← Back to PeopleResearcherJustus MatternCo-Founder at ProximalLinkedIn@MatternJustusWebsiteCo-Founder at Proximal1Mentions1Articles1OutletsArticlesMost recent firstMentioned InReferenced in coverageFrontierSWE: Ultra-Long-Horizon Coding BenchmarkXcautiousApr 17, 2026“Justus Mattern introduced FrontierSWE, an ultra-long-horizon coding benchmark with tasks running up to 20 hours where frontier agents rarely succeed.”