Research suggests that employers value various soft skills highly when recruiting software engineering (SE) graduates in the software industry; however, SE graduate students tend to lack those soft skills. This study examines the effects of a capstone course with a problem/project-based approach in the acquisition of soft skills. In this capstone, the graduate students worked closely on a real-world project with the customers from Finnish public and private organizations. Moreover, the study maps out the identified soft skills from the capstone course to the desired requirements of soft skills in various roles in the software industry. Thematic data analysis of reflections given by 48 students identified fifteen soft skill categories that are mainly acknowledged by the students after the completion of the course. In particular, we have shown that the majority of identified soft skills in this course correspond to the desirable soft skills in the software industry. To conclude, the approach taken in this course is a powerful means to improve the soft skills of the graduate students to meet the needs of employers, and thus increase their employment prospects.