In many contexts worldwide, educators are encouraged to integrate/interrelate aspects of science, technology, engineering and mathematics (STEM). Among STEM education variants, promotion of students’ engineering design expertise and appreciation of engineering products and services seem particularly prevalent. While there are many defenders of such foci, several scholars suggest that many STEM education initiatives compromise students’ consciousness of adverse effects (e.g., relating to the climate crisis) on living and nonliving things of influences of powerful people (e.g., financiers) and groups (e.g., corporations, free market think tanks and transnational groups like the World Trade Organization) on STEM fields and beyond. Accordingly, we report action research findings involving a secondary school science teacher’s efforts to educate students about such problematic relationships and, for areas of their interest, enable them to design and implement functional engineering products that also address their social justice and/or ecological vitality priorities—within and beyond the products. Analysing qualitative data (e.g., teacher’s lesson materials and students’ completed assignments) using constructivism-informed constant comparative methods, we concluded that secondary science students are quite capable of developing and implementing various functional ecojust technologies and that such experiences can change their ontological, epistemological and axiological positions. Contributing to such results appeared to be the teacher’s uses of application-based teaching to help students understand, for example, compromises in engineering design. Having said that, it also appears that much action research is required to explore ways to improve aspects of students’ ecojust engineering designs, such as their concepts of agency of non-human and non-living things.