝙩𝙝𝙚 𝙜𝙧𝙤𝙪𝙣𝙙 𝙪𝙥, 𝙀𝙏𝙇 𝙥𝙞𝙥𝙚𝙡𝙞𝙣𝙚𝙨, 𝘿𝙖𝙩𝙖 𝙒𝙖𝙧𝙚𝙝𝙤𝙪𝙨𝙚𝙨, 𝙞𝙣𝙩𝙚𝙜𝙧𝙖𝙩𝙞𝙤𝙣𝙨, 𝙖𝙣𝙙 𝘽𝙪𝙨𝙞𝙣𝙚𝙨𝙨 𝙄𝙣𝙩𝙚𝙡𝙡𝙞𝙜𝙚𝙣𝙘𝙚 𝙙𝙖𝙨𝙝𝙗𝙤𝙖𝙧𝙙𝙨. 𝙈𝙮 𝙜𝙤𝙖𝙡 𝙞𝙨 𝙨𝙞𝙢𝙥𝙡𝙚: 𝙜𝙞𝙫𝙚 𝙮𝙤𝙪𝙧 𝙩𝙚𝙖𝙢 𝙧𝙚𝙡𝙞𝙖𝙗𝙡𝙚 𝙙𝙖𝙩𝙖, 𝙖𝙪𝙩𝙤𝙢𝙖𝙩𝙚𝙙 𝙧𝙚𝙥𝙤𝙧𝙩𝙞𝙣𝙜, 𝙖𝙣𝙙 𝙙𝙖𝙨𝙝𝙗𝙤𝙖𝙧𝙙𝙨 𝙩𝙝𝙖𝙩 𝙢𝙖𝙠𝙚 𝙞𝙩 𝙚𝙖𝙨𝙞𝙚𝙧 𝙩𝙤 𝙨𝙚𝙚 𝙬𝙝𝙖𝙩 𝙞𝙨 𝙝𝙖𝙥𝙥𝙚𝙣𝙞𝙣𝙜 𝙖𝙣𝙙 𝙢𝙖𝙠𝙚 𝙗𝙚𝙩𝙩𝙚𝙧 𝙙𝙚𝙘𝙞𝙨𝙞𝙤𝙣𝙨. 𝙃𝙚𝙧𝙚’𝙨 𝙬𝙝𝙖𝙩 𝙄 𝙘𝙖𝙣 𝙝𝙚𝙡𝙥 𝙬𝙞𝙩𝙝: 𝟭. 𝗗𝗮𝘁𝗮 𝗘𝗻𝗴𝗶𝗻𝗲𝗲𝗿𝗶𝗻𝗴 & 𝗗𝗮𝘁𝗮 𝗪𝗮𝗿𝗲𝗵𝗼𝘂𝘀𝗶𝗻𝗴 🔹 Data Warehousing from scratch 🔹 SQL, Python & Data Modeling 🔹 Snowflake, BigQuery, Databricks & PostgreSQL 🔹 Database Design & cloud migrations 𝟮. 𝗘𝗧𝗟 & 𝗗𝗮𝘁𝗮 𝗜𝗻𝘁𝗲𝗴𝗿𝗮𝘁𝗶𝗼𝗻 🔹 ETL / ELT pipeline development 🔹 APIs, CRMs, ecommerce & advertising data 🔹 Fivetran, Airbyte & dbt 🔹 Fixing broken or unreliable ETL pipelines 𝟯. 𝗕𝘂𝘀𝗶𝗻𝗲𝘀𝘀 𝗜𝗻𝘁𝗲𝗹𝗹𝗶𝗴𝗲𝗻𝗰𝗲 & 𝗗𝗮𝘀𝗵𝗯𝗼𝗮𝗿𝗱𝘀 🔹 Power BI & Tableau dashboards 🔹 Business Intelligence reporting 🔹 Data Visualization & KPI dashboards 🔹 Marketing, sales, finance & operations reporting 𝙏𝙤𝙤𝙡𝙨: Power BI | Tableau | SQL | Python | Snowflake | BigQuery | dbt | PostgreSQL | Fivetran | Airbyte | Looker | AWS | Azure | GCP 𝙒𝙚 𝙖𝙧𝙚 𝙖 𝙥𝙚𝙧𝙛𝙚𝙘𝙩 𝙢𝙖𝙩𝙘𝙝 𝙞𝙛 𝙮𝙤𝙪 𝙣𝙚𝙚𝙙: 𝟭. Data Engineer 𝟮. Data Engineering 𝟯. ETL Developer 𝟰. Data Warehouse Developer 𝟱. Business Intelligence Developer 𝟲. Power BI Developer 𝟳. Analytics Engineer 𝟴. Data Integration Specialist 𝟵. SQL Developer 𝟭𝟬. Tableau Developer 𝙄𝙛 𝙮𝙤𝙪 𝙣𝙚𝙚𝙙 𝙖 𝙨𝙚𝙧𝙞𝙪𝙨 𝙙𝙚𝙫𝙚𝙡𝙤𝙥𝙚𝙧 𝙩𝙤 𝙗𝙪𝙞𝙡𝙙 𝙮𝙤𝙪𝙧 𝙙𝙖𝙩𝙖 𝙨𝙮𝙨𝙩𝙚𝙢 𝙛𝙧𝙤𝙢 𝙨𝙘𝙧𝙖𝙩𝙘𝙝 𝙤𝙧 𝙛𝙞𝙭 𝙬𝙝𝙖𝙩 𝙮𝙤𝙪 𝙖𝙡𝙧𝙚𝙖𝙙𝙮 𝙝𝙖𝙫𝙚, 𝙨𝙚𝙣𝙙 𝙢𝙚 𝙖 𝙢𝙚𝙨𝙨𝙖𝙜𝙚.

MBA graduated and Certified Data Analyst, I have 10+ years in customer success, and business units management. I am also an Expert in SQL (certified) and Zoho Analytics (Partner). I can also work on other BI platforms (Power BI, Tableau, Data Studio). I can help with data processing/cleaning/preparation as well as Business Intelligence, automation of day-to-day business processes, and Zoho One implementation. Dynamic, resourceful, skilled, and versatile, I'll be of great help with your projects. Some of the projects I've done: - Zoho One set up and its applications (Zoho Analytics, Recruit, Desk, and more). - CRM and ERP automation, - Marketing automation and analysis - Data Visualization with tools such as Zoho Analytics, Domo, Power BI, Tableau, and Google Data Studio. - API integration to these BI platforms and data architecture - any Excel / Google Sheets projects Looking forward to working with you!

Over 7 years of working experience in automating data pipelines. Worked with AWS,Postgres,Redshift Bigquery,MLops ,python and automation platforms. AWS data analytics and machine learning certified.

I am having experience of 7+ years in the development of .Net large-scale applications In .NET Core. I am also an expert in Blazor & MAUI. Already worked with .NET 8 and 9 and have good understanding in .NET 10. I have worked with Fulltime NET Developer for both MVC and NET Core. Here are some of my skills and qualities: Posse’s strong knowledge of Technologies like .NET CORE, C#, ReactJS, NodeJS, Blazor, ADO.Net, MVC, Linq to SQL, Entity Data Model, .NET 8, Python, flask and Django Databases: MSSQL, SQL Server Azure: Azure AD, Azure DevOps, Azure Table, IaaS, PaaS, Containers, Storage, Azure Monitoring, Security, Azure SQL, AppService, Logic Apps, Functions, Azure API and other Serverless services Management: Azure Service bus, Azure Event Hub, Azure Batch, Azure App Services, Docker, Kubernetes Messaging Broker: RabbitMQ Caching: Redis Containerization: Azure Functions. Authentication: OAuth, Microsoft Authentication Front-end tools: HTML, Jquery, JavaScript, Bootstrap, XML,chronologies, and AJAX methodologies. Monitoring: Application insights. Project management tools: Jira, Basecamp, Trello, Asana Scripting Languages: JavaScript Hosting: AWS Azure Other Tools: GIT, TFS, Bitbucket, Devops Primary Skills (Core Stack): - Full Stack Developer - .NET Developer - ASP.NET Core Developer - C# Backend Developer - React.js Developer - Angular Developer - Blazor Developer - MAUI App Developer - .NET MAUI Developer - Web API Developer - Entity Framework Core - Razor Pages - SignalR Developer Frontend Technologies: - JavaScript Developer - TypeScript Developer - HTML5 / CSS3 / SCSS - Responsive Web Design - Tailwind CSS - Bootstrap - React Hooks - Angular Material - RxJS - Material UI (MUI) Backend / Server-Side - ASP.NET Core Web API - RESTful API Development - Microservices Architecture - Clean Architecture - Dependency Injection - Middleware in .NET - LINQ / EF Core - SQL Server / PostgreSQL / MySQL - IdentityServer / JWT Authentication Version Control & Tools: - Git / GitHub / GitLab / Bitbucket - Azure DevOps Pipelines - Jira / Trello / ClickUp - Visual Studio 2022 - Postman / Swagger - Figma to React/Angular Testing & Quality: - Unit Testing in .NET (xUnit, MSTest) - Jest for React - Cypress / Selenium - Playwright - Code Review & Refactoring Cloud & DevOps: - Azure Developer - AWS Developer - Azure App Services - Azure Functions - AWS Lambda - CI/CD (GitHub Actions, Azure DevOps) - Docker - Kubernetes - Softr - Cloudflare I am also Responsible for implementing security using OAuth within REST Api (WebAPI 2).

As an Upwork Expert-Vetted and Top-Rated Plus professional, I’m in the top 1% of experts in this field. When it comes to data, I love to find creative and visual ways to tell a story. I've learned a lot over the last 10 years and most importantly that there is always more to discover. I specialize in Tableau, Microsoft Power BI and Apache Superset to visualize your data. I use Figma to create compelling wireframes and designs to bring the UI and UX to life. And I work with my clients to understand who they are and what they do... ✨Data Visualization Strategy // consulting to get you started on your data viz journey ✨Dashboards & Reports // let's get building in Tableau, Power BI, or Apache Superset ✨UI/UX Design // let's bring your data story to life in Figma and enhance existing content ✨Embeded Analytics // simplify your tech stack by embedding dashboards and reports ✨Custom Web Portals // build a professional custom web portal for your org or clients to access content Let's get started on your story... James Jeffrey Data Visualization Lead @ Radar BI