Carbon electrode-based perovskite solar cells (C-PSCs) are a promising innovation in solar cell technology. For their industrial development, an innovative perovskite deposition method using inkjet printing (“ink”) is compared with the more user-friendly drop-casting process (“drop”). Perovskite solar cells face challenges related to sensitivity to moisture and heat, prompting an investigation into their aging behavior under damp heating conditions for both deposition processes. Results reveal significant differences in aging behavior. Performance measurements demonstrate that drop-cast solar cells have a lifetime roughly three times longer than ink-deposited ones, despite initial similar performance. Drop-cast solar cells exhibit an impressive lifespan of ≈3000 h. Various characterization techniques are employed to understand the role of interfaces in C-PSC degradation. Diffraction analyses reveal structural disparities between the two cell types, while spectroscopic measurements reveal substantial degradation of charge transfer mechanisms in ink-deposited cells, leading to pronounced radiative recombination. These findings highlight the critical influence of deposition method and active layer thickness on device stability. Optimization is imperative to achieve stable and efficient C-PSC devices. In summary, C-PSCs hold great promise, but their performance and longevity are intricately linked to deposition techniques and interface properties, necessitating careful engineering for practical application.