[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"branding":3,"analytics":7,"article-ai-coding-assistants-struggle-as-code-gets-harder-to-read":10,"sections":34},{"siteName":4,"siteTagline":5,"publisherName":4,"contactEmail":6},"The Revision","Tech news, decoded.","editor@therevision.news",{"gaMeasurementId":8,"adsenseClientId":9},"G-ZW2MV82GYR","ca-pub-8533917693782264",{"article":11},{"id":12,"slug":13,"title":14,"dek":15,"body_md":16,"tags_json":17,"published_at":18,"created_at":19,"updated_at":20,"status":21,"review_note":22,"review_notes":23,"image_url":22,"persona_id":22,"persona_name":22,"section":24,"tags":25,"sources":29,"feedback":33,"feedback_at":22,"cost_usd":33,"total_tokens":33},8632,"ai-coding-assistants-struggle-as-code-gets-harder-to-read","AI Coding Assistants Struggle as Code Gets Harder to Read","A new study finds DeepSeek-Coder-V2 and Llama both lose over a third of their accuracy predicting code behavior as functions grow more complex.","AI models that read code start to fail at exactly the moment reading code gets hard.\n\nA new benchmark tests two code-focused models, DeepSeek-Coder-V2 and Llama, on how well they understand Python functions as those functions get structurally messier. Researchers scored complexity using four established metrics - cyclomatic complexity, nesting depth, branching factor, and Halstead volume - then split 300 functions into low-, medium-, and high-complexity bands. On an automatic input-output prediction task, DeepSeek-Coder-V2 hit 78.33% accuracy overall and Llama hit 70.33%. Broken out by complexity, DeepSeek-Coder-V2 fell from 93.52% on simple functions to 52.78% on the hardest ones, and Llama dropped from 87.04% to 47.22%. A smaller, manually graded check of 60 functions showed the same slide: DeepSeek-Coder-V2 went from 100% to 75%, Llama from 90% to 60%.\n\nThat gap matters more than the overall accuracy figure. Code review, debugging, and refactoring in real codebases rarely involve the tidy, low-complexity functions these models handle well - they involve the tangled ones. A model that's reliable on toy examples but close to a coin flip on deeply nested, branch-heavy code is not one you'd want reviewing a pull request unsupervised.\n\nVendors keep publishing single accuracy numbers because single numbers make good marketing copy. This paper is a reminder to ask what the hard tail looks like before trusting one.","[\"ai\",\"llms\",\"code-review\",\"benchmarks\"]","2026-09-30T04:00:00.000Z","2026-09-30T16:04:44.967Z","2026-09-30T16:04:45.228Z","published",null,[],"ai",[24,26,27,28],"llms","code-review","benchmarks",[30],{"name":31,"url":32},"arXiv cs.AI","https:\u002F\u002Farxiv.org\u002Fabs\u002F2609.37405",0,{"sections":35},[36,39,43,47,52,57,62,67,72,76,81,86,91,96],{"name":37,"slug":24,"count":38,"latest_published_at":18},"AI",5147,{"name":40,"slug":41,"count":42,"latest_published_at":18},"Security","security",788,{"name":44,"slug":45,"count":46,"latest_published_at":18},"Policy","policy",417,{"name":48,"slug":49,"count":50,"latest_published_at":51},"Deals","deals",284,"2026-09-29T21:00:00.000Z",{"name":53,"slug":54,"count":55,"latest_published_at":56},"Hardware","hardware",194,"2026-09-29T13:16:04.000Z",{"name":58,"slug":59,"count":60,"latest_published_at":61},"Science","science",154,"2026-09-28T13:19:18.000Z",{"name":63,"slug":64,"count":65,"latest_published_at":66},"Consumer Tech","consumer-tech",142,"2026-09-29T18:38:03.000Z",{"name":68,"slug":69,"count":70,"latest_published_at":71},"Software","software",91,"2026-09-25T20:55:00.000Z",{"name":73,"slug":74,"count":75,"latest_published_at":18},"Dev Tools","dev-tools",90,{"name":77,"slug":78,"count":79,"latest_published_at":80},"Startups","startups",83,"2026-09-29T21:51:36.000Z",{"name":82,"slug":83,"count":84,"latest_published_at":85},"General","general",49,"2026-09-28T16:44:57.000Z",{"name":87,"slug":88,"count":89,"latest_published_at":90},"Gaming","gaming",48,"2026-09-25T18:35:21.000Z",{"name":92,"slug":93,"count":94,"latest_published_at":95},"Reviews","reviews",31,"2026-09-28T14:31:34.000Z",{"name":97,"slug":98,"count":99,"latest_published_at":100},"How-To","how-to",6,"2026-06-16T09:00:00.000Z"]