Add3 is a company that hides in plain sight. You may have never heard of the Capitol Hill tech firm, but you’ve almost certainly seen their work. It’s also entirely possible you don’t know where they’re located even though you’ve likely been inside the building they’ve called home — and the location of their coming-soon new Capitol Hill offices.

Add3’s focus is optimizing Internet search for businesses. The firm helps companies get their links into coveted spots at the top of Google and Bing search results and counts Match.com, Costco, and AT&T among their clients.

Brian Rauschenbach launched Add3 in 2010 after nearly a decade of working in the search arena. Currently Rauschenbach and his 25-person company reside in an office space directly above the Elysian Brewery.

Over the past year, Rauschenbach said he and his business partners decided to stop building websites and ads for their clients, and narrow their focus exclusively to search. Rauschenbach said honing Add3’s scope allowed the company to expand by hiring more people skilled in search marketing. “It was easier to scale for us with a tighter focus,” he said.

That meant the company needed room to grow.

The current state of the new Add3 office, above the former Brocklind’s space.

Add3 found that space above the former Brocklind’s shop at Summit and Pike. Rauschenbach said will likely move into their new office in October. Downstairs, work is continuing on the future home of a Roman-style trattoria from familiar neighborhood restauranteur Quentin Ertel. Developer Hunters Capital acquired 500 E Pine soon after Brocklind’s shuttered after 106 years in business and is restoring the building to its auto row era glory.

To coincide with their grown-up start-up phase, Rauschenbach said he’s bringing in an interior designer to create the ideal start-up office: one that’s aesthetically complete with room to grow.

Outside of search, Rauschenbach keeps busy with several other ventures on the Hill . He is an active co-owner at Captain Blacks and 95 Slide, as well as a silent investor in The Saint, Havana, and Molly Moons. When not running around with his 3-year-old, he makes irregular appearances DJing at Barboza and Moe Bar.

Rauschenbach is also the co-founder and curator of the Seattle Interactive Conference, which will hold its third annual event in October.