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.

Connect with Paul

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