I build and modernize .NET systems for multinational companies and the public sector, and I've done it for over 15 years, from VB 6.0 and ASP.NET to microservices on AWS. Today I pair that foundation with applied AI: assistants that cite their sources, agents that ask before they act, and pipelines where a rule checks every number the model returns. Each one ships with evals, a cost per call and the cases it still gets wrong.
Note
Built in public, measured in public. Every figure in the projects below comes from that repo's evals, tests or demo runs. The case studies, with video and screenshots, live at juangomezb.com.
The live portfolio at juangomezb.com · English and Spanish, light and dark
 booking-agent Appointments booked by chatting: the assistant holds the slot, the customer confirms with a button, and PostgreSQL makes double booking impossible. 1 of 50 simultaneous requests for one slot gets it · USD 0.0024 per conversation Case study · .NET 10 · SignalR · Claude Haiku 5.5 |
 data-chat Ask your sales spreadsheet in Spanish or English: the figure, a chart and how it was computed. The AI never writes SQL; the server does, read-only. 75/75 eval questions right · 20/20 injection attempts with no effect Case study · .NET 10 · PostgreSQL · Recharts |
 docs-assistant A support assistant that answers from your documents, cites every answer, and hands the conversation to a person when it doesn't know. 98% retrieval hit@5 on a bilingual eval · 12/12 prompt injections resisted Case study · .NET 10 · pgvector · 9 KB widget |
 invoice-extractor Turns photos and PDFs of invoices into rows ready for the books: Claude reads them, accounting rules check every number, and what doesn't add up goes to a person. 0/42 false auto-approvals · USD 0.00065 per document Case study · .NET 10 · Claude vision · Excel export |
 dotnet-ai-template A GitHub template to start an AI product on .NET 10: enforced layers, the model behind a port, every call metered and capped, evals and E2E in CI. 36 tests with no key and no cost in CI · extracted from 4 shipped projects Case study · Microsoft.Extensions.AI · Aspire |
 talent-mcp An MCP server in C# that gives AI agents typed, secured tools for recruiting, on the session-less 2026-07-28 protocol revision. 6 tools, each behind its own OAuth scope · 323 ms cold start, measured in CI Case study · MCP · OAuth 2.1 · OpenTelemetry |
 claude-pr-review-bot A pull request reviewer for GitHub Actions that asks Claude for one document of findings, and can only ever comment. 3/3 bugs flagged in a real demo PR · USD 0.0009 for that review Case study · GitHub Actions · structured outputs |
More on the portfolio Every project has a case study with the architecture, the decisions and their trade-offs, the evals and what each call costs. All projects → |
 Applied AI RAG on PostgreSQL and pgvector, MCP servers and agents with Claude behind Microsoft.Extensions.AI. Evals, spending caps and prompt-injection defenses. |
 Backend & architecture .NET, C#, Node.js and NestJS. Microservices, microfrontends, message queues, Clean Architecture and DDD. |
 Legacy modernization ASP.NET to .NET Core, VB 6.0 to modern stacks, desktop apps to the web, without stopping the business. |
 Frontend React, Next.js, Angular and TypeScript: accessible, responsive interfaces, tested end to end with Playwright. |
 Cloud & DevOps AWS in production, Azure, Docker and .NET Aspire. CI/CD that cut deployment times by ~25%. |
 Leadership Technical lead for distributed, multinational teams, with Agile practices and code that the next person can own. |
Software Engineer @ The Stepstone Group (Jan 2022 – Present) · 🇬🇧 United Kingdom
Digital recruitment platforms across 6 international brands serving Europe, Central America, and the Caribbean
- 🚀 Architected and implemented microfrontends, microservices, and messaging queues improving scalability
- ⚡ Reduced deployment times by ~25% through automation and CI/CD optimization
- 🎨 Enhanced UX and redesigned multiple brand interfaces, receiving positive user feedback
- 🐛 Resolved critical bugs and delivered business-driven features aligned with pricing strategy
- ☁️ Ensured high availability and performance of services on AWS infrastructure
Tech Stack: React, .NET Core, AWS, Microservices, Message Queues, CI/CD
.NET Developer @ Axxis-Systems (Jun 2020 – Dec 2021) · 🇳🇮 Nicaragua
Core insurance platforms for clients across Latin America and Europe
- 📈 Improved operational efficiency by ~15% through automation and system enhancements
- ⚡ Enhanced platform usability and reduced load times by ~20% using ExtJS optimizations
- 🧮 Designed complex calculations for insurance policies handling large datasets and business rules
- 🛠️ Delivered bug fixes and business-critical features ensuring system reliability
Tech Stack: .NET, ExtJS, JavaScript, SQL Server, Insurance Domain
Team Leader @ INIFOM · 🇳🇮 Nicaragua
Software solutions for all 153 municipalities across Nicaragua supporting public sector operations
- 🔧 Led implementation of Team Foundation Server (TFS) improving collaboration and code management
- 🚀 Migrated legacy ASP.NET applications to .NET Core enhancing performance and security
- 🖥️ Managed servers and infrastructure: IIS, SQL Server, Reporting Services, TFS administration
- 🛡️ Provided ongoing support for VB 6.0 legacy systems ensuring business continuity
Tech Stack: .NET Core, ASP.NET, VB 6.0, SQL Server, TFS, IIS
Software Developer @ Attorney General's Office (Mar 2014 – Apr 2017) · 🇳🇮 Nicaragua / 🇵🇦 Panama
National cadastre system for 153 municipal governments
- 🏛️ Led development of nationwide cadastre system (SISCAT) enabling efficient territorial management
- 🔗 Integrated municipal and physical cadastre systems (SISCAT + SISCAF) for centralized administration
- 💰 Coordinated taxpayer data migration to financial systems improving municipal revenue collection
Tech Stack: .NET, SQL Server, GIS Systems, Government/Public Sector
Web & .NET Developer @ Managua's Town Hall (Jan 2010 – Mar 2014) · 🇳🇮 Nicaragua
Strategic planning and project management systems for municipal government
- 📋 Developed Strategic Planning System using ASP MVC for centralized plan management
- 🚀 Created Project Formulation System streamlining project creation and monitoring
- 🔄 Migrated desktop application to web-based platform enhancing accessibility and collaboration
Tech Stack: ASP.NET MVC, C#, SQL Server, Web Development
| AI | Backend | Frontend | Cloud & DevOps | Data |
|---|---|---|---|---|
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
- Architecture: microservices, microfrontends, event-driven design, DDD, Clean Architecture
- Practices: Agile/Scrum, CI/CD, TDD, evals for every AI feature
- Languages: Spanish (native), English (B1)
Earlier open-source work
- .NET Core Microservice Architecture – event-driven microservices with RabbitMQ, MongoDB and Docker
- NestJS GraphQL API – backend starter with DDD, TypeORM and PostgreSQL
- ReactJS Pro Components – compound components, control props and extensible styles
- NodeJS REST API – modular REST API with JWT authentication
- Covid-19 Cases Tracker – pandemic dashboard with Chart.js and a REST API
- ReactJS Fundamentals – core React concepts with practical examples
Bachelor's Degree in Software Engineering · Central American University (UCA), Nicaragua · 2007 – 2011
I'm open to Senior/Staff Engineer roles and remote positions, and I take on freelance projects where a business needs a .NET system with AI it can trust: a support assistant, document extraction, bookings, or questions over its own data. Write to me at gb.jc@outlook.com or on LinkedIn.
Juan Gómez · juangomezb.com · LinkedIn · DEV
Artwork generated by scripts/readme-assets.mjs (npm install && npm run readme:assets) · icons from Lucide (ISC)