<p>Among the countries of the Organisation for Economic Co-operation and Development (OECD), Hungary consistently ranks in the bottom 10 per cent in terms of the correlation between sociocultural background and school performance. Not only do cumulatively disadvantaged students perform below average, but their academic lag worsens with age, contributing to higher drop-out rates and trapping them in a low social and economic status. There is a strong correlation between disadvantage and belonging to the Roma minority in Hungary. Despite attempts to reduce the marginalization of Roma youth, a third of Roma students receive education in a highly segregated environment. In regions where most students’ knowledge falls below the minimum age-appropriate level, specialized catch-up methods are required. In September 2021, we initiated a comprehensive catch-up programme at a high school predominantly attended by Roma students. This study analyses the experiences of the first two years, focusing on the progress of ninth graders in mathematics and informatics. We developed an unsupervised practice method utilizing the Edubase online educational platform. The platform generates parameterized tests from a given subtopic, provides immediate feedback, and allows the student to retake newly generated tests as they see fit. It was found that using this method fostered interaction and emerging teaching situations among the students. It also developed their computer skills and improved their ability to focus for longer. The article provides a qualitative and quantitative analysis of these effects, based on the data from the test and interviews with students and teachers.</p>