  Due to a beneficial balance of computational cost and accuracy, real-time
time-dependent density functional theory has emerged as a promising
first-principles framework to describe electron real-time dynamics. Here we
discuss recent implementations around this approach, in particular in the
context of complex, extended systems. Results include an analysis of the
computational cost associated with numerical propagation and when using
absorbing boundary conditions. We extensively explore the shortcomings for
describing electron-electron scattering in real time and compare to many-body
perturbation theory. Modern improvements of the description of exchange and
correlation are reviewed. In this work, we specifically focus on the Qb@ll
code, which we have mainly used for these types of simulations over the last
years, and we conclude by pointing to further progress needed going forward.
