Big joined Allford Hall Monaghan Morris in 2008 after completing her architecture studies at the Leibniz Universität Hanover in Germany. From 2008 to 2010 she worked on the Angel Building leading the internal packages, and her role continued though site works to completion. Following another project for Derwent London at 132 -140 Hampstead Road, she led a team designing a masterplan for the Tower Bridge Business Complex, and delivered the successful planning application. In 2012 Big became Project Architect on the first phase of the award-winning University of Amsterdam Roeterseiland Campus, where two existing 1970s campus buildings have been reinvented with a retained, but greatly modified, structural frame. Big became a Senior Architect in 2015 and has recently led a team on Google Berlin, a new Google office and YouTube Studio space in a listed historic hospital building in central Berlin. She is currently working on the refurbishment and extension of existing building complex containing hotel, office, and retail on Berkeley Street in London. She was promoted to Associate in 2021.