Diamond Open Access is a scholarly publishing model characterized by journals and platforms that do not impose fees nor on authors neither on readers. These journals typically operate as community-driven, academically-led, and academically-owned initiatives. While this approach does not eliminate publishing costs entirely, it places a strong emphasis on achieving fairness (FAIR principles). Several frameworks are available to facilitate this approach, where the minimum is to manage content storage and visibility. An alternative strategy to reduce the workload for editors of such journals is the adoption of an Overlay journal approach, which curates and selects content from freely accessible online repositories, such as preprints. In this setup, editorial boards supervise the peer review process to ensure high-quality content and rely on institutional storage repositories like ArXiv, HAL, and Zenodo for data retention. To illustrate the advantages and challenges of this model compared to traditional scientific journal approaches, we will use the Journal of Theoretical Computation and Applied Mechanics (JTCAM) as an example. JTCAM's commitment to open reviews, meticulous copy-editing, and its innovative approach to reviewing datasets will be discussed in detail.