After opening an architecture practice in 1989, Giroud broadened his design work to other areas, including graphic design, packaging, writing instruments, lighting fixtures, furniture, and electronics. He designed his first watch in 1997 and established a watch design office the following year.
One of Giroud's first high-profile designs was of the Sequential One for MCT. This used rotating triangular “blades” to display the hour digitally alongside a rotating minute hand. Another digital display was the Swarovski D LIGHT, which illuminated the time on demand behind a grid of crystals. But his most important early work was the 2008 Harry Winston Opus 9, which displayed the hour and minute with red garnets in two chains of diamonds that rotate longitudinally around the watch case. This watch won the GPHG in 2009, his second such award after the Harry Winston Tourbillon Glissière two years earlier. Giroud also worked with Badollet, Rebellion, Tissot, and Heritage Watch Manufactory at this time.
Giroud's major work in the 2010s was with MB&F. He collaborated with Max Büsser and other watchmakers on the design for every entry in the MB&F Horological Machine line starting with the Horological Machine N. 1. The Horological Machine N. 5 is a mechanical digital watch that shows the time using luminous material on two discs. Giroud also helped with the Legacy Machine N. 1 and Horological Machine N. 6. He also redesigned the Pierre Arpels watch for Van Cleef & Arpels and worked with Manufacture Royale and Mathey-Tissot at that time. He finished the decade with a successful collaboration with Louis Erard.