# Faster Starts, Less JavaScript Overhead

DevFeed: [Faster Starts, Less JavaScript Overhead](<https://devfeed.tech/articles/faster-starts-less-javascript-overhead-19531.md>)

Original publisher: [Read original article](<https://www.codenameone.com/blog/startup-cost-before-first-paint/>)

Author: Shai Almog

Published: 2026-09-14T00:00:00Z

Content type: article

Language: en

Sources: [CodeName One](<https://devfeed.tech/sources/codename-one.md>)

Topics: [JavaScript](<https://devfeed.tech/topics/javascript.md>), [Compiler](<https://devfeed.tech/topics/compiler.md>), [Instrumentation](<https://devfeed.tech/topics/instrumentation.md>)

Tags: [benchmarks](<https://devfeed.tech/tags/benchmarks.md>), [compiler](<https://devfeed.tech/tags/compiler.md>), [instrumentation](<https://devfeed.tech/tags/instrumentation.md>), [javascript](<https://devfeed.tech/tags/javascript.md>), [profiling](<https://devfeed.tech/tags/profiling.md>)

## AI overview

The article describes startup-performance work in Codename One. It identifies launch delays caused by repeated screen-scale queries, theme scans, unnecessary synchronous dispatches, premature GC-park handshakes, and JavaScript suspension preparation. The fixes publish screen state atomically, avoid waiting when operations can proceed immediately, index theme keys, and improve instrumentation so profiling reveals hidden stalls.

## Source excerpt

Codename One removes native startup waits, repeated style scans, and unnecessary JavaScript suspension. Profiles and compiler benchmarks expose costs that bundle size and frame rates miss.