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

Understanding the C# `StringValues`: A Comprehensive Guide

Understanding the C# `StringValues`: A Comprehensive Guide

In C#, the StringValues struct belongs to the Microsoft.Extensions.Primitives namespace, which is widely used in modern .NET applications. This struct plays a crucial role in efficiently managing string collections, especially when handling efficiently, particularly in contexts where multiple strings are involved. In this blog post, we’ll explore the purpose, usage, and key features of the StringValues struct in C#.

Managing Errors, Warnings, and Configurations in C# and .NET

Managing Errors, Warnings, and Configurations in C# and .NET

When we activated static code analysis for the first time in one of my last projects, the overwhelming number of warnings exceeded expectations and highlighted gaps in the code. Without making any changes, the project already had a significant number of warnings. After activating additional analyzers and updating some configurations, this number temporarily increased dramatically.

The high number of warnings was initially daunting, but we saw it as an opportunity to significantly improve our code quality. At first glance, it seemed easier to suppress or ignore these warnings. But as I often remind my team, “The code you create is a valuable legacy, so it’s important to build it carefully.” Ignoring warnings today creates obstacles for future developers—and that could very well include you six months down the line.

This experience reinforced the importance of managing warnings and errors systematically. Let me share some of the lessons we learned, the strategies we used to tame those 60,000 warnings, and how you can apply these techniques to your own projects.

A Tale of Forgotten Pennies and Lost Dollars

A Tale of Forgotten Pennies and Lost Dollars

In software development, there’s a silent debt that accrues interest over time, often hidden beneath layers of code and decisions made in haste or ignorance. This debt is aptly termed technical debt. Much like the german proverb, “Wer den Pfennig nicht ehrt, ist den Taler nicht wert”, (or the english equivalent, “A penny saved is a penny earned”) technical debt reminds us that small oversights or compromises in the present can snowball into significant challenges down the road. This article critically examines the parallels between financial principles and technical debt, emphasizing the importance of addressing both direct and indirect debt while understanding its distinction from external risks such as hacking or abuse.

dependamerge-action: Automated Dependency Merging

dependamerge-action: Automated Dependency Merging

In software development, dependencies are inevitable - any project worth its salt relies on various libraries, frameworks, or packages. However, as I found in my own work, managing these dependencies can be an onerous task. Constant updates, new vulnerabilities, and endless manual approvals were draining my time and focus. What if, I thought, these processes could be automated? This thought led to the creation of dependamerge, a GitHub Action designed to free developers from the drudgery of manual dependency maintenance and let us get back to what we do best: building great software.

Introducing Nullability in Legacy .NET Code

Introducing Nullability in Legacy .NET Code

As developers, we’re often tasked with maintaining and modernizing legacy codebases that were written long before some of the best practices of today—such as nullability annotations—were available. While modern C# now supports nullable reference types, enabling us to avoid the dreaded NullReferenceException, introducing this feature to existing, large codebases can be a challenge.

In this article, I’ll share my step-by-step approach for introducing nullability into a legacy .NET and C# project. You’ll learn how to apply nullability in a controlled, incremental manner using project-level settings, scoped annotations, and file/method-level directives, all while maintaining the integrity of your legacy codebase. After all, modernizing your code doesn’t have to be an all-or-nothing endeavor—gradual change is key to a successful transition. Let’s get started!