Small and medium-sized enterprises (SMEs) play a key role in the worldwide economy and are increasingly dependent on software as part of their products/services or to support their operation (e.g. e-commerce, smart manufacturing). Over the past 15 years, as a research and technology transfer centre, CETIC has been busy helping Belgian SMEs to increase their maturity in software development. We have also contributed specifc methods and tools for the SME target, including the OWPL framework and now the ISO29110 standard. This talk aims at sharing what we learned from different types of SMEs (from startups to grownups, both IT and non IT) about common problems gathered in a long term survey. We then focus on key issues like requirements, technical debt, test/release and (agile/lean) project management. Finally, we share our thoughts on new challenges ahead raised by the ever increasing connectivity like cybersecurity and privacy regulation (GDPR).