⭐ Microsoft Certified Developer ⚡ Senior Full-Stack .NET Core Developer 10+ years | 50+ enterprise systems | API Integration & Azure Expert | C# / ASP.NET Core / SQL
Senior Full-Stack Developer with 10+ years of experience delivering 50+ enterprise-level Web Development and Web Application systems using C#, .NET Framework, ASP.NET, ASP.NET Core, ASP.NET MVC, JavaScript, React, Angular, AngularJS, TypeScript, HTML, HTML5, CSS, API, API Development, RESTful API, API Integration, Microsoft SQL Server, PostgreSQL, SQL, Microsoft Azure, Azure DevOps, CI/CD, Amazon Web Service, Node.js, PHP and Python. I build scalable Web Application platforms with clean API Integration, optimized SQL, and production deployments on Microsoft Azure using C#, .NET Core, ASP.NET Core, React, Angular and JavaScript. I also develop AI powered systems using OpenAI API, OpenAI, Claude, Claude API, LangChain, FastAPI, RAG, Artificial Intelligence, Machine Learning and Natural Language Processing. If you need a developer who can build scalable production-ready systems fast let’s talk.
I have built 100+ API Integration and API Development solutions using C#, .NET Core, .NET Framework, ASP.NET, ASP.NET Core, ASP.NET MVC and RESTful API architecture, integrating systems across Microsoft Azure, Azure DevOps, CI/CD pipelines and Amazon Web Service. I have implemented 70+ automation workflows using API Integration, Node.js, Python, FastAPI and SQL-based processing across Microsoft SQL Server and PostgreSQL environments.
I have delivered 50+ Web Application systems including SaaS platforms, internal tools, dashboards and integration-heavy solutions using C#, ASP.NET Core, .NET Core, JavaScript, React, Angular, AngularJS, TypeScript, SQL, Microsoft SQL Server, PostgreSQL and API Integration deployed on Microsoft Azure and Amazon Web Service. My focus is combining backend architecture with modern Web Development and Web Design for scalable systems.
⚡ What I Build
🔹 Web Application systems processing 100k+ API requests daily using C#, ASP.NET Core, RESTful API, API Development, Microsoft SQL Server, PostgreSQL and SQL optimization
🔹 Integration-heavy platforms using C#, .NET Framework, ASP.NET MVC, ASP.NET Core, API Integration, RESTful API and Node.js connected to CRMs, SaaS tools and external APIs
🔹 Cloud-based systems deployed on Microsoft Azure, Azure DevOps, CI/CD and Amazon Web Service with scalable backend architecture
🔹 Frontend interfaces using JavaScript, React, Angular, AngularJS, TypeScript, HTML, HTML5 and CSS with responsive Web Design
🔹 AI powered features using OpenAI API, OpenAI, Claude, Claude API, LangChain, FastAPI, RAG, Artificial Intelligence, Machine Learning and Natural Language Processing integrated into existing Web Application platforms
⚡ What Makes Me Different
Most developers build features. I build scalable systems.
As a Senior Full Stack Developer, I focus on:
🔹 API Development and RESTful API architecture using C#, .NET Core, ASP.NET Core and ASP.NET MVC
🔹 Complex API Integration across enterprise systems using Microsoft Azure and Azure DevOps
🔹 High-performance Microsoft SQL Server, PostgreSQL and SQL optimization
🔹 Cloud-native deployment using Microsoft Azure, Azure DevOps, CI/CD and Amazon Web Service
🔹 Full-stack Web Development using JavaScript, React, Angular, AngularJS, TypeScript, HTML, HTML5 and CSS
🔹 AI powered automation, ai agent workflows and AI Integration using OpenAI API, OpenAI, Claude, Claude API, LangChain and FastAPI
I design systems where C#, ASP.NET Core, .NET Core, Microsoft SQL Server, PostgreSQL, SQL, React, Angular and Microsoft Azure work as a unified architecture. My focus is production-grade Web Application systems with clean API Integration, scalable infrastructure and maintainable backend architecture built with C#, .NET Framework, ASP.NET, ASP.NET Core and ASP.NET MVC.
⚡ Core Stack
C#, .NET Core, .NET Framework, ASP.NET, ASP.NET Core, ASP.NET MVC, JavaScript, React, Angular, AngularJS, TypeScript, Node.js, PHP, Python, HTML, HTML5, CSS, SQL, Microsoft SQL Server, PostgreSQL, Microsoft Azure, Azure DevOps, CI/CD, Amazon Web Service, API, API Development, RESTful API, API Integration, Web Development, Web Application, Web Design, OpenAI API, OpenAI, Claude, Claude API, LangChain, FastAPI, ai agent, ai automation, ai powered systems, RAG, Artificial Intelligence, Machine Learning, Natural Language Processing.
I am currently available for Web Development, API Development, API Integration, AI Integration, ai automation and enterprise .NET development using C#, ASP.NET Core, .NET Core, Microsoft SQL Server, PostgreSQL, Microsoft Azure, React and Angular.
.NET Core
.NET Framework
C#
ASP.NET
Microsoft SQL Server
Microsoft Azure
ASP.NET MVC
SQL
ASP.NET Core
Azure DevOps
Microsoft Team Foundation Server
Microsoft Teams
Microsoft Power Automate
Blazor
Microsoft Dynamics 365
OpenAI API
Artificial Intelligence
Machine Learning
Microsoft Certified Professional
Microsoft Azure SQL Database
Eder G.
Sevilla, Spain
$40/hr
5.0
1 jobs
Senior Software Engineer with 10 years of experience across industrial automation, IoT systems, enterprise backend platforms, and automotive/insurance data ecosystems. Strong background in C#, Java, SQL, and modern distributed architectures, evolving from industrial maintenance environments to enterprise-scale software systems
.NET Framework
Web Application
AI App Development
Web Development
ASP.NET
Java
C#
React
JavaScript
TypeScript
Docker
Jira
Desktop Application
Supabase
Google Cloud Platform
Web Hosting
CI/CD
React Native
Flutter
Mobile App
FELIPE L.
Madrid, Spain
$25/hr
4.8
6 jobs
With over 25 years of experience as a Software Engineer.
Has been involved in more than 40 full cycle system and acting as principal developer/architect.
Assumed responsibilities like Application Developer, Database Designer or Administrator, Server Administrator, Development Manager, and Architect in a wide variety of business applications.
Particularly interested in developing enterprise-scale applications.
Can develop full-cycle applications by himself but also loves to join development teams.
Specialties: Can work in any phases of the SDLC using Microsoft .Net technologies such as C#, ASP.Net Core, Java, Phyton, Javascript, Typescript and Angular.
.NET Core
.NET Framework
JavaScript
Automation Anywhere
TypeScript
ASP.NET
Angular 6
C#
Dmitrii S.
Valencia, Spain
$60/hr
5.0
27 jobs
I'm a full-stack developer, 20 years of React and Node. Most of my work now is AI agents, LLM workflows and automation for Healthcare and MarTech companies, plus the systems that run them. The last AI pipeline I built serves 13,000 users.
Where I've worked
• Healthcare, four platforms between 2016 and 2025: dental imaging, workforce management for care providers, veterinary diagnostics (that one ran 32 months), and moving a US medical network off its legacy stack onto Azure. Clinical software is unforgiving about correctness and audit trails, so that is where I start.
• MarTech, three clients since 2025 and two of them still running: an ORM agency's internal platform, attribution and real-time analytics microservices for a B2B ABM platform, and ad reporting at volume.
AI I've shipped
• A driving-theory exam app I built from nothing. React Native on iOS and Android, React on the web, Nest.js behind both, 13,000 users. Underneath it there's a RAG pipeline that writes and checks a library of 5,000+ questions against a syllabus the regulator rewrites every year, with AI image generation and Spanish/English translation feeding the same content flow.
• An ORM agency that was running its whole operation out of Google Sheets. I moved it onto Supabase and PostgreSQL, built the app in Next.js and Node, then added AI flows on OpenAI and Edge Functions that took over monitoring and reporting people had been doing by hand.
What usually goes wrong with AI projects
The ones I've watched stall didn't stall on the model. It was auth, or getting at the data, or cost, or nobody being able to say what the thing did last Tuesday. That is ordinary engineering, and it happens to be what I've spent two decades on, a good part of it in regulated places where a security review is part of shipping. I'll also say when AI is the wrong tool for a job, since a plain script that costs nothing often does the same work.
Stack: LangGraph, OpenAI API, Node.js, TypeScript, React, Next.js, Nest.js, React Native, PostgreSQL, Supabase, MSSQL, MongoDB, Azure, CI/CD.
Send me the brief if you're automating a process or putting AI into a Healthcare or MarTech product, and I'll tell you how I'd approach it. I work hours that overlap the US and Europe, and I do the building myself.
.NET Core
.NET Framework
React
Next.js
TypeScript
Web Development
Web Application
Database Design
Microsoft Azure
Node.js
MongoDB
OpenAI API
Supabase
PostgreSQL
AI App Development
Website Performance Optimization
AI Development
AI Builder
Fahri K.
Barcelona, Spain
$50/hr
5.0
1 jobs
I help businesses streamline operations, modernize legacy workflows, and build reliable custom software using AI-assisted development, automation, and data-driven systems.
With 25+ years of experience in software development and business process consulting, I combine deep ERP/MRP expertise with modern AI-enabled engineering practices to deliver solutions faster, with strong attention to quality, scalability, and real business outcomes.
I specialize in:
• AI-assisted software development and workflow automation
• AI-powered analytics, internal tools, and decision-support workflows
• API integrations, ETL pipelines, and business automation
• ERP/MRP implementation, customization, and optimization
• Business process analysis and digital transformation
• C# / .NET, ASP.NET Core, and Blazor application development
• PostgreSQL and SQL Server database design, optimization, and reporting
• Financial software, trading tools, and market-data platforms
• Stock screening, technical analysis, and market-monitoring systems
Technical expertise:
• AI-assisted development workflows, LLM integrations, and automation
• TradingView, financial APIs, market data, and analytics
• Cloud-based business applications
• REST APIs and third-party system integrations
• C#, .NET, ASP.NET Core, Blazor
• Python for automation, data processing, and AI integrations
• PostgreSQL, SQL Server, database performance tuning
Recent project examples:
✔ Stock screening and technical-analysis applications
✔ AI-assisted workflow automation to reduce repetitive operational work
✔ ERP/MRP consulting and implementation for manufacturing businesses
✔ Custom inventory, production planning, and reporting systems
✔ Financial market-data collection and processing platforms
✔ Automated trading and market-monitoring tools
✔ Database performance optimization and reporting projects
My approach is practical and business-focused: I use AI where it creates real value—accelerating development, automating repetitive work, improving analysis, and helping teams make better decisions. The goal is always the same: efficient, maintainable software that produces measurable results.
If you need an ERP consultant, database specialist, AI-enabled software developer, financial software engineer, or automation expert, I’d be glad to discuss your project.
.NET Core
C#
ASP.NET
PostgreSQL
Python
Firebird
SQL
API Integration
Blazor
Trading Automation
PostgreSQL Programming
ERP Software
SQL Programming
DevExpress Reporting
ETL
Data Scraping
AI App Development
Serhii S.
Barcelona, Spain
$50/hr
5.0
1 jobs
With over 15 years in mobile game development, I focus on creating systems that are both scalable and maintainable. My experience spans Unity and software architecture, applying both Data-Oriented Design (ECS) and Object-Oriented Design (OOP) to solve complex challenges. I’ve contributed to large-scale projects with millions of players worldwide, always ensuring performance and stability through feature flags, safe rollouts, and thoughtful system design.
.NET Core
Unity
C#
iOS
Swift
Game
Solidity
Blockchain
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