Senior .NET Backend Consultant · AI Integration · Remote · B2B
Specialized .NET consultant for systems where complexity has already emerged — and AI integration into real production environments. 14 years as an independent contractor with real load, complex dependencies and operational pressure.
01 · Problems
Backend problems don't appear in diagrams. They appear in production, under load, at the worst possible moment.
The system works in staging. In production, under real volume, response times spike.
Every new feature takes twice as long as the previous one. The codebase is slowing the team down.
The system needs refactoring, but the business can't afford a halt.
Incidents are detected late, are hard to diagnose and nearly impossible to prevent.
Degraded performance, but hard to pinpoint: queries? application code? architecture?
The architecture handled the original volume. With current growth, it no longer does.
02 · Value proposition
I specialize in the point where the system is already in trouble: degraded performance, accumulated complexity, legacy systems under operational pressure. My approach is pragmatic: evidence-based diagnosis, surgical intervention, incremental improvement without unnecessary disruption.
I'm not:
03 · Services
Integration of LLMs and agentic workflows into .NET production systems. Configurable behavior via settings, auditable logic, production engineering standards. AI inside the system — not on top of it.
Diagnosis and resolution of bottlenecks at every level: SQL queries, application code, data pipelines and architecture. Analysis with evidence, not assumptions.
Intervention in systems under operational pressure. Incident analysis, root cause identification, observability improvements and operational risk reduction.
Incremental evolution of legacy systems and monoliths towards maintainable architectures. Without stopping the business or interrupting team delivery.
Direct participation as an embedded consultant. Bringing production experience, quality standards and additional technical capacity to the existing team.
Architecture review and code audit. Objective evaluation of system health with actionable, prioritized recommendations.
04 · Technical edge
BSc in Mathematics, University of Santiago de Compostela. A background that is not decorative: it translates directly into how I design systems, reason about complexity and make architectural decisions under uncertainty.
Degree
BSc in Mathematics
Universidad de Santiago de Compostela · 1993–1999
Coherent domain models with well-defined invariants
Reasoning about computational complexity applied to design decisions
Algorithmic rigor in optimization and performance analysis
Conceptual precision before writing code — not the other way around
05 · Methodology
I work with the processes, stack and business context that already exist. I don't impose methodologies or unsolicited structural changes.
Analysis starts from the production system, with real data under real load. Not idealized diagrams.
Incremental, reversible changes with measurable impact at each iteration. Without interrupting team delivery.
With the team and technical leadership. No ambiguity, no overselling, always with supporting evidence.
Any intervention improves the team's ability to understand, monitor and act on the system.
06 · Experience
Active production projects only, with real impact. Full CV available on request.
AI Integration · Own development
End-to-end design and development of a production-grade backend system integrating LLM-based analysis into real domain workflows. Clean Architecture, fully configurable AI behavior via settings, runtime scoring model. Chrome Extension for data capture, dockerized pipeline. The AI does not replace the workflow — it runs inside it.
.NET 8 · Claude API · SQL Server · Docker · Quartz · TypeScript
Fintech · MiFID2
Backend consultant on a multitenant SaaS platform for regulated financial advisory. Refactoring of critical components, performance optimization and per-tenant observability. Active production system with multiple modules: account management, portfolio reporting, advice engine and digital signature.
.NET 6/8 · ASP.NET Core · SQL Server · MongoDB · RabbitMQ · Redis · Docker
Air Logistics
Full design and development of an operational management system for an air handling operator. Covers the complete cycle: flights, manifests, rates, automated billing, storage and accounting. Sole technical owner from day one, system in active production.
.NET 5 · ASP.NET MVC · Azure App Service · Azure SQL
Automotive
Snowflake connector optimization and performance improvements on analytical dashboards over a microservices architecture. Fork and adaptation of the CData driver to resolve connectivity limitations in the client environment.
.NET Core 3.1 · Docker · Kubernetes · Snowflake
If the problem has already surfaced in production, it's time to talk. No commitment, no sales pitch.
Schedule a call07 · Contact
I work with teams that have a real backend problem. If that's your case, write to me.
Or write directly to
freelance@jmcasal.comFull CV available on request.