--- title: Building Custom Evaluators for AI Applications: The... description: Generic metrics like accuracy and relevance fail to capture real-world AI product requirements such as compliance, brand tone, and safety boundaries. Custom... canonical: https://daily.dev/posts/building-custom-evaluators-for-ai-applications-the-missing-layer-tk4kajddh twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: Building Custom Evaluators for AI Applications: The Missing Layer | daily.dev og:description: Generic metrics like accuracy and relevance fail to capture real-world AI product requirements such as compliance, brand tone, and safety boundaries. Custom... og:url: https://daily.dev/posts/building-custom-evaluators-for-ai-applications-the-missing-layer-tk4kajddh og:image: https://api.daily.dev/og/posts/tk4kajddh.png og:image:alt: Building Custom Evaluators for AI Applications: The Missing Layer og:image:width: 1200 og:image:height: 630 og:locale: en --- [](https://daily.dev/kuldeeppaul27)[Kuldeep Paul @kuldeeppaul27 • Jan 1690](https://daily.dev/kuldeeppaul27) # Building Custom Evaluators for AI Applications: The Missing Layer [](https://media.daily.dev/image/upload/s--Mcw9HAcn--/f%5Fauto/v1768580320/posts/tk4kajddh?%5Fa=BAMAMiiu0) Comment Bookmark Copy Share your thoughts Post Share this post [](https://daily.dev/kuldeeppaul27) [Kuldeep Paul](https://daily.dev/kuldeeppaul27) [@kuldeeppaul27](https://daily.dev/kuldeeppaul27) Joined May 13\. 2025 90 #### Would you recommend this post? Copy link Slack WhatsApp Facebook X New Squad Copy linkShare with your friends ```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":"DiscussionForumPosting","mainEntityOfPage":"https://daily.dev/posts/building-custom-evaluators-for-ai-applications-the-missing-layer-tk4kajddh","headline":"Building Custom Evaluators for AI Applications: The Missing Layer","text":"Generic metrics like accuracy and relevance fail to capture real-world AI product requirements such as compliance, brand tone, and safety boundaries. Custom evaluators encode business logic and product expectations into measurable checks that run automatically at scale. Four key patterns emerge: LLM-based evaluators for subjective criteria, programmatic evaluators for deterministic rules, API-based evaluators for external compliance systems, and human evaluators for high-risk scenarios. Evaluation should be continuous, with production failures feeding back into test cases and prompt improvements rather than serving as a one-time quality gate.","url":"https://daily.dev/posts/building-custom-evaluators-for-ai-applications-the-missing-layer-tk4kajddh","datePublished":"2026-01-16T16:18:39.650Z","dateModified":"2026-01-29T07:26:13.675Z","author":{"@type":"Person","name":"Kuldeep Paul","url":"https://daily.dev/kuldeeppaul27","image":"https://lh3.googleusercontent.com/a/ACg8ocJFEPn-pqwhXxqwm9ubzIjsQsO1yUD81jEzHR85et9mCjdyPI0=s96-c","interactionStatistic":{"@type":"InteractionCounter","interactionType":{"@type":"EndorseAction"},"userInteractionCount":90}},"image":"https://media.daily.dev/image/upload/s--Mcw9HAcn--/f_auto/v1768580320/posts/tk4kajddh?_a=BAMAMiiu0","interactionStatistic":[{"@type":"InteractionCounter","interactionType":{"@type":"LikeAction"},"userInteractionCount":0},{"@type":"InteractionCounter","interactionType":{"@type":"CommentAction"},"userInteractionCount":0}],"isPartOf":{"@type":"WebPage","url":"https://daily.dev/sources/zu5ifohhtulx9mcg2ztub","name":"Kuldeep Paul"}} {"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https://daily.dev"},{"@type":"ListItem","position":2,"name":"Kuldeep Paul","item":"https://daily.dev/sources/zu5ifohhtulx9mcg2ztub"},{"@type":"ListItem","position":3,"name":"Building Custom Evaluators for AI Applications: The Missing Layer"}]} ```