--- title: Python 3.15’s Ultra-Low Overhead Interpreter Profiling Mode description: CPython 3.15 introduces a novel ultra-low overhead interpreter profiling mode to support JIT trace recording. Instead of duplicating interpreter logic or using... canonical: https://daily.dev/posts/python-3-15-s-ultra-low-overhead-interpreter-profiling-mode-raknysu9x twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: Python 3.15’s Ultra-Low Overhead Interpreter Profiling Mode | daily.dev og:description: CPython 3.15 introduces a novel ultra-low overhead interpreter profiling mode to support JIT trace recording. Instead of duplicating interpreter logic or using... og:url: https://daily.dev/posts/python-3-15-s-ultra-low-overhead-interpreter-profiling-mode-raknysu9x og:image: https://api.daily.dev/og/posts/raKNYsu9x.png og:image:alt: Python 3.15’s Ultra-Low Overhead Interpreter Profiling Mode 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. # Python 3.15’s Ultra-Low Overhead Interpreter Profiling Mode **[Hacker News](https://daily.dev/sources/hn)** · 7 min read · 0 upvotes · 0 comments ## Summary CPython 3.15 introduces a novel ultra-low overhead interpreter profiling mode to support JIT trace recording. Instead of duplicating interpreter logic or using conditional branches, it uses two dispatch tables — one for normal execution and one for profiling — where all profiling-mode opcodes fan into a single recording instruction before dispatching back to the normal interpreter. This approach achieves only ~4.5x overhead during profiling compared to 900-1000x in systems like PyPy. The technique is broadly applicable beyond JIT trace recording, including runtime type profiling and low-overhead interpreter instrumentation. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Similar posts on daily.dev - [Python 3.15 Preview: Upgraded JIT Compiler – Real Python](https://daily.dev/posts/python-3-15-preview-upgraded-jit-compiler-real-python-ih00g8tar) · Real Python · 0 upvotes · 0 comments - [Python 3.15’s JIT is now back on track](https://daily.dev/posts/python-3-15-s-jit-is-now-back-on-track-mhtoosety) · Hacker News · 2 upvotes · 0 comments - [Python 3.14 and its New JIT Compiler](https://daily.dev/posts/python-3-14-and-its-new-jit-compiler-sx1mbtt4z) · Towards Data Science · 1 upvotes · 0 comments - [A Plan for 5-10%\* Faster Free-Threaded JIT by Python 3.16](https://daily.dev/posts/a-plan-for-5-10-faster-free-threaded-jit-by-python-3-16-rfcbbt4dy) · Lobsters · 0 upvotes · 0 comments - [Get started with Python’s new native JIT](https://daily.dev/posts/get-started-with-python-s-new-native-jit-a6z6eivtt) · InfoWorld · 0 upvotes · 0 comments --- Tags: [#python](https://daily.dev/tags/python), [#cpython](https://daily.dev/tags/cpython) [View this post on daily.dev](https://daily.dev/posts/python-3-15-s-ultra-low-overhead-interpreter-profiling-mode-raknysu9x) ```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":"Python 3.15’s Ultra-Low Overhead Interpreter Profiling Mode","url":"https://daily.dev/posts/python-3-15-s-ultra-low-overhead-interpreter-profiling-mode-raknysu9x","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/python-3-15-s-ultra-low-overhead-interpreter-profiling-mode-raknysu9x"},"datePublished":"2026-07-21T15:04:05.622Z","dateModified":"2026-07-21T15:04:28.474Z","description":"CPython 3.15 introduces a novel ultra-low overhead interpreter profiling mode to support JIT trace recording. 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