$t\overline{t}W$ Production: A very complex process.

Despite its complexity, both from the theoretical and experimental side, the ttW process is very attractive and has rich phenomenological applications. This process can lead to final states that contain two same-sign charged leptons, present in rare Standard Model (SM) processes (such as ttH and 4-tops production) and also indispensable in searches for physics beyond the SM (BSM). Furthermore, the presence of the W-boson polarises the initial quark-line and in turn the final tt-pair. This polarisation and asymmetry effects in ttW production can additionally offer a useful handle to constrain new physics. So far, only cross-sections have been measured at the LHC, and some tension has been observed between the SM predictions and data which warrants further study of this process from both the experimental and the theoretical sides. Higher order effects are very relevant for ttW production. In the absence of gluon-induced channels at LO, the latter only appear at higher orders and give sizeable contributions to the cross section. Furthermore, electro-weak contributions are not as negligible as expected due tW->tW scattering contributions, which impact the overall cross-section prediction and also have kinematic effects. On this line, several developments have been carried out to improve our ATLAS ttW Monte Carlo simulations to include higher order effects (using NLO multileg setups, such as FxFx) and EW corrections. The latest studies on this will be presented in this contribution.