Abstract. Context. Development of safety-critical systems is mostly governed by process-heavy paradigms, while increasing demands on flexibility and agility also reach this domain. Objectives. We wanted to explore in more detail the industrial needs and challenges when facing this trend. Method. We launched a qualitative survey, interviewing engineers from four companies in four different industry domains. Results. The survey identifies human factors (skills, experience, and attitudes) being key in safety-critical systems development, as well as good documentation. Certification cost is related to change frequency, which is limiting flexibility. Component reuse and iterative processes were found to increase adaptability to changing customer needs. Conclusions. We conclude that agile development and flexibility may co-exist with safetycritical software development, although there are specific challenges to address.