JetBrains .NET Day Online 2026: Session Recordings Now Available
Explore expert-led sessions on AI agents, modular architecture, and .NET security practices.
1Event Overview and Availability
The JetBrains .NET Day Online 2026 took place on October 7, featuring a comprehensive series of technical sessions. All recorded presentations are now accessible on YouTube for developers who missed the live event. This collection serves as a primary resource for understanding current trends in .NET development and toolchain advancements.
2JetBrains Air and AI Agents
The keynote introduced JetBrains Air, an agentic tool designed to enhance developer productivity within Rider. Demonstrations showed how agents utilize bundled skills for debugging and refactoring code. By integrating profiling data, such as dottrace-analyze, the team successfully improved agent accuracy from 4.7 to 8.1 out of 10 during internal evaluations.
3Distributed Systems and Messaging
Irina Dominte explored essential patterns for distributed .NET systems, specifically focusing on Outbox, Inbox, and Saga implementations. The session analyzed the operational costs and benefits of each pattern in modern software solutions. These strategies are critical for maintaining data consistency and reliable communication across complex, decoupled service-oriented architectures in production.
4Performance and Native AOT
Stefan Pölz demonstrated how C# interceptors and incremental source generators can effectively replace reflection-based call sites. This approach significantly improves code trimming capabilities, making applications more compatible with Native AOT. These optimizations allow developers to achieve better performance metrics without sacrificing the flexibility required for modern, high-scale .NET application environments.
5Security and Supply Chain
Maarten Balliauw highlighted critical vulnerabilities within the .NET and NuGet ecosystems, drawing parallels to recent npm supply chain attacks. The presentation detailed various methods for code injection through MSBuild and NuGet packages. Attendees learned actionable strategies to mitigate these risks and secure their build pipelines against sophisticated external threats.
6Architectural Patterns and Scaling
Steve Smith and Eric Fleming advocated for the modular monolith as a balanced alternative to traditional monoliths and microservices. Meanwhile, Michael Washington presented the Blazor Data Orchestrator, built with .NET Aspire and Azure Container Apps. These sessions provide practical frameworks for managing codebase complexity while maintaining deployment simplicity across various environments.
7Data Interoperability and MCP
Sam Basu, Andres Pineda, and Jerry Nixon discussed the Model Context Protocol (MCP). The sessions covered building MCP servers with the C# SDK and introduced Microsoft's open-source SQL MCP server. These tools enable language models to securely interact with diverse databases like PostgreSQL and Cosmos DB while respecting existing permission policies.
8Community Feedback and Future
The event concluded with a call for community participation through a survey open until November 8. JetBrains emphasizes that this feedback directly influences the planning for future .NET Day events. By analyzing these responses, the organizers aim to refine their technical content and better serve the evolving needs of developers.