This editorial introduces the special issue on High Assurance Systems Engineering concepts for safe, secure, and reliable software systems in the Journal of Software: Evolution and Process. The nine papers published in this special issue were selected from extended versions of papers presented at the 2016 IEEE International Symposium on High Assurance Systems Engineering (HASE 2016) held in Orlando, Florida, through a highly competitive review process. The papers propose and discuss emerging solutions that address at least one of the three characteristics identified as foundational requirements to design, verify, and operate contemporary high assurance software systems: safety, security, and reliability, though, several papers consider a combination of these requirements, by modeling software system dependability and/or system resilience in the face of operational changes. The modeling aspects of the papers include fault‐tolerant design and analysis, online logic adaptation, decision and risk analysis, malware detection, and disaster management solutions, as well as several formalized testing and verification techniques.