Hire the Best .NET Core Developers in Buenos Aires, AR

I’m a Full Stack Software Developer with over 20 years of experience specializing in Microsoft technologies, including .NET, C#, and SQL. I help businesses build scalable, reliable applications and solve complex technical problems with clarity and efficiency. Over the years, I’ve delivered a wide range of solutions across web, desktop, and cloud platforms. While my professional focus has always been within the Microsoft ecosystem, I’ve also explored Python through personal projects, particularly for scripting, automation, and AI experimentation. This gives me added flexibility and a broader perspective when designing solutions. What sets me apart is my calm, focused approach to problem-solving. I’ve led development efforts in high-pressure environments while remaining solution-oriented and easy to work with. Clear communication is a priority for me, and I make sure clients stay informed, aligned, and confident throughout the process. If you’re looking for a senior developer who brings deep Microsoft expertise, practical experience, and clear thinking to the table, I’d be happy to help move your project forward.

👨‍💻 About Me I'm a Senior Software Engineer & Technical Leader with over 8 years of experience delivering scalable, high-performance web applications and APIs. I specialize in Next.js, React, NodeJS, .NET Core and Angular. 🧩 Core Skills Frontend: React, Angular, Next.js, Bootstrap, MUI Datagrid, Tailwind CSS Backend: .NET Core, Node.js Databases: SQL Server, MongoDB, Redis Dev Tools: Git, Azure DevOps, Docker, CI/CD pipelines 🔌 API Integration Expertise I have extensive experience integrating third-party services like: Stripe (payments) Calendly (scheduling) Auth0 (authentication) Facebook API (social platforms) These integrations are implemented with performance, security, and long-term maintainability in mind. 👥 Leadership Experience As a Technical Leader, I’ve: Led a team of 10 developers on an e-commerce builder platform Designed software architecture and improved backend performance Prioritized product requirements with stakeholders Conducted code reviews and mentored junior developers ✅ What You Can Expect Clean, maintainable code Reliable API integrations Performance-focused backend systems Clear communication and on-time delivery Let’s work together to bring your product vision to life!

Hi! I'm Nati, a Senior Full-Stack Developer and AI Engineer with 10+ years building production systems for enterprise, healthcare, real estate, and high-growth startups. My background includes long-term work as a Software Engineer inside a diplomatic mission environment, where security, compliance, auditability, and documentation are mandatory. That discipline is the foundation of every project I deliver. Security and compliance as the first pillar. I have worked under strict government data governance standards, handled sensitive personal and financial data, and built applications that pass formal review processes. I also have direct experience delivering healthcare-adjacent systems with HIPAA-aware patterns: secure session handling, role-based access control, encrypted storage, audit logging, least-privilege architecture, and proper handling of PII and PHI. If your project involves sensitive data, I already speak that language. » What I build ↳ Full-stack web and mobile applications Next.js 14/15 (App Router, Server Components, Server Actions), React 19, TypeScript, Node.js, Python (FastAPI, Flask, Django), .NET Core, Laravel. Mobile with React Native and Expo. Production-ready from day one, not just demos. ↳ AI integration and LLM systems Multi-model orchestration across OpenAI, Anthropic Claude, and OpenRouter. Vercel AI SDK for streaming, tools, and agents. RAG pipelines with embeddings and pgvector. SSE streaming, cost optimization, model routing, structured outputs, and prompt engineering at scale. Experience integrating LLMs into platforms serving tens of thousands of users. ↳ AI-powered automation across the business I do not limit automation to engineering teams. I design and deploy AI agents and workflows that replace manual processes in finance, operations, HR, and admin: document processing, approvals, reporting, internal chatbots, and intake systems. I build the tool, write the documentation, and onboard the non-technical teams that will use it. ↳ Complex calculations and data-heavy backends Pricing engines, payroll and deduction systems, real estate valuation logic, analytics dashboards, and reporting platforms. I have built calculation-heavy systems where every number has to reconcile, audit, and survive review. Performance-tuned queries, well-modeled schemas, and clear validation rules. ↳ Migrations and platform consolidation I have migrated production applications from no-code and low-code stacks (Bubble, Lovable, v0, Retool, WordPress) into proper Next.js and Supabase or FastAPI architectures. If your MVP was built fast and now needs to scale, I do this exact kind of rebuild without losing the business logic that already works. ↳ Architecture, technical leadership, and code review Senior-level PR reviews, enforcing best practices on AI-generated code, defining technical roadmaps, mentoring developers, and owning delivery. I do not just write code, I make sure the product ships and is maintainable six months later. » Tech stack • Frontend: Next.js, React, React Native, Expo, TypeScript, Tailwind CSS, shadcn/ui, Framer Motion, Three.js, Redux Toolkit, React Query, GSAP. • Backend: Node.js, Express, Python (FastAPI, Flask, Django), ASP.NET Core, Entity Framework Core, Laravel, RESTful API design, JWT, OAuth, server-sent events, webhooks. • Databases: PostgreSQL, MySQL, SQL Server, MongoDB, Supabase (Auth, RLS, Storage, Edge Functions), Firebase, Drizzle ORM, SQLAlchemy, pgvector. • AI/ML: OpenAI API, Anthropic Claude API, OpenRouter, Vercel AI SDK, LangGraph, n8n, embeddings, RAG, vector search, agent orchestration. • No-code and low-code migration sources: Bubble, Lovable, v0, Retool, WordPress, Power Apps, Power Automate, SharePoint. • DevOps and infrastructure: Docker, Docker Compose, GitHub Actions, Azure, Azure DevOps, AWS, DigitalOcean, Hostinger, Vercel, NGINX, Let's Encrypt SSL, DNS management, CI/CD pipelines. • Testing and quality: NUnit, Moq, FluentAssertions, unit and e2e testing, code review standards. » Why clients hire me Enterprise-grade rigor: I have built and maintained production systems in highly regulated environments with strict documentation and security standards. That discipline carries into every client engagement. Senior judgment: I am not learning on your project. I have already built multi-tenant SaaS platforms, AI integrations at scale, calculation-heavy financial logic, real estate pricing systems, and healthcare-adjacent applications. I know which corners are safe to cut and which are not. Clear communication in English and Spanish. Honest about scope and availability: I disclose constraints upfront, flag mismatches early, and prefer projects where expectations are aligned from day one. If you are building something where the stakes are real, where data is sensitive, where the math has to be right, or where an MVP needs to grow into a real product, let's talk.

About Me I'm Fernando De Sena, a seasoned IT professional with a career spanning since 2004. My focus is on leveraging technological innovation to deliver the best solutions tailored to project needs and possibilities. Professional Experience For several years, I have worked as a developer specializing in C# with a strong emphasis on .Net Core and Entity Framework, alongside extensive experience with SQL Server databases. My expertise extends to full frameworks (versions 1.1, 2.0, 3.5, 4.0, 4.5) that preceded .Net Core, and I have also utilized MySQL and MongoDB in recent projects. Over the past six years, all my projects have been hosted on AWS, including: - A Finance PFM - A Fintech Banking CORE - A BTBTC application for well-being content with live streaming In recent years, I've also served as CTO for several companies, where I built products from scratch, led the hiring of entire dev teams, created comprehensive project roadmaps, and successfully achieved project milestones. My Team Today, I'm the co-founder of Spinlab, alongside other experienced professionals. Our DevTeam is based in Buenos Aires, and we're equipped to handle projects as a cohesive unit. Our expertise includes development, project management, and product discovery & UI/UX design, enabling us to take on MVPs and build projects from the ground up. Tech Stack Frontend: React, TypeScript, NextJS, Storybook, Jest, TailwindCSS, Eslint Backend: Node, NestJS, Jest, Yarn, Eslint Database: MongoDB, SQL (SQL Server, MySQL, Aurora, etc.) Cloud Architecture: AWS Additional Skills My experience also includes system integrations using REST and SOAP services, and working with RFID and other input/output sensors. Let’s Connect I’m always eager to explore new opportunities and bring innovative ideas to life. Feel free to reach out to discuss how we can collaborate on your next project.

Web and Web applications designs and development in a variety of technologies including AngularJS, Flask, Javascript, Prestashop, Bootstrap, NodeJS, MySQL, SQL among others. Any frontend and backend needs can be developed in a custom fashion according to your specific needs. I have a perfect understanding of how liquid, JavaScript, HTML and CSS work, and have a lot of experience working with all of them. I can build adaptive and high-quality layouts on your design or adapt the website to your corporate identity. I also offer Ecommerce solutions for businesses of any size in the Prestashop platform. Maintenance, development and design in this platform is available.

I’m a passionate and detail-oriented .NET Web Developer with over X years of experience building reliable, scalable, and high-performance web applications. I specialize in C#, ASP.NET MVC/Core, SQL Server, and modern frontend tools. I work closely with clients to bring their ideas to life with clean, efficient, and well-documented code. Let’s build something great together.