Martin Stühmer — CTO, Enterprise Architect & DevOps Engineer

Who I Am

I’m Martin, CTO at Integrated Worlds GmbH in the Stuttgart region. I’ve been writing production .NET code since Framework 2.0 — back when SOAP was still considered modern and ORMs were a heated debate. A lot has changed since then. My opinions have changed too, usually because I was wrong about something.

Before Integrated Worlds, I was Director of Consulting Services at CGI, leading teams through architecture decisions and digital transformation projects across multiple industries. These days I set technology strategy and stay close enough to the code to feel the consequences of those decisions firsthand.

I’m a Microsoft Certified Trainer and IHK-certified instructor, maintain several open-source NuGet packages, and write about what I’ve actually learned rather than what sounds good in theory.

LinkedIn · GitHub · Bluesky

What I Know Well

Nearly two decades of production work leaves marks. Here’s where I’ve built up depth and, frankly, strong opinions:

.NET and C# — I’ve tracked this ecosystem from the framework era to .NET 10. Source generators, Roslyn analyzers, performance engineering, testing strategies, static analysis. I know what actually improved over the years and what just changed names.

Cloud-native architecture on Azure — AKS at scale, multi-cluster networking, zero-downtime upgrade strategies, cost governance, observability. I’ve spent enough time in Azure to know the gap between what it can do and what you should actually use.

DevOps and supply-chain security — GitHub Actions, dependency management, container security, Bicep-based infrastructure compliance. The organisational side matters as much as the tooling.

Application security and privacy — Azure Key Vault, managed identities, GDPR-relevant .NET patterns, data minimisation, AI coding tool content exclusions. Security that works in practice, not just in architecture diagrams.

Engineering culture — What AI coding assistants actually change about software quality (less than the hype, more than the skeptics admit), how to introduce static analysis without poisoning team morale, and when “best practices” are earned principles versus cargo-cult repetition.

How I Work

As CTO I stay close to the code. I write, review PRs, debug production issues, and mentor — because technology leadership that operates purely from a distance eventually loses touch with the real cost of decisions.

As a trainer I focus on fundamentals that outlast the current framework cycle. Static analysis, testing discipline, performance patterns, maintainable architecture. The things that prevent fires, not just the things that look good in a job posting.

As an open-source maintainer I publish packages that solve problems I’ve hit repeatedly. Knowing that strangers depend on your code is one of the better ways to raise your standards.

What I’ve Learned the Hard Way

I’ve over-engineered systems that should have been simple. I bet on Silverlight and WCF. I built “flexible” architectures that were really just complicated ones. I’ve shipped code I’m not proud of.

Here’s what held up after all that:

  • Quality isn’t optional — analyzers find bugs in milliseconds, tests prevent regressions, and neither is slower than a production incident
  • Fundamentals outlast frameworks — the patterns and principles stick around long after the tools are deprecated
  • Context beats dogma — “best practices” always depend on your team, domain, and actual constraints
  • Evidence beats intuition — measure, benchmark, validate; don’t just decide
  • Pragmatism wins — architecture that ships beats architecture that’s perfect on paper

What I Write About

Everything here comes from production systems and real teams, not documentation rewrites. I’m skeptical of buzzword-driven development and allergic to advice that’s never been tested under load or deadline. If something doesn’t hold up, I’ll say so.

The topics I keep returning to: .NET and C# performance and evolution, Azure and AKS architecture decisions, DevOps and supply-chain risk, application security and GDPR implementation, what AI coding tools actually change (and what they don’t), and the economics of technical debt and code quality.

I write for developers, architects, and operators who maintain production systems and care about getting it right — not just getting it shipped.

The code you create is a valuable legacy, so it’s important to build it carefully.

Published blogs

EF Core Plugins: Owning Migrations with ExcludeFromMigrations

EF Core Plugins: Owning Migrations with ExcludeFromMigrations

ExcludeFromMigrations() keeps plugin entities fully queryable in the host DbContext while stripping migration ownership of their tables. Combined with per-context migration history tables, IDesignTimeDbContextFactory, and an explicit application-layer data access pattern, it enables truly independent plugin schema evolution.
EF Core Plugins: When Migrations Go Wrong

EF Core Plugins: When Migrations Go Wrong

EF Core’s entity discovery is thorough by design. In a plugin architecture, that thoroughness becomes a liability: navigation properties pull plugin entities into the host migration, creating shared schema ownership that breaks plugin isolation, causes schema drift, and makes clean plugin uninstalls impossible.
Building an MCP Server in .NET Without Buying the Hype

Building an MCP Server in .NET Without Buying the Hype

MCP is JSON-RPC with conventions, not magic. This guide builds a Model Context Protocol server in .NET with the official SDK: stdio and Streamable HTTP transports, tightly-scoped typed tools, JWT authentication, prompt-injection defenses, OpenTelemetry tracing, and the production failure modes the demos never mention.
Structured Logging Patterns That Actually Survive Production

Structured Logging Patterns That Actually Survive Production

Every pattern here addresses a failure mode I have either shipped or inherited. Source generators on hot paths, scope opt-in per provider, end-to-end correlation ID propagation, log levels as an ops contract, sink selection as an architecture decision, and OpenTelemetry Logs for greenfield services: six concrete changes that make structured logging trustworthy in production.
TimeProvider Test Patterns That Hold Up in CI and Production

TimeProvider Test Patterns That Hold Up in CI and Production

FakeTimeProvider gives you a clock you control. That solves the easy 30%. The hard part is everything that interacts with that clock: async callbacks, PeriodicTimer, CancellationTokenSource.CancelAfter, BackgroundService loops, and DI lifetime traps that turn deterministic bugs into apparently flaky tests.