Soboroff was President, then Chairman Emeritus of Big Brothers of Greater Los Angeles and has been involved with the program for nearly four decades. Following the merger with Big Sisters of Greater Los Angeles, Soboroff became a board member emeritus of Big Brothers/Big Sisters of Greater Los Angeles. As a college student, Soboroff volunteered for Big Brothers and became part of one of the first interracial matches in the program's history.
Soboroff's City Hall career was highlighted in the Simon & Schuster book by Taegan D. Goddard and Christopher Riback, YOU WON - NOW WHAT? How Americans Can Make Democracy Work From City Hall to the White House (1998).
While working as the chairman of the City's Harbor Commission, then as Senior Advisor to the Mayor, Soboroff helped spearhead the Alameda Corridor project and the Staples Center arena. As chairman of the citizens' oversight committee for the $2.4 billion Proposition BB school bond, Soboroff, advised by the environmental group TreePeople, oversaw a "greening" project that replaced thousands of acres of asphalt with grass and trees in Los Angeles public schools.
In 2005, many of the traffic-fighting proposals Soboroff introduced during his 2001 campaign, as well as his plan to break up the Los Angeles Unified School District (LAUSD), were reintroduced by other candidates in that year's mayoral contest. Later in 2005, newly-elected Los Angeles Mayor Antonio Villaraigosa, with whom Soboroff competed for the Mayor's job in 2001, implemented Soboroff's proposal to ban all road construction during rush hour. Villaraigosa's 2005 campaign manager, Ace Smith, played same roll for Soboroff in 2001.
In the 1990s, Soboroff was honored as Harvard Business School's "Business Statesman of the Year." He mentors students annually from UCLA and the University of Southern California, and has lectured on topics from real estate to electoral politics at Stanford University, UC Berkeley, Loyola Marymount University and the Maxine Goodman Levin College of Urban Affairsat Cleveland State University, Ohio. He holds Bachelor and Masters Degrees from the Dept. of Finance, Insurance and Real Estate at the University of Arizona.
In October 2001, six months after finishing out of contention in the Los Angeles mayoral race, Soboroff joined Playa Vista as the company's President.
Playa Vista is located on 1,087 acres between Marina del Rey, Westchester and Playa del Rey; the property is located just below the 150 acre, bluff-top Loyola Marymount University campus. The new community provides housing, commercial office space, neighborhood shopping, parks and habitat protection. The project's developers say Playa Vista is committed to sustainable development. Playa Vista has been recognized by the White House as one of five P.A.T.H. (Partnership for Advancing Technology in Housing) communities in the United States.
Soboroff oversees all aspects of the project near the ocean on Los Angeles’ Westside. Playa Vista was described by the Los Angeles Times as “L.A.’s Urban Model”.
According to the Los Angeles Times, "[o]ver the last decade, government agencies and courts have ruled repeatedly in Playa Vista's favor [...] Engineers, builders and consultants for the project have joined the city of Los Angeles in saying the safety measures are the most elaborate the city has ever required [...]
Foes of the development, however, continue to question how tests were conducted. They also say that the systems for monitoring and mitigating methane are unproven and could fail, threatening a deadly explosion in new homes and offices." (Groves "Buyers" 2003). However, many proponents of Playa Vista call these fears overblown, as large parts of nearby Marina del Rey and Venice face similar methane accumulation issues but lack any sort of mitigation measures altogether