Martin Stühmer

Who I Am

I’m Martin, CTO at Integrated Worlds GmbH in the Stuttgart region. I’ve been building .NET systems for nearly 20 years—since Framework 2.0 when SOAP was cutting-edge and ORMs were controversial.

Today I lead technology strategy for cloud-native solutions on Azure. Before this, I was Director Consulting Services at CGI, working with enterprise teams on architecture and transformation. I’m a Microsoft Certified Trainer and IHK-certified instructor, and I maintain several open-source NuGet packages.

What I Do

As CTO, I don’t just make decisions from a distance. I write code, review PRs, debug production issues, and mentor teams. Technology leadership means staying hands-on and feeling the consequences of your choices.

As a trainer and mentor, I focus on fundamentals that outlast framework hype. Static analyzers, testing strategies, performance patterns, maintainable architecture—the stuff that actually prevents production fires.

As an open-source maintainer, I publish packages that solve problems I’ve hit repeatedly in real systems. When strangers depend on your code, you write better tests and clearer docs.

What I’ve Learned

Almost two decades means I’ve made every mistake: over-engineered systems, bet on Silverlight and WCF (oops), built “flexible” architectures that were just complicated, shipped code I’m not proud of.

Here’s what stuck:

Quality isn’t optional – Analyzers catch bugs in milliseconds, tests prevent regressions, and both are faster than firefighting
Fundamentals outlast frameworks – Patterns and principles survive; specific tools don’t always
Context beats dogma – “Best practices” depend on your team, domain, and constraints
Evidence beats opinion – Measure, benchmark, validate before deciding
Pragmatism wins – Good-enough architecture that ships beats perfect architecture that doesn’t

What I Write About

I share perspectives from production systems and real teams. I’m skeptical of buzzword-driven development and allergic to cargo-cult practices. If a trend lacks substance or a pattern doesn’t hold up under pressure, I’ll say so.

This blog is for developers, solution architects and operators who maintain production systems and care about quality, not just shipping fast.

Published blogs

Your Azure SQL Is Public Right Now. ISO 27017 Demands You Fix It

That SQL Server you deployed last week? Publicly accessible. That Storage Account? Same story. Azure defaults are security theater. ISO 27017 calls this a compliance violation, and your next audit will too. Stop trusting “cloud-native” to mean “secure” and start implementing VNets, Private Endpoints, and NSGs before your data becomes someone else’s problem.

Your Incident Response Plan Is a Lie. Here's How to Fix It.

That incident response plan in your Confluence? Nobody reads it. The on-call engineer can’t find it. And when your production API is bleeding at 3 AM, you’ll improvise—badly. ISO 27001 A.16 doesn’t care about your documentation theater. It demands procedures that work. GitHub Actions turns incident response from compliance fiction into executable reality.

Stop Hoarding Personal Data in Entity Framework

The classic monolithic User entity—stuffed with birth dates, phone numbers, employment history, and marital status “just in case”—turns into a compliance nightmare the moment someone requests data deletion. You can’t delete without breaking referential integrity. You can’t keep the data without violating GDPR. You can’t anonymize without retaining fields that should never have existed. The solution isn’t complex: separate operational data from personal data, make consent-based fields nullable and purpose-documented, implement soft deletes with query filters, and validate your API boundaries with integration tests that fail when unnecessary fields leak through. Data minimization isn’t regulatory overhead—it’s architectural hygiene that makes your deletion logic straightforward and your audit responses honest.

Your Encryption Is Broken — .NET Data Protection Done Right

Every developer who has tried simple encryption with XOR and hardcoded keys eventually faces the audit that exposes their house of cards. I’ve watched production systems fail compliance assessments because someone believed base64 encoding was good enough or that compilation obscures secrets. The .NET Data Protection API exists precisely because Microsoft’s cryptography team spent years solving problems most developers don’t know they have. This isn’t about learning yet another library—it’s about understanding why professional implementations outperform clever hacks, and how Azure Key Vault integration transforms theoretical security into auditable compliance.

Your appsettings.json Is a Compliance Violation

Hardcoded secrets aren’t just bad practice—they’re ISO 27017 violations with real consequences: failed audits, denied insurance claims, contractual penalties. That connection string in your appsettings.Production.json? It represents a compliance gap your organization probably doesn’t even know exists. Azure Key Vault with Managed Identity isn’t an optional security enhancement—it’s the minimum viable implementation of standards you already claim to follow.