Docusign CEO Allan ThygesenCourtesy Docusign At DocuSign headquarters in San Francisco, near the city’s waterfront with sweeping views of the Bay Bridge, visitors are greeted by a mural of a signature on an aquamarine wall. It’s not the signature of anyone in particular; company reps say they don’t know who it belongs to. On a nearby wall, a framed plaque commemorates National E-Sign Day (June 30, 2010), a congressional holiday that celebrates the law passed a decade earlier that made e-signatur...