“The past five years have seen many changes to the city’s landscape, and most of them began on drawing boards in a hip, airy, second-floor suite of offices on Jay Street.

Pick a development, from the amphitheater in Central Park to the makeover of the old Maqua building looming over I-890, and you’ll find a design by Synthesis Architects.

The firm, led by John Senisi, Michael Szemansco and Richard Eats, has had a role in virtually every significant project in Schenectady since 1996. Their projects tend to inspire oohs and ahhs from the public that uses them and the politicians that commission them.

“I think one of the things that they’ve got going for them is their involvement in the community,” said Mayor Albert P. Jurczynski, calling Synthesis a “good-quality organization.”

“They’re pro-Schenectady,” the mayor said. “I know that they do work outside the city, but you always know that they understand the dynamics involved in Schenectady when they work on a project, and I think that has contributed to their success.”

The firm has designed, or is designing, projects including the reconstruction of State Street, Seward Place, upper Union Street and the Jay Street pedestrian mall.

Senisi and company have produced renderings, sometimes at no charge, for the Schenectady city government and Schenectady 2000 as the community works toward a clear vision for its future downtown.

Outside Schenectady, examples of Synthesis work include the new Progressive Insurance building in downtown Albany, the corporate offices of the General Electric Research and Development Center in Niskayuna, the Cancer Center at Albany Medical Center Hospital, and a cafeteria at the Pittsfield, Massachusetts GE plant.

The company has been hired to re-design Lark Street in Albany, and to write design guidelines for buildings in the city’s C-1 commercial districts.

Along with another Schenectady company, Transportation Concepts, Synthesis will do a study of how to best use 265 acres along South Troy’s waterfront, and is working on a study of how to improve vehicular and pedestrian traffic on the campus of Rensselaer Polytechnic Institute.

But it is here that the Synthesis vision dominates. The firm is leaving its mark on Schenectady in a way that no firm has since Feibes & Schmitt designed some of downtown’s most prominent buildings in the 1970’s.

Its influence will go much further if the newly released downtown master plan is adhered to, because Synthesis was deeply involved in researching and writing the plan.

The company also does less glamorous, lower-profile private-sector work for clients such as the New Country chain of auto dealerships. But Senisi, 45, and Eats, 52, said they are drawn to the municipal design work out of civic pride.

“I wanted to get into something that was different, the urban design stuff, high-profile projects,” said Eats, a Mont Pleasant native who joined Synthesis in January 1999. “And truly, I saw the city coming back and I wanted to be part of that.”

“We truly care about the city,” Senisi said. “We’re on the verge of really expanding what the city can be like in the next 10 or 20 years.”

Senisi is a designer of buildings, exterior and interior. Eats is a landscape architect. Expertise in the two disciplines broadens the services Synthesis can offer and results in better projects, the principals said.

The firm’s Jay Street office, stylish enough for Boston or San Francisco, is a quietly busy place, with young architects drafting on large computer screens. The staff has grown from around a dozen a year ago to 21 today, and Senisi and Eats said they are almost out of room. (They promised to stay downtown when they move to bigger quarters.)

The firm wants to be busier. The Synthesis of the future will be a builder, not just a designer: “We really want to expand into construction,” Senisi said.

Senisi, a New York City native who grew up in Poughkeepsie, graduated from Syracuse University with a degree in English in 1976 and went back to school to study architecture at Virginia Tech.

After college, he worked a series of jobs before landing in the Capital Region and working for Stracher Roth Gilmore, now a competitor whose own Jay Street office is almost directly across the street. Senisi founded Synthesis with Szemansco in 1988.

Eats graduated from West Virginia University with a degree in landscape engineering in 1971. He was a planner for the city of Schenectady for a year and a half, worked at CT Male Associates after that, then founded Environmental Design Partnership in 1977. He left that company to join Synthesis.

Eats’s Environmental Design Partnership drew up the plans for the Stockade Gateway project at Erie Boulevard and Union Street, and worked with Synthesis on the Jay Street reconstruction.

Eats is a nephew of a political titan, Dr. Fred Isabella, the former state senator and city councilman.

Senisi said the firm’s philosophy is that any project can be designed well, that less expensive need not mean less attractive. He lamented the tendency of developers to sacrifice beauty to save money.