--- title: How Meta Built Forum With AI-Native Engineering | daily.dev description: Meta engineers describe how they built Forum, a standalone app for Facebook Groups, using an AI-native development model they call 'human-on-the-loop,' where... canonical: https://daily.dev/posts/how-meta-built-forum-with-ai-native-engineering-nt4rhnnet twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: How Meta Built Forum With AI-Native Engineering | daily.dev og:description: Meta engineers describe how they built Forum, a standalone app for Facebook Groups, using an AI-native development model they call 'human-on-the-loop,' where... og:url: https://daily.dev/posts/how-meta-built-forum-with-ai-native-engineering-nt4rhnnet og:image: https://api.daily.dev/og/posts/nt4RhnnET.png og:image:alt: How Meta Built Forum With AI-Native Engineering 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. # How Meta Built Forum With AI-Native Engineering **[Facebook Engineering ](https://daily.dev/sources/facebook_code)** · 9 min read · 1 upvotes · 0 comments ## Summary Meta engineers describe how they built Forum, a standalone app for Facebook Groups, using an AI-native development model they call 'human-on-the-loop,' where agents plan, implement, build, test, and verify code while engineers set goals and approve outcomes. Key practices included treating automated verification (builds, tests, UI matching) as a gate rather than compilation alone, giving agents direct tools to inspect app state instead of relying on descriptions, using a separate sandbox build flavor to isolate prototype code from production, and deploying navigation agents for continuous stress testing that caught a memory regression before launch. The team reports reaching feature parity with Facebook Groups in eight weeks and roughly halving memory use and page faults through autonomous stress-testing. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Questions this post answers ### What is the difference between human-in-the-loop and human-on-the-loop AI development? Human-in-the-loop means the engineer drives every step while AI assists within it, such as autocompleting functions or suggesting fixes, advancing at the engineer's pace. Human-on-the-loop means an agent runs the full plan-implement-build-test-correct cycle itself, while the engineer sets the goal, monitors the run, intervenes when it drifts, and approves the final result. _Teams weighing how much autonomy to hand AI agents can track emerging engineering playbooks like this on daily.dev._ ### How long did it take Meta to build the Forum app to feature parity with Facebook Groups? Meta's small engineering team reached core feature parity with Facebook Groups in eight weeks, using an agentic AI development approach where AI handled much of the routine implementation so engineers could focus on architecture, product decisions, and quality. The build also used a separate sandbox build flavor to keep prototype code out of production entirely. _Developers benchmarking realistic AI-accelerated build timelines can follow similar case studies on daily.dev._ ### How did Meta catch the memory issue in the Forum app before launch? An autonomous stress-testing loop ran repeatable scenarios mimicking real user behavior, including aggressive scrolling, random group browsing, rapid navigation, and repeated media loading, across builds. The consistent crash, memory growth, and page fault signals let an AI agent triage anomalies, isolate a repro, propose a fix, and verify it during development, roughly halving memory use and page faults before users were affected. _Engineers building automated regression and stress-testing pipelines can find similar practices on daily.dev._ ## Similar posts on daily.dev - [Forum is Meta’s new Facebook Groups app, and it looks a lot like Reddit](https://daily.dev/posts/forum-is-meta-s-new-facebook-groups-app-and-it-looks-a-lot-like-reddit-4njbiy8cv) · The Next Web · 0 upvotes · 0 comments - [Meta quietly launches a new Reddit-like app called Forum](https://daily.dev/posts/meta-quietly-launches-a-new-reddit-like-app-called-forum-tggbm5ehj) · TechCrunch · 0 upvotes · 0 comments - [Meta says AI is making it easier to build new apps — and more are coming](https://daily.dev/posts/meta-says-ai-is-making-it-easier-to-build-new-apps-and-more-are-coming-gmtrvfwxg) · TechCrunch · 0 upvotes · 0 comments - [Facebook now has an AI search engine that pulls answers from your Group posts and Reels](https://daily.dev/posts/facebook-now-has-an-ai-search-engine-that-pulls-answers-from-your-group-posts-and-reels-orsdve7bz) · The Next Web · 0 upvotes · 0 comments --- Tags: [#testing](https://daily.dev/tags/testing), [#mobile](https://daily.dev/tags/mobile), [#ai-coding](https://daily.dev/tags/ai-coding), [#agentic-ai](https://daily.dev/tags/agentic-ai) [View this post on daily.dev](https://daily.dev/posts/how-meta-built-forum-with-ai-native-engineering-nt4rhnnet) ```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":"How Meta Built Forum With AI-Native Engineering","url":"https://daily.dev/posts/how-meta-built-forum-with-ai-native-engineering-nt4rhnnet","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/how-meta-built-forum-with-ai-native-engineering-nt4rhnnet"},"datePublished":"2026-10-15T19:03:25.557Z","dateModified":"2026-10-15T19:11:15.306Z","description":"Meta engineers describe how they built Forum, a standalone app for Facebook Groups, using an AI-native development model they call 'human-on-the-loop,' where...","image":"https://media.daily.dev/image/upload/f_auto,q_auto/v1/posts/c74240a31f6611955424c123a00fe528?_a=AQAEuop","thumbnailUrl":"https://media.daily.dev/image/upload/f_auto,q_auto/v1/posts/c74240a31f6611955424c123a00fe528?_a=AQAEuop","isAccessibleForFree":true,"articleSection":"Facebook Engineering\n","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":"Facebook Engineering\n","logo":"https://media.daily.dev/image/upload/t_logo,f_auto/v1/logos/facebook","url":"https://daily.dev/sources/facebook_code"},"commentCount":0,"discussionUrl":"https://daily.dev/posts/how-meta-built-forum-with-ai-native-engineering-nt4rhnnet","interactionStatistic":[{"@type":"InteractionCounter","interactionType":{"@type":"LikeAction"},"userInteractionCount":1},{"@type":"InteractionCounter","interactionType":{"@type":"CommentAction"},"userInteractionCount":0}],"keywords":"testing,mobile,ai-coding,agentic-ai","timeRequired":"PT9M"} {"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https://daily.dev"},{"@type":"ListItem","position":2,"name":"Facebook Engineering\n","item":"https://daily.dev/sources/facebook_code"},{"@type":"ListItem","position":3,"name":"How Meta Built Forum With AI-Native Engineering"}]} {"@context":"https://schema.org","@type":"FAQPage","@id":"https://daily.dev/posts/how-meta-built-forum-with-ai-native-engineering-nt4rhnnet#faq","mainEntity":[{"@type":"Question","name":"What is the difference between human-in-the-loop and human-on-the-loop AI development?","acceptedAnswer":{"@type":"Answer","text":"Human-in-the-loop means the engineer drives every step while AI assists within it, such as autocompleting functions or suggesting fixes, advancing at the engineer's pace. 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