--- title: The User Who Couldn’t See Their Own Comment | daily.dev description: A real-world incident where a user couldn't see their own comment after posting reveals the hidden cost of async database replication. When reads are routed to... canonical: https://daily.dev/posts/the-user-who-couldn-t-see-their-own-comment-4ilz7cpdq twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: The User Who Couldn’t See Their Own Comment | daily.dev og:description: A real-world incident where a user couldn't see their own comment after posting reveals the hidden cost of async database replication. When reads are routed to... og:url: https://daily.dev/posts/the-user-who-couldn-t-see-their-own-comment-4ilz7cpdq og:image: https://api.daily.dev/og/posts/4ilZ7cPdq.png og:image:alt: The User Who Couldn’t See Their Own Comment 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. # The User Who Couldn’t See Their Own Comment **[Medium](https://daily.dev/sources/medium_js)** · 5 min read · 0 upvotes · 0 comments ## Summary A real-world incident where a user couldn't see their own comment after posting reveals the hidden cost of async database replication. When reads are routed to a replica lagging 1.4 seconds behind the primary, the user's freshly written comment hasn't propagated yet — causing confusion and duplicate posts. The post explains async vs synchronous replication trade-offs, introduces read-your-writes consistency as the targeted fix (author-pinning to primary, session tokens, or optimistic UI), and covers failover risks including non-zero RPO and split-brain scenarios. Framed as both a war story and a structured interview prep guide. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: --- Tags: [#career](https://daily.dev/tags/career), [#database](https://daily.dev/tags/database), [#distributed-systems](https://daily.dev/tags/distributed-systems) [View this post on daily.dev](https://daily.dev/posts/the-user-who-couldn-t-see-their-own-comment-4ilz7cpdq) ```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":"The User Who Couldn’t See Their Own Comment","url":"https://daily.dev/posts/the-user-who-couldn-t-see-their-own-comment-4ilz7cpdq","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/the-user-who-couldn-t-see-their-own-comment-4ilz7cpdq"},"datePublished":"2026-07-24T04:45:05.201Z","dateModified":"2026-07-24T04:46:32.800Z","description":"A real-world incident where a user couldn't see their own comment after posting reveals the hidden cost of async database replication. When reads are routed to...","image":"https://media.daily.dev/image/upload/f_auto,q_auto/v1/posts/e150bdfe79bf0cdb63590598b68e2bf2?_a=AQAEuop","thumbnailUrl":"https://media.daily.dev/image/upload/f_auto,q_auto/v1/posts/e150bdfe79bf0cdb63590598b68e2bf2?_a=AQAEuop","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/the-user-who-couldn-t-see-their-own-comment-4ilz7cpdq","interactionStatistic":[{"@type":"InteractionCounter","interactionType":{"@type":"LikeAction"},"userInteractionCount":0},{"@type":"InteractionCounter","interactionType":{"@type":"CommentAction"},"userInteractionCount":0}],"keywords":"career,database,distributed-systems","timeRequired":"PT5M"} {"@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":"The User Who Couldn’t See Their Own Comment"}]} ```