# Inside SubcomposeLayout: Jetpack Compose's Most Misunderstood API

DevFeed: [Inside SubcomposeLayout: Jetpack Compose's Most Misunderstood API](<https://devfeed.tech/articles/inside-subcomposelayout-jetpack-compose-s-most-misunderstood-api-25730.md>)

Original publisher: [Read original article](<https://blog.shreyaspatil.dev/inside-subcomposelayout-jetpack-composes-most-misunderstood-api/>)

Author: Shreyas Patil

Published: 2026-07-10T12:05:00Z

Content type: article

Language: en

Sources: [Shreyas Patil's Blog](<https://devfeed.tech/sources/shreyas-patil-s-blog.md>)

Topics: [Jetpack Compose](<https://devfeed.tech/topics/jetpack-compose.md>), [Compose](<https://devfeed.tech/topics/compose.md>), [ui](<https://devfeed.tech/topics/ui.md>)

Tags: [android](<https://devfeed.tech/tags/android.md>), [android-app-development](<https://devfeed.tech/tags/android-app-development.md>), [compose](<https://devfeed.tech/tags/compose.md>), [declarative](<https://devfeed.tech/tags/declarative.md>), [deep-dive](<https://devfeed.tech/tags/deep-dive.md>), [internals](<https://devfeed.tech/tags/internals.md>), [jetpack-compose](<https://devfeed.tech/tags/jetpack-compose.md>), [kotlin](<https://devfeed.tech/tags/kotlin.md>), [learn](<https://devfeed.tech/tags/learn.md>), [performance](<https://devfeed.tech/tags/performance.md>), [performance-optimization](<https://devfeed.tech/tags/performance-optimization.md>), [ui](<https://devfeed.tech/tags/ui.md>), [uiux](<https://devfeed.tech/tags/uiux.md>)

## AI overview

A deep dive into Jetpack Compose's SubcomposeLayout, explaining how it performs composition during measurement or placement, stalls the normal layout pipeline, and can create performance costs. The article also outlines when standard custom layouts or SubcomposeLayout are appropriate.

## Source excerpt

A deep dive into the internals of SubcomposeLayout in Jetpack Compose. Learn how subcomposition actually works, why it breaks the phase rules, and the real node-thrashing cost it carries.