The Companion Proceedings of the 21st Brazilian Symposium on High-Performance Computing Systems (SSCAD 2020) bring the papers selected and presented on the Internet from the 21st to the 23rd of October, 2020. The companion proceedings of SSCAD 2020 comprise the 21st Undergraduate Research Workshop (WIC 2020) and the 15th Workshop Sobre Educação em Arquitetura de Computadores (WEAC 2020).

In this issue, the companion proceedings of the 21st Undergraduate Research Workshop (WIC 2020) include 16 full papers. These papers were selected through a blind review, from a total of 18 full papers submitted, which implied an acceptance rate of 88%, respectively. The event's program committee was coordinated by Denise Stringhini (UNIFESP) and João Vicente Ferreira Lima (UFSM), who organized this volume. The articles in this volume were submitted on 28/08/2020, accepted for publication on 29/09/2020, with the final version submitted on 06/10/2020.

You can find more information about WIC 2020 by visiting the website of the event.

The Companion Proceedings of the 15th Workshop Sobre Educação em Arquitetura de Computadores (WEAC 2020) bring the papers selected and presented by the authors on October 21st, 2020. In this issue, the proceedings include 03 full papers. These papers were selected through a blind review, from a total of 03 full papers submitted, which implied an acceptance rate of 100%. The event's program committee was coordinated by Carlos Augusto Paiva da Silva Martins (Pontifícia Universidade Católica de Minas Gerais), who organized this volume. The articles in this volume were submitted on 09/13/2020, accepted for publication on 10/02/2020, with the final version submitted on 10/11/2020.

You can find more information about WEAC 2020 by visiting the website of the event.

To access the main proceedings of SSCAD, visit the Proceedings series of SSCAD 2020.