A key figure of merit of quantum technologies is the ratio between two characteristic times: the (decoherence) time during which a quantum state remains well defined and the time it takes for operating the device. Most technologies inherently work at the nano-second scale, hence concentrate on fighting decoherence processes. The goal of UltraFastNano is to pioneer new concepts at the crossroads between quantum optics and solid-state nanoelectronics at the pico-second scale, almost three orders of magnitude faster than other quantum technologies. Using fermionic flying excitations created with pico-second controlled voltage pulses at cryogenics temperatures (10 mK), we envision achieving full control of quantum excitations that propagate through electronic devices. A key deliverable of UltraFastNano is (i) the demonstration of the first electronic flying quantum bit, a paradigm-shifting approach to quantum computing and quantum communication. Besides, such a technology would enable major new applications such as (ii) electronic sources and detectors that operate at the picosecond scale; (iii) picosecond optoelectronic devices that convert between electronic and photon pulses; (iv) beyond state-of-the-art metrological measurement of the ampere. To achieve this vision, UltraFastNano will establish a unique unprecedented platform for creating, manipulating and detecting quasi-particles excitations at the single-electron level in semiconductor heterostructures. We will unlock two major technological bottlenecks: a picosecond on-demand coherent single particle source and the single-shot detection of propagating excitations at the discrete charge level. UltraFastNano gathers a team with complementary expertise in quantum nano-electronics, optics, nano-fabrication, microwave electronics, cryogenics, theoretical physics, applied mathematics and software engineering. The partners are internationally recognised for having played a key role in the emergence of the field.