Photons are powerful carriers of quantum information, and their temporal degree of freedom offers a particularly versatile route toward photonic quantum processing. In this talk, I will present recent experimental results on programmable photonic quantum circuits using ultrafast time-bin encoding, where quantum information is encoded in pulse sequences separated by only a few picoseconds. Operating in this ultrafast regime enables compact, passively stable time-delayed interferometry and flexible preparation, manipulation, and measurement of time-bin superpositions at the single-photon level. I will highlight proof-of-principle demonstrations that showcase how this platform supports a range of quantum information tasks, including communication protocols and quantum information processing primitives, and discuss why ultrafast temporal encoding is a promising direction.