Mandell has worked in database software design and development for more than 20 years, developing solutions for the pre-press and t-shirt printing industries including job tracking and cost accounting. He has developed software for the museum, library and archive industries, focusing on fundraising systems, job tracking for artwork conservation, cataloging software across all three industries, and has developed software for digital preservation. He also wrote software that aided Raytheon electrical engineers in designing circuit boards for weapons.

Mandell was the lead developer for the Archivists’ Toolkit, a software application funded in the amount of $847,000.00 by the Andrew W. Mellon Foundation to support archival processing and the management of archival information. He oversaw the toolkit from inception through multiple production releases. He has 11 years’ experience in hydroponic system design, installation, operation and training, and for eight years operated Boswyck Farms, a hydroponic teaching farm in New York City. He has developed a hydroponic certification course outlining job training, hydroponic farm maintenance and operation, crop care and management efficiency, and he designed and installed the first indoor hydroponic grow rooms in food pantries in the country.

Mandell has also worked extensively with local schools using hydroponics to teach science to underserved populations, and was key in getting the urban agriculture movement in New York City off the ground while working with Anastasia Cole Plakias and the team who started the Brooklyn Grange rooftop farming and green space creation movement.

Mandell has designed, built and maintained aquariums for a wide variety of freshwater and saltwater tropical fish including African cichlids, which he also breeds. He has six years’ design directorial experience working with theater, dance, cabaret and performance art. He also served as the production manager who recorded the 2009 Brooklyn Food Conference.