Architecture as feedback
Moving decisions out of static diagrams and into deterministic checks that run with ordinary tests and pull requests.
Creator and maintainer
Lukas Niessen
Lukas started ArchUnitTS to solve a real architecture-testing gap and now stewards the shared direction across the library family.
View GitHub profile ↗
About Lukas
Turning architectural intent into a testable interface.
Lukas created ArchUnitTS after encountering a practical gap on a consulting project: TypeScript teams could describe architectural boundaries, but they lacked a sufficiently capable way to test those decisions inside the delivery loop.
What began as a focused dependency-rule library developed into a broader family of language-native tools. Lukas works across their product direction, implementation model, release quality, documentation, and the shared vocabulary that makes an ArchUnit rule recognizable without making every ecosystem behave identically.
His focus is the distance between an architectural idea and useful feedback. A rule should read clearly in code, evaluate the project the team actually ships, and return enough evidence for a developer or coding agent to correct the violation without reverse-engineering the test.
Published work
Ideas from Lukas.
TypeScript14 min read
ArchUnitTS vs. tsarch in 2026: which architecture test should you choose?
A hands-on comparison of maintenance, correctness, project resolution, features, and performance for TypeScript architecture testing.
Read article ↗Architecture12 min read
Fitness functions for AI-generated code
Why deterministic architecture feedback matters when software changes faster than humans can review every edge.
Read article ↗Python15 min read
Architecture testing for fast-growing Python systems
How executable boundaries help Python services, data platforms, and AI projects grow without losing their shape.
Read article ↗TypeScript11 min read
Architecture tests and lint rules solve different problems
A practical guide to choosing editor-fast import rules, graph-aware architecture tests, or both.
Read article ↗Project12 min read
Why ArchUnitTS exists
The practical need that started one TypeScript library and grew into an architecture-testing family.
Read article ↗Focus
Where Lukas contributes.
Cross-ecosystem coherence
Keeping a shared mental model across TypeScript, Python, .NET, Ruby, Rust, Zig, Go, Java, and PHP while respecting each language.
Delivery quality
Treating documentation, release integrity, self-testing, CI, reports, and performance as parts of the product rather than finishing work.
Selected project work
Work that makes the library family stronger.
- 01
Created ArchUnitTS and developed the original fluent architecture-testing model.
- 02
Stewards the expansion from dependency rules into layers, slices, metrics, diagrams, structured reports, and ecosystem integrations.
- 03
Coordinates the shared direction and release quality of the wider ArchUnit library family.
Working principle
“An architecture rule earns its place when it is precise enough to trust and clear enough to act on.”
Contact Lukas
Ready to make architecture visible?
Talk with Lukas about architecture testing, the ArchUnit library family, or how executable guardrails can fit your engineering workflow.
lks.niessen@gmail.com
