Thin film high entropy alloys (TF-HEAs) have recently gained interest for their large ductility and yield strength (up to 30% and 10 GPa respectively, for NbMoTaW) [1], as a results of the thickness confinement and the small grain size. In addition, the mechanical properties can be boosted by developing nanolaminate structures capable of blocking the propagation of dislocation and cracks [2]. However, the development of new TF-HEA architecture and the investigation of local mechanical properties exploiting in situ SEM techniques represent an open challenge. Here, we developed nanoarchitectured TF-HEAs by magnetron sputtering and pulsed laser deposition (PLD), enabling a fine control over the film morphology, and providing the possibility to design unique film architectures [3]. Firstly, we focus on the synthesis of nanostructured CoCrCuFeNi TF-HEAs. We report a compact to nanogranular transition for films deposited by PLD when the background pressure is >1 Pa (Fig.1). This results in a reduction of mass density (~15%) and elastic modulus (~8%), starting from 8.01 g/cm3 and 173 GPa respectively. Moreover, we show that TF-HEAs deposited by PLD have enhanced hardness (10.5 GPa) compared to magnetron sputtering (7.4 GPa), while showing exceptional ductility in tensile tests on polymer substrate (onset of crack formation 3.4%). In a second step, we fabricate Al/CoCrCuFeNi nanolaminates with a semicoherent interface (FCC/FCC) by PLD and sputtering, with a bilayer period (Λ) ranging from 2.5 to 200 nm. Despite a volume fraction of 50% for Al (H=1.5 GPa), nanolaminates by PLD are able to maintain high hardness up to 9.7 GPa (for Λ = 50 nm). Moreover, at smaller bilayer periods, we observe an inverse Hall-Petch effect, reducing hardness down to 8.4 GPa. Finally, I will present recent results involving the synthesis of new nanolaminates with an incoherent interphase, such as Al25CoCrCuFeNi/Al (BCC/FCC), while focusing on the development of in situ techniques such as micropillar compression (Fig.2) to understand the local deformation mechanisms.