A precision rule engine for teams who need business logic they can see, test, and trust.
Business logic is everywhere: pricing rules, approval workflows, eligibility checks, commission calculations. Yet most teams handle it the same way—buried in application code, scattered across spreadsheets, or locked in expensive enterprise tools.
The result? Rules that only developers can change. Decisions that can't be explained. Updates that require full deployment cycles. And when something goes wrong, nobody can trace why.
STELLWERK makes business logic a first-class citizen—visible, testable, and independent from your application code.
Model logic as a graph of nodes. Anyone can read the flow—developers, product managers, compliance teams.
Same inputs always produce the same outputs. No side effects, no hidden state. Every execution is reproducible.
Execute flows via REST API from any language. JSON in, JSON out. No SDK required, no vendor lock-in.
Update rules instantly. No code changes, no release cycles. Test in sandbox, publish when ready.
Ronald and Adam
After years of building software for companies of all sizes, we kept running into the same problem: business logic that started simple but grew into an unmaintainable mess. Pricing rules scattered across services. Approval workflows that nobody fully understood. Every change required a developer, a code review, and a deployment.
We built STELLWERK to solve this. It is a tool where business rules are visible, testable, and changeable without touching application code. It's the system we wished we had on every project.
STELLWERK is currently in open beta. We believe in transparency—you should know where this product is heading.
Start building flows in minutes or even in seconds using AI. Free during beta.