The 21th IEEE International Symposium on Parallel and Distributed Processing with Applications (IEEE ISPA 2023) is a forum for presenting leading work on parallel and distributed computing and networking, including architecture, compilers, runtime systems, applications, reliability, security, parallel programming models and much more. During the symposium, scientists and engineers in both academia and industry are invited to present their work on concurrent and parallel systems (multicore, multithreaded, heterogeneous, clustered systems, distributed systems, grids, clouds, edge, and large scale machines). The 21th IEEE ISPA 2023 will be hosted in Wuhan, China. We have had 3 papers accepted.