The ΛCDM model faces tensions between different cosmological data sets, which are interpreted as either systematic errors or missing physics. To resolve these tensions, it is essential to check the consistency of the ΛCDM model by examining its parameters at different redshifts and scales. This approach helps identify whether the model's parameters change with redshift or scale, indicating a breakdown of the model. The paper reviews the assumptions underlying the ΛCDM model and discusses how relaxing these assumptions might help resolve tensions. It highlights recent progress in addressing the $ S_8 $ and $ H_0 $ tensions, emphasizing the importance of localizing missing physics in the redshift range. The paper argues that the $ H_0 $ tension, which is redshift-dependent, and the $ S_8 $ tension, which is scale-dependent, suggest a problem with the background ΛCDM cosmology. The paper also discusses the implications of these tensions for the ΛCDM model and the need for further consistency checks to determine whether the model is valid or requires modification.The ΛCDM model faces tensions between different cosmological data sets, which are interpreted as either systematic errors or missing physics. To resolve these tensions, it is essential to check the consistency of the ΛCDM model by examining its parameters at different redshifts and scales. This approach helps identify whether the model's parameters change with redshift or scale, indicating a breakdown of the model. The paper reviews the assumptions underlying the ΛCDM model and discusses how relaxing these assumptions might help resolve tensions. It highlights recent progress in addressing the $ S_8 $ and $ H_0 $ tensions, emphasizing the importance of localizing missing physics in the redshift range. The paper argues that the $ H_0 $ tension, which is redshift-dependent, and the $ S_8 $ tension, which is scale-dependent, suggest a problem with the background ΛCDM cosmology. The paper also discusses the implications of these tensions for the ΛCDM model and the need for further consistency checks to determine whether the model is valid or requires modification.