The Modular Monolith Boundary I Couldn't Take Back
This title could be clearer and more informative.Try out Clickbait Shieldfor free (5 uses left this month).
A first-hand account of how a well-intentioned modular monolith boundary between a Catalog and Collaboration module gradually became irreversible. The author explains how asynchronous, event-driven communication between modules was the right call initially, but a later business requirement for immediate consistency forced synchronous calls and shared transactions, effectively merging the modules in practice while the boundary remained on paper. Key lessons: treat module boundaries as provisional guesses, start with fewer coarser modules and split only when seams are obvious, and let consistency requirements drive boundary decisions rather than domain intuition alone.
Table of contents
The SetupThe Slow SnowballThe Assumption That Aged BadlyThe Signals That Didn't Look Like SignalsWhat I'd Tell My Past SelfThe Part That's UncomfortableSummary115.1K Impressions1 Comment