--- title: Modular Monolith Boundaries Done Wrong | daily.dev description: Explains why modular monoliths often remain tightly coupled despite having clean project structures: teams tend to define physical boundaries (projects,... canonical: https://daily.dev/posts/modular-monolith-boundaries-done-wrong-4jnemg3nw twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: Modular Monolith Boundaries Done Wrong | daily.dev og:description: Explains why modular monoliths often remain tightly coupled despite having clean project structures: teams tend to define physical boundaries (projects,... og:url: https://daily.dev/posts/modular-monolith-boundaries-done-wrong-4jnemg3nw og:image: https://api.daily.dev/og/posts/4JNEMG3Nw.png og:image:alt: Modular Monolith Boundaries Done Wrong og:image:width: 1200 og:image:height: 630 og:locale: en --- > ## Documentation Index > Fetch the complete documentation index at: https://daily.dev/llms.txt > Use this file to discover all available pages before exploring further. # Modular Monolith Boundaries Done Wrong **[CodeOpinion](https://daily.dev/sources/codeopinion)** · [@codeopinion](https://daily.dev/codeopinion) · 10 min read · 1 upvotes · 1 comments ## Summary Explains why modular monoliths often remain tightly coupled despite having clean project structures: teams tend to define physical boundaries (projects, databases, deployables) rather than logical boundaries based on ownership. Logical boundaries are about who owns the rules, lifecycle, and meaning of a concept, not where code lives. Uses examples like 'vehicle' meaning different things in compliance vs. dispatch, and 'employee' meaning different things in HR vs. IT, to show that sharing one model across modules recreates coupling. Argues logical boundaries are not physical boundaries, and database or deployment separation does not by itself define or enforce ownership. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Community discussion Top comments from developers on daily.dev. **@swarnasharmin** · 0 upvotes > Spot on. Separate folders mean nothing if different domains share the exact same models. True boundaries are about ownership, not file paths. ## Similar posts on daily.dev - [The Modular Monolith Boundary I Couldn't Take Back](https://daily.dev/posts/the-modular-monolith-boundary-i-couldn-t-take-back-6vxxy5za5) · Milan Jovanović · 42 upvotes · 1 comments - [Modular Monolith and Microservices: Modularity is what truly matters](https://daily.dev/posts/modular-monolith-and-microservices-modularity-is-what-truly-matters-alztxj5cq) · Hacker News · 28 upvotes · 1 comments --- Tags: [#career](https://daily.dev/tags/career), [#architecture](https://daily.dev/tags/architecture), [#microservices](https://daily.dev/tags/microservices), [#domain-driven-design](https://daily.dev/tags/domain-driven-design) [View this post on daily.dev](https://daily.dev/posts/modular-monolith-boundaries-done-wrong-4jnemg3nw) ```json {"@context":"https://schema.org","@graph":[{"@type":"Organization","@id":"https://daily.dev/#organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180},"sameAs":["https://twitter.com/dailydotdev","https://github.com/dailydotdev","https://www.linkedin.com/company/daily-dev-ltd"]},{"@type":"WebSite","@id":"https://daily.dev/#website","url":"https://daily.dev","name":"daily.dev","publisher":{"@id":"https://daily.dev/#organization"},"potentialAction":{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https://daily.dev/search?q={search_term_string}"},"query-input":"required name=search_term_string"}}]} {"@context":"https://schema.org","@type":"TechArticle","headline":"Modular Monolith Boundaries Done Wrong","url":"https://daily.dev/posts/modular-monolith-boundaries-done-wrong-4jnemg3nw","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/modular-monolith-boundaries-done-wrong-4jnemg3nw"},"datePublished":"2026-10-04T13:08:04.478Z","dateModified":"2026-10-05T10:00:18.362Z","description":"Explains why modular monoliths often remain tightly coupled despite having clean project structures: teams tend to define physical boundaries (projects,...","image":"https://media.daily.dev/image/upload/f_auto,q_auto/v1/posts/ca28d3696a882bbb2e6d5c4964a717a7?_a=AQAEuop","thumbnailUrl":"https://media.daily.dev/image/upload/f_auto,q_auto/v1/posts/ca28d3696a882bbb2e6d5c4964a717a7?_a=AQAEuop","isAccessibleForFree":true,"articleSection":"CodeOpinion","inLanguage":"en","publisher":{"@type":"Organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180}},"author":{"@type":"Person","name":"Derek Comartin","url":"https://daily.dev/codeopinion","image":"https://lh3.googleusercontent.com/a-/AOh14GgoQapb7NmLN1TZ6L-UCxkRpDZ4H7LKwud1DUZCTSI=s100","interactionStatistic":{"@type":"InteractionCounter","interactionType":{"@type":"EndorseAction"},"userInteractionCount":950}},"commentCount":1,"discussionUrl":"https://daily.dev/posts/modular-monolith-boundaries-done-wrong-4jnemg3nw","interactionStatistic":[{"@type":"InteractionCounter","interactionType":{"@type":"LikeAction"},"userInteractionCount":1},{"@type":"InteractionCounter","interactionType":{"@type":"CommentAction"},"userInteractionCount":1}],"keywords":"career,architecture,microservices,domain-driven-design","timeRequired":"PT10M"} {"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https://daily.dev"},{"@type":"ListItem","position":2,"name":"CodeOpinion","item":"https://daily.dev/sources/codeopinion"},{"@type":"ListItem","position":3,"name":"Modular Monolith Boundaries Done Wrong"}]} {"@context":"https://schema.org","@type":"WebPage","@id":"https://daily.dev/posts/modular-monolith-boundaries-done-wrong-4jnemg3nw","comment":[{"@type":"Comment","text":"Spot on. Separate folders mean nothing if different domains share the exact same models. True boundaries are about ownership, not file paths.","datePublished":"2026-10-05T18:43:42.844Z","url":"https://daily.dev/posts/4JNEMG3Nw#c-IUb6QO8I8","author":{"@type":"Person","name":"Swarna Sharmin","url":"https://daily.dev/swarnasharmin","image":"https://media.daily.dev/image/upload/s--joHEq_jD--/f_auto/v1791022797/avatars/avatar_ZL6bebyCVkszL2cr0g8ab?_a=BAMAMicg0"}}]} ```