I would rate the solution's stability eight or nine out of ten.
WSO2 Identity Server is highly rated for stability, scoring approximately eight out of ten. It offers easy integration with Single Sign-On and external user sources, and the keystore is notably beneficial. However, the high availability architecture needs enhancement, and BPM workflows require external integration. Documentation inadequacies and limited out-of-the-box auditing and certification modules present challenges. Pricing and licensing lack flexibility, creating further improvement opportunities for tech buyers.