This article explored the impact of strategies applied in a mathematics instructional technology course for developing technology integration competencies, in particular in the use of spreadsheets, in pre-service teachers. In this respect, 104 pre-service mathematics teachers from a teacher training programme in Ghana enrolled in the mathematics instructional technology course for one semester. Strategies applied in designing the course were: aligning theory and practice, collaborative design, learning technology by design, modelling how to use technology and scaffolding authentic technology experiences. The pre-service teachers' technology integration competencies were assessed through analysis of lesson plans and lesson observations, their self-reported technological pedagogical content knowledge and attitudes towards technology. Findings show that pre-service teachers' technology integration competencies improved after participation in the course. All strategies were considered important, but in particular, scaffolding authentic technology experiences including feedback from teaching try-outs made significant contributions to the pre-service teachers' developed technology integration competencies. The study provides guidelines that can serve as a benchmark for implementing strategies in the design of a subject-specific teacher education programme in preparing pre-service teachers to integrate technology in teaching.