Understanding the role of T cells in mediating protection from COVID-19 is an active area of research. Since T cells recognize short linear peptides, it is often challenging to experimentally identify these precise fragments (T cell epitopes), given the large number of potential candidates. Computational approaches are useful in reducing the space of candidate peptides to test and thus expedite epitope discovery. At the start of the pandemic, we were challenged by the lack of knowledge about T cell epitopes of SARS-CoV-2, the causative agent of COVID-19. We developed a web-based dashboard, COVIDep1, which leveraged experimentally known SARS-CoV-1-derived T cell epitopes to screen SARS-CoV-2 genetic sequences and predicted targets of T cells in COVID-192. COVIDep guided several experimental studies on T cell responses throughout the pandemic. As the pandemic progressed, we collated experimentally observed T cell epitopes of SARS-CoV-2 from across multiple studies and across different geographical regions. By synthesizing this information together with the genetic sequence data of SARS-CoV-2, we summarised the emerging landscape of T cell targets in COVID-193. This led to identification of conserved and immunoprevalent targets of T cells which can be prioritized for understanding T cell responses at the population level. By benchmarking the performance of state-of-the-art in silico prediction methods in the context of experimentally known T cell epitopes of SARS-CoV-2, we proposed a novel approach that improves prediction performance4. In the wake of COVID-19 variants, T cell epitopes conserved across these variants were quickly identified using the developed approaches. The dominant epitopes conserved in newer variants, such as Omicron and its sub-lineages (BA.5, BA.2.12.1, etc.), are likely targeted by vaccine or prior infection-induced immune responses5. Moving forward, the developed computational frameworks can guide the study of T cell responses going beyond COVID-19 and inform design of next-generation variant-proof and pan-coronavirus vaccines.