--- title: We Needed Better Charts in Flutter, So Naturally, We... description: A developer journey detailing how building a data-analysis tool for physiological metrics (power, heart rate, lactate, etc.) led to creating Braven Charts — a... canonical: https://daily.dev/posts/we-needed-better-charts-in-flutter-so-naturally-we-built-a-rendering-engine-uetgdlifo twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: We Needed Better Charts in Flutter, So Naturally, We Built a Rendering Engine | daily.dev og:description: A developer journey detailing how building a data-analysis tool for physiological metrics (power, heart rate, lactate, etc.) led to creating Braven Charts — a... og:url: https://daily.dev/posts/we-needed-better-charts-in-flutter-so-naturally-we-built-a-rendering-engine-uetgdlifo og:image: https://api.daily.dev/og/posts/uETGDLIFo.png og:image:alt: We Needed Better Charts in Flutter, So Naturally, We Built a Rendering Engine 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. # We Needed Better Charts in Flutter, So Naturally, We Built a Rendering Engine **[Medium](https://daily.dev/sources/medium_js)** · 21 min read · 0 upvotes · 0 comments ## Summary A developer journey detailing how building a data-analysis tool for physiological metrics (power, heart rate, lactate, etc.) led to creating Braven Charts — a custom Flutter charting library built on a native RenderBox rather than existing packages. The post covers the full evolution: from an over-engineered v1 using CustomPainter, to a proper rendering engine with three formalized coordinate systems, multi-axis normalization, a layered paint architecture for performance, a state-machine interaction model, and a streaming API bypassing the widget tree. Key engineering lessons include separating stable from dynamic paint layers (reducing hover frame cost from ~17ms to ~0.1ms), using a QuadTree for spatial hit testing, keeping hot state out of setState(), and treating annotations as domain data rather than decoration. The package is open source on pub.dev and GitHub. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Similar posts on daily.dev - [Building Native Trading Charts for Groww Android](https://daily.dev/posts/building-native-trading-charts-for-groww-android-lfqhukdmh) · Groww Engineering · 1 upvotes · 0 comments - [You Don’t Need a Screen: Exploring Flutter’s Headless Render Pipeline](https://daily.dev/posts/you-don-t-need-a-screen-exploring-flutter-s-headless-render-pipeline-2w7djtz5o) · ITNEXT · 2 upvotes · 0 comments - [TanStack Charts 1.0](https://daily.dev/posts/tanstack-charts-1-0-rfrxdv6yp) · TanStack · 160 upvotes · 11 comments - [Medium](https://daily.dev/posts/medium-sm7b9uyve) · Medium · 0 upvotes · 0 comments --- Tags: [#performance](https://daily.dev/tags/performance), [#flutter](https://daily.dev/tags/flutter), [#data-visualization](https://daily.dev/tags/data-visualization), [#dart](https://daily.dev/tags/dart) [View this post on daily.dev](https://daily.dev/posts/we-needed-better-charts-in-flutter-so-naturally-we-built-a-rendering-engine-uetgdlifo) ```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":"We Needed Better Charts in Flutter, So Naturally, We Built a Rendering Engine","url":"https://daily.dev/posts/we-needed-better-charts-in-flutter-so-naturally-we-built-a-rendering-engine-uetgdlifo","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/we-needed-better-charts-in-flutter-so-naturally-we-built-a-rendering-engine-uetgdlifo"},"datePublished":"2026-07-22T15:10:00.893Z","dateModified":"2026-07-22T15:13:05.584Z","description":"A developer journey detailing how building a data-analysis tool for physiological metrics (power, heart rate, lactate, etc.) led to creating Braven Charts — a...","image":"https://media.daily.dev/image/upload/s--P4t4XyoV--/f_auto/v1722860399/public/Placeholder%2001","thumbnailUrl":"https://media.daily.dev/image/upload/s--P4t4XyoV--/f_auto/v1722860399/public/Placeholder%2001","isAccessibleForFree":true,"articleSection":"Medium","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":"Organization","name":"Medium","logo":"https://media.daily.dev/image/upload/t_logo,f_auto/v1/logos/medium","url":"https://daily.dev/sources/medium_js"},"commentCount":0,"discussionUrl":"https://daily.dev/posts/we-needed-better-charts-in-flutter-so-naturally-we-built-a-rendering-engine-uetgdlifo","interactionStatistic":[{"@type":"InteractionCounter","interactionType":{"@type":"LikeAction"},"userInteractionCount":0},{"@type":"InteractionCounter","interactionType":{"@type":"CommentAction"},"userInteractionCount":0}],"keywords":"performance,flutter,data-visualization,dart","timeRequired":"PT21M"} {"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https://daily.dev"},{"@type":"ListItem","position":2,"name":"Medium","item":"https://daily.dev/sources/medium_js"},{"@type":"ListItem","position":3,"name":"We Needed Better Charts in Flutter, So Naturally, We Built a Rendering Engine"}]} ```