How Paul Kromidas Took Summer From Asset-Heavy to AI-First—and Built the STR Operator OS of the Future

Paul Kromidas didn’t just pivot a startup—he changed the vehicle mid-race and still pulled ahead. Summer began as an asset-heavy “own an STR without the risk” model: Summer found the house, bought it with their capital, operated it for two years, and sold it back with a book of business. It worked—until the capital stack and rate environment made venture-scale returns incompatible with real estate velocity. So Paul did the brave thing founders talk about but rarely do: he sold the homes, kept the brains, and rebuilt Summer around the software that had quietly powered V1. That software—Summer OS, now supercharged by Sunny AI—acts like a true asset-management layer for short-term rentals. It stitches market underwriting to unit-level P&L, pipes into your PMS, flags issues before they become reviews, and guides both pros and serious first-timers from “where should I buy?” to “how do I out-operate the comp set?” It’s not a wrapper around generic answers; it’s a working analyst that shows its work. Today on the show, I’m joined by Paul Kromidas—founder of Summer—on building tools that help operators decide, buy, and perform.In this episode, we: Explore why venture returns and deed-on-title don’t rhyme—and how an honest boardroom conversation led to selling the portfolio and doubling down on software. Discuss what an STR “asset management system” really is—linking market selection, underwriting, expense modeling, and live ops into one pane of glass. Explore how Sunny AI turns fuzzy intent into investable action—guiding you through clarifying questions, surfacing the right comps, and recommending markets you didn’t have on your radar. Discuss the difference between high-level market data and operator-grade decisions—and why posting performance back to the model is where comp-set truth lives. Explore who it’s for today (multi-market PMs and serious operators) and how the roadmap invites the rising class of under-20-door owners without dumbing anything down. Discuss the next frontier: using predictions to fix tomorrow’s dip today—so hosting feels less like firefighting and more like running a dialed business. If you’re building a portfolio—or rebuilding your ops stack—this one will sharpen how you underwrite, staff, and scale.