Sergio/Keller Williams Realty

Sergio is a Keller Williams agent working out of the brokerage's Quincy office on Washington Street. His web presence is a Keller Williams-hosted agent page — the brokerage's own property search, its market-update blog, its franchise and recruiting pages — and the site states the business operates under Keller Williams Realty. That brokerage tie is the one thing established here, and it comes from the company's own site rather than from anyone who has worked with him. If you're weighing him for a sale or a purchase, go straight to the specifics: ask for closings in Quincy and the surrounding South Shore towns over the past year, references from buyers and sellers on both sides of those deals, and his Massachusetts salesperson license number so you can check it against the state registry yourself.