Senior .NET developer specialized in SQL Server, performance and observability

We are a European software development company with an ERP comprising about forty modules. It is a database-intensive system that manages business-critical processes with legal consequences. • CAPA LEGACY: a proprietary 4GL platform that is still in operation. You will not be working directly with it in this position. • CAPA MODERNA: a web application built with .NET 10 and Blazor Server, with SQL Server as the database. This is where you will be working. We are looking for a full-time Senior .NET Specialist to work on our web application, with a particular focus on SQL Server, performance, and observability. This is a hands-on role. You will work alongside the architect responsible for the technical strategy, so we are looking for someone dependable and determined, even if you don't have principal architect experience. The web application needs improvements in performance, stability, and diagnostics. SQL Server is involved in many business processes, and there are opportunities for improving queries, data access patterns, indexes, transactions, concurrency, and observability. We need someone who can investigate real-world problems end-to-end, from .NET code to execution plan, and implement measurable solutions without turning every fix into a complete rewrite.

• Analyze slow queries, execution plans, indexes, statistics, locks, deadlocks, timeouts, and resource consumption
• Optimize data access from .NET, including parameterization, connection management, transactions, concurrency, and error handling
• Enhance application and SQL Server observability with structured logs, metrics, traces, dashboards, and useful alerts
• Investigate production incidents and find the root cause in the code, the database, or their interaction
• Safely implement optimizations, measure results, and avoid regressions
• Work with the architect and the rest of the team to prioritize and execute the technical plan
• Develop and maintain web application functionality using C#, .NET 10, and Blazor Server

Expected initial results

• Hands-on knowledge of the web application, its critical workflows, and data access patterns
• Baseline performance and observability for key SQL Server issues
• First optimizations confirmed by before-and-after metrics
• Prioritized backlog of improvements in .NET, data access, and SQL Server

Mandatory

• Solid professional experience with C# and .NET in production web applications
• Advanced experience with SQL Server, T-SQL, execution plans, indexing, statistics, and query optimization
• Ability to diagnose performance, locking, blocking, and concurrency issues
• Experience mapping .NET code behavior to its real-world impact on the database
• Practical understanding to prioritize, implement, and verify improvements in complex systems

Desired

• Experience with Blazor Server and .NET 10
• Experience with OpenTelemetry, Application Insights, Grafana, Datadog, or other observability tools
• Experience with ERP, business-critical systems, or database-intensive applications
• Familiarity with CI/CD, integration testing, and performance regression analysis