Resolution of a near-wall turbulent boundary layer is still a hot topic in fluid dynamics. It is well-known that the resolution of a tiny near-wall region might require most computational time. A consequent high-resolution of this layer is as computationally expensive as direct numerical simulation [1]. Conversely, engineering approaches based on wall functions avoid a detailed resolution of the near-wall region. However, they might be too inaccurate and emprical. A non-overlapping domain decomposition method (NDD) [2] has turned out is quite efficient in tackling the problem in question when the model of the Reynolds-averaged Navier-Stokes (RANS) equations is exploited. The method is much more universal than conventional approaches based on wall functions because it does not use any free parameters to be tuned. In this approach the computational domain is split into two non-overlapping domains: the inner (near wall) and outer regions. In the inner region, the model of the thin-boundary layer equations is used. A key problem is related to the interface boundary conditions (IBC). IBC are obtained via the transfer of the boundary conditions from the wall to the interface boundary. It is important that they can be obtained without the solution of the problem in the outer region. This results in IBC that are nonlocal and of Robin type. They guarantee that the composite solution is smooth. The domain decomposition was realized implicitly via a predictor-corrector algorithm in [3]. At the predictor stage, the solution is obtained in the entire region with specially derived slip boundary conditions at the wall. This approach has been applied to RANS-LES decomposition in [4]. It is demonstrated that the composite instantaneous solution is smooth. In this paper, the perspectives on the extension of NDD to essentially unsteady problems are also discussed in detail. REFERENCES [1] P. Sagaut, Large Eddy Simulation for Incompressible Flows. An Introduction, Springer, 2006. [2] S.V. Utyuzhnikov, Domain decomposition for near-wall turbulent flows, Computers & Fluids, 2009, 38 (9): 1710-1717. [3] S. Lyu, S. Utyuzhnikov, A computational slip boundary condition for near-wall turbulence modelling, Computers & Fluids, 2022, 246 (10): 1-13. [4] A. Fard, S. Utyuzhnikov, A hybrid Large Eddy Simulation algorithm based on the implicit domain decomposition, Mathematics, 2023, 11, 4340.