--- title: Breaking changes – not great, not terrible - Jan Musílek description: [EuroPython 2026 - S3A on 2026-07-17] 🎤 *Breaking changes – not great, not terrible by Jan Musílek* 🔗... canonical: https://daily.dev/posts/breaking-changes-not-great-not-terrible---jan-mus-lek-8cbosbnou twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: Breaking changes – not great, not terrible - Jan Musílek | daily.dev og:description: [EuroPython 2026 - S3A on 2026-07-17] 🎤 *Breaking changes – not great, not terrible by Jan Musílek* 🔗... og:url: https://daily.dev/posts/breaking-changes-not-great-not-terrible---jan-mus-lek-8cbosbnou og:image: https://api.daily.dev/og/posts/8cBOsbnou.png og:image:alt: Breaking changes – not great, not terrible - Jan Musílek 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. # Breaking changes – not great, not terrible - Jan Musílek **[EuroPython Conference](https://daily.dev/sources/europython)** · 28 min read · 0 upvotes · 0 comments ## Summary [EuroPython 2026 - S3A on 2026-07-17] 🎤 *Breaking changes – not great, not terrible by Jan Musílek* 🔗 https://ep2026.europython.eu/session/breaking-changes-not-great-not-terrible 📝 Abstract: Do you maintain a Python library, REST API or any other user-facing interface? Breaking changes are frowned upon, but from a a certain project size, they become unavoidable. How do you make the breaking changes manageable? How should you version your package / API? Should you put an upper bound on your dependencies? We'll discuss deprecation, forward and backward compatibility, upgrade strategies and more, illustrated on real-world examples. Our main focus will be on API changes of Python libraries, but the principles are widely applicable. --- This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License: https://creativecommons.org/licenses/by-nc-sa/4.0/ ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: --- Tags: [#python](https://daily.dev/tags/python), [#conference](https://daily.dev/tags/conference) [View this post on daily.dev](https://daily.dev/posts/breaking-changes-not-great-not-terrible---jan-mus-lek-8cbosbnou) ```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":"Breaking changes – not great, not terrible - Jan Musílek","url":"https://daily.dev/posts/breaking-changes-not-great-not-terrible---jan-mus-lek-8cbosbnou","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/breaking-changes-not-great-not-terrible---jan-mus-lek-8cbosbnou"},"datePublished":"2026-08-19T10:14:18.565Z","dateModified":"2026-08-19T12:01:56.470Z","description":"[EuroPython 2026 - S3A on 2026-07-17]\n🎤 *Breaking changes – not great, not terrible by Jan Musílek* \n🔗...","image":"https://i.ytimg.com/vi/tny5Ac4VlIo/sddefault.jpg","thumbnailUrl":"https://i.ytimg.com/vi/tny5Ac4VlIo/sddefault.jpg","isAccessibleForFree":true,"articleSection":"EuroPython Conference","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":"EuroPython Conference","logo":"https://media.daily.dev/image/upload/s--qu8RO-lH--/f_auto,q_auto/v1777800764/logos/europython?_a=BAMAMiWQ0","url":"https://daily.dev/sources/europython"},"commentCount":0,"discussionUrl":"https://daily.dev/posts/breaking-changes-not-great-not-terrible---jan-mus-lek-8cbosbnou","interactionStatistic":[{"@type":"InteractionCounter","interactionType":{"@type":"LikeAction"},"userInteractionCount":0},{"@type":"InteractionCounter","interactionType":{"@type":"CommentAction"},"userInteractionCount":0}],"keywords":"python,conference","timeRequired":"PT28M","video":{"@type":"VideoObject","name":"Breaking changes – not great, not terrible - Jan Musílek","description":"[EuroPython 2026 - S3A on 2026-07-17]\n🎤 *Breaking changes – not great, not terrible by Jan Musílek* \n🔗...","thumbnailUrl":"https://i.ytimg.com/vi/tny5Ac4VlIo/sddefault.jpg","uploadDate":"2026-08-19T10:14:18.565Z","duration":"PT28M","url":"https://api.daily.dev/r/8cBOsbnou","embedUrl":"https://www.youtube.com/embed/tny5Ac4VlIo"}} {"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https://daily.dev"},{"@type":"ListItem","position":2,"name":"EuroPython Conference","item":"https://daily.dev/sources/europython"},{"@type":"ListItem","position":3,"name":"Breaking changes – not great, not terrible - Jan Musílek"}]} ```