This article examines the development of engineering and computational thinking within the framework of STEM education. The purpose of the study is to empirically assess the level of engineering thinking among school learners and university students engaged in STEM-oriented learning and to analyze its relationship with academic achievement in computer science. The study involved school learners from Kazakhstan and 50 undergraduate students from the Department of Informatics at M. Auezov South Kazakhstan University. Research instruments included the Computational Thinking Scale (CTS) and author-designed test tasks, with data analyzed using Item Response Theory (IRT). The relationship between engineering thinking and academic performance was examined through regression analysis. The results indicate that STEM-based instruction significantly enhances algorithmic thinking, modeling skills, and problem structuring abilities. The findings confirm the effectiveness of STEM education in fostering engineering thinking and provide practical implications for educational practice.