After earning her Bachelor of Fine Arts from RISD in 2008, Walsh moved to New York City. to intern at the notable design firm Pentagram. She turned down a job at Apple where she was offered nearly $100,000 annually to accept the internship under Paula Scher at Pentagram, where she would stay for nearly a year. She then worked as an associate art director at Print magazine and had design work and illustrations featured in various books, magazines and newspapers, including the New York Times and New York Times Magazine. In reflections about her time at Print magazine, she identifies it as one of the best things to happen in her career as it was how she found and developed her personal style. In 2010, Walsh met Stefan Sagmeister. He looked through her portfolio and offered her a job at his design studio, Sagmeister Inc. In June 2012, after two years at the firm, Walsh was made partner, at age 25. In homage to a nude self-portrait Sagmeister had sent out to announce the formation of his own firm 19 years prior, the new partners released a photo of themselves naked in their office to announce the renaming of the firm to Sagmeister & Walsh. Blending handcraft, photography and painting withdigital design, Walsh works primarily on branding, typography, website design and art installations. Her signature style has been described as "bold, emotional and provocative" with the occasional surrealistic flourish, and her art has been said to look "hand-made and at times quite daring." Walsh has worked on projects for clients including Levi's, Aizone, Adobe and Colab Eyewear, and rebranding efforts for The Jewish Museum of New York and the Aldrich Contemporary Art Museum in Connecticut. Walsh and Sagmeister collaborated on Six Things: Sagmeister & Walsh, an exhibition that opened at the Jewish Museum in March 2013, and ran for five months. For the exhibit, an exploration of happiness, they created a sound-activated sculpture and five short films. In July 2019, Walsh announced she was leaving Sagmeister & Walsh and forming her own studio, & Walsh. Walsh has said that the studio is a fulfillment of her dreams as a teen to run her own business and the studio will become one of 36 female-led creative studios in the United States.
''40 Days of Dating''
In 2013, Walsh and fellow designer and friend Tim Goodman decided to date for 40 days to see if they could overcome their relationship issues and fall in love. They documented the social experiment on a blog, , launched in July 2013. In support of the blog, which earned more than 5 million unique visitors in less than a year, they appeared in segments on talk showsToday and The View. In September 2013, Warner Brothers purchased the film rights, with a screenplay to be written by Lorene Scafaria, and Michael Sucsy attached to direct. Walsh and Goodman will serve as consulting writers on the script and also wrote a book for Abrams, 40 Days of Dating: An Experiment, out in early 2015.
''12 Kinds of Kindness''
In 2016, Walsh and Goodman began a second project together, which they described as a "12-step experiment designed to open hearts, eyes, and minds". They set up twelve tasks in which they displayed kindness to people and recorded the results. The experiment was live from January 13 to March 15, 2016.
Ladies Wine and Design
Walsh started Ladies, Wine & Design, a nonprofit organization to encourage women to work together rather than compete, in 2016., the organization has 273 local chapters around the world.