The twelfth IEEE Working Conference on Software Visualization (VISSOFT 2024) builds upon the success of the previous ten editions of VISSOFT, which in turn followed after seven editions of the IEEE International Workshop on Visualizing Software for Understanding and Analysis (VISSOFT) and five editions of the ACM Symposium on Software Visualization (SOFTVIS). In 2024, VISSOFT will take place and be co-located with ICSME.