I Built a Minimal Workflow Engine to Understand How n8n Works Under the Hood
Introduction I’ve been using n8n for quite some time now and couldn’t help wondering how it works under the hood, so I decided to build a minimal working version of the engine myself. This post covers how the engine handles execution order, the pluggable node system, expression evaluation, and the diamond merge pattern. You can find the full source code on GitHub. What is a Workflow Engine? Basically a workflow engine is just a graph where it has 2 or more nodes that have individual functions like “fetch this URL” or “check this condition”. These connections between nodes is what define the data flow. ...