--- title: adam bien's blog | daily.dev description: BCE (Boundary-Control-Entity) architecture defines strict dependency rules within and between business components. Inside a component, dependencies flow... canonical: https://daily.dev/posts/adam-bien-s-blog-j5vai0nvm twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: adam bien's blog | daily.dev og:description: BCE (Boundary-Control-Entity) architecture defines strict dependency rules within and between business components. Inside a component, dependencies flow... og:url: https://daily.dev/posts/adam-bien-s-blog-j5vai0nvm og:image: https://api.daily.dev/og/posts/J5vaI0nvM.png og:image:alt: adam bien's blog 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. # adam bien's blog **[Adam Bien](https://daily.dev/sources/adam-bien)** · 2 min read · 0 upvotes · 0 comments ## Summary BCE (Boundary-Control-Entity) architecture defines strict dependency rules within and between business components. Inside a component, dependencies flow downward: boundary to control to entity, or boundary to entity directly. Entities never depend upward — they emit events instead. Between components, control-to-control and entity-to-entity calls are allowed and direct, while boundary-to-boundary calls should be avoided. A useful heuristic: if a component communicates more with neighbors than with itself, it was split incorrectly. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Questions this post answers ### In the BCE architecture pattern, what dependencies are allowed inside a business component? Dependencies must point downward: boundary can call control, and control calls entity. Boundary can also call entity directly for simple use cases, skipping control. Entities must never call control or boundary directly; instead, an entity emits an event that any layer of any component can process, keeping the entity unaware of who receives it. _Developers structuring layered components can compare BCE dependency rules against their own designs on daily.dev._ ### Is it okay for one business component's control layer to call another component's control layer directly in a BCE design? Yes, control-to-control calls between business components are allowed and can be made directly without requiring interfaces in between. In Quarkus and MicroProfile applications, the control is simply injected. Boundary-to-boundary calls between components should be avoided, though acceptable temporarily early in a project before a control layer takes over. _Teams deciding how components should communicate can track pattern guidance like this on daily.dev._ ### How do I know if I split a business component in the wrong place? Count the internal links versus the links to neighboring components: if a component communicates less with itself than with its neighbors, it was cut in the wrong place. This heuristic helps validate whether component boundaries in a BCE (Boundary-Control-Entity) design are drawn correctly. _Anyone refining component boundaries can weigh heuristics like this while reviewing architecture on daily.dev._ ## Similar posts on daily.dev - [From Java EE to Quarkus and LLMs: Adam Bien’s Playbook for Boring, Future‑Proof Systems](https://daily.dev/posts/from-java-ee-to-quarkus-and-llms-adam-bien-s-playbook-for-boring-future-proof-systems-0metu7xbn) · InfoQ · 16 upvotes · 0 comments - [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 - [No, Your Domains and Bounded Contexts Don’t Map 1 on 1](https://daily.dev/posts/no-your-domains-and-bounded-contexts-don-t-map-1-on-1-rh3kxenlx) · Mathias Verraes · 0 upvotes · 0 comments --- Tags: [#architecture](https://daily.dev/tags/architecture), [#quarkus](https://daily.dev/tags/quarkus), [#domain-driven-design](https://daily.dev/tags/domain-driven-design) [View this post on daily.dev](https://daily.dev/posts/adam-bien-s-blog-j5vai0nvm) ```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":"adam bien's blog","url":"https://daily.dev/posts/adam-bien-s-blog-j5vai0nvm","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/adam-bien-s-blog-j5vai0nvm"},"datePublished":"2026-08-11T15:24:22.010Z","dateModified":"2026-09-14T06:42:26.364Z","description":"BCE (Boundary-Control-Entity) architecture defines strict dependency rules within and between business components. 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