This case study examined Czech electrical engineering and informatics students' English academic writing, addressing challenges in producing understandable and coherent texts for international audiences. Using a mixed-methods approach, which included textual analysis of essays, student writing profiles, and pre/post-course questionnaires, we analysed students' self-efficacy expressed in writing confidence, comfort, and competence. A language awareness intervention, focusing on comparative English-Czech writing conventions and domain-specific text analysis in a collaborative learning environment, aimed to enhance the students' self-efficacy. Findings demonstrated an increase in students' self-reported confidence and comfort. While grammatical accuracy is often present, structural and content-level challenges persist and are identified by the students. The intervention demonstrates the value of focused engagement with language use in a collaborative learning environment, informing pedagogical practices to improve academic writing instruction for STEM students and foster their professional development.