1 Malmö University, Sweden 2 Vrije Universiteit Amsterdam, The Netherlands 1 The 15th European Conference on Software Architecture (ECSA 2021) Tools and Demonstrations (Tools&Demos) Track provided an opportunity for both researchers and practitioners to present and discuss the most recent advances, ideas, experiences, and challenges in the field of Software Architecture by means of Tools&Demos presentations. Tools&Demos papers were intended to address any aspect of (i) tool support for Software Architectures or (ii) demonstrate results about the application of architectural approaches. Papers submitted to this track belong to two distinct categories: • Tools: academic or industrial artefacts, with a specific purpose, that can be used by others. Tools should particularly show how scientific approaches related to software architecting have been or are being transferred into a working tool and how they advance the current state of the practice. • Demonstrations: academic or industrial exhibition of some result that explains how a novel or existing approach related to software architecting has been applied and possibly benchmarked. The Tools&Demos Track this year received five submissions and each paper went through a rigorous evaluation process. Papers were reviewed by at least three reviewers followed by a discussion. At the end of the process, three papers were accepted and discussed. The Program Committee members were: • Justus Bogner, University of Stuttgart • Barbara Buhnova, Masaryk University • Rami Bahsoon, University of Birmingham