Hotiday, a Milan-based startup that sublets hotel rooms and rents them to travelers, tops the third Sifted 100: southern Europe Leaderboard — an annual ranking of the 100 fastest-growing companies in the region, in partnership with AI infrastructure company Nebius.In second place is Lexroom, also based in Milan. The company provides AI tools for small law firms and corporate legal teams, and raised a $50m Series B this week.Third is Barcelona-based Enginy, an AI platform to help salespeople find potential customers. The leaderboard ranks 100 companies with the strongest revenue growth over the past three financial years, calculated using a two-year revenue compound annual growth rate (CAGR). Founded by a trio of students in 2022, Hotiday notched a 1330.95% two-year revenue CAGR between 2023 and 2025."When we started we thought, we can't just buy buildings, and we can't franchise the brand," says cofounder and CEO Vittorio Gargiulo. "But we can sublet." Sifted Pro subscribers can learn more about the startup’s unusual business model here. Paolo Fois, cofounder and CEO of Lexroom, leads his company to a 1129.64% CAGR; Enginy, with an 889.61% CAGR, is targeting €10m annual recurring revenue by the end of the year. CEO Kai Brand is building the business the modern way: through his LinkedIn.An avid poster, Brand has turned his profile into a sales engine. "Building that presence has helped a lot in our outbound sales," he says. "You build a voice on social media so customers already trust and know our products when they get a cold call."Milan, B2B triumphsFor the third year in a row, business-to-business software is the top-performing vertical on the ranking with 32% of companies, slightly down from 37% in 2025 and 38% in 2024. Nine climate tech startups make the cut, while 13 companies are AI-native — meaning they have designed their products around the technology. Lexroom is the top-ranked among them.The majority of the ranked companies (27) are based in Milan. Barcelona is home to 14 startups, and Madrid seven.Six companies in the top 100 have already raised funding in 2026. Of those, Lexroom has raised the biggest amount.The 10 fastest-growing startups in southern Europe in 2026:1/ Hotiday: Hotel booking site2/ Lexroom: AI tools for lawyers3/ Enginy: AI-powered sales platform4/ Jet HR: Payroll and HR software 5/ reveni: E-commerce software to help manage returns6/ Plannix: Financial advisory platform 7/ toduba: Software to manage meal vouchers and gift cards 8/ Embat: AI tools for chief financial officers 9/ qomodo: Buy now, pay later tool for Italy’s main-street retailers10/ e-motion: EV charging hardwareView the full, digital version of the leaderboard here.How the 100 were chosenTo be eligible, companies had to meet the following criteria: