.NET modernization
Rebuild brittle systems without losing business rules, parity, or momentum.
Architecture. Modernization. AI with guardrails.
Long-term software solutions for teams tired of short-term fixes.
Michael Kappel brings 20+ years of experience building, repairing, and modernizing business-critical systems with ASP.NET Core, C#, TypeScript, EF Core, SQL Server, and carefully reviewed AI tooling.
This practice is built for companies that need more than quick code. It is for platforms that need to stay secure, testable, maintainable, and useful long after launch.
Practical automation
OpenAI and local LLM workflows that accelerate delivery without weakening quality.
Testable architecture
Unit testing, CI/CD, dependency management, and clear separation of concerns.
20+
years building enterprise and high-traffic software
.NET
architecture, APIs, Razor Pages, MVC, EF Core, SQL Server
AI
OpenAI, LM Studio, semantic search, documentation automation
Teams
mentoring, test strategy, agile delivery, quality improvement
What Longterm Software Solutions does
Engineering depth for the parts of software delivery that usually break first.
01
Legacy modernization
Translate aging platforms into current architectures while preserving business behavior, data integrity, and operational confidence.
02
Architecture and delivery rescue
Stabilize codebases, improve maintainability, untangle dependencies, and put sane technical direction back in place.
03
AI-assisted development
Integrate OpenAI and local LLM workflows for documentation, search, migration, and acceleration while keeping review standards high.
04
Mentoring and quality systems
Raise the bar with unit testing strategy, code review discipline, developer coaching, and architecture patterns teams can sustain.
Selected outcomes
Recent work drawn directly from the resume, translated into business impact.
Insurance platform modernization with parity testing
Rebuilt a dental insurance contract management system in .NET Core, C#, TypeScript, and EF Core, then automated side-by-side validation against existing claims adjudication logic.
Collaboration systems and Microsoft Graph integration
Built file-sharing and working-file collaboration in Microsoft Teams, combined with Azure Blob storage and asynchronous API integrations for faster, cleaner workflows.
Quality, SEO, APIs, and roadmap repair for complex web products
Improved error handling, testing strategy, CI/CD, API design, SEO structure, and long-range architecture across high-demand production systems.
How the work is approached
Move fast where it is safe. Slow down where it matters.
That balance runs through the resume and through this practice: speed matters, but maintainability, correctness, and operational clarity matter more. AI can help. Testing matters. Architecture matters. The system still has to make sense after the sprint ends.
Diagnose
Find the real constraint: architecture, testing gaps, legacy coupling, delivery process, or developer context loss.
Design
Choose the least risky path that still improves structure, quality, and future delivery speed.
Deliver
Ship with observability, testing discipline, and documentation that other people can actually use.
Best fit