Over the past few years, corruption has had a starring role in almost every discussion about good governance. The call for transparency has never been as loud and as clear as it is today. One way to keep government and its institutions accountable is through tracking its numbers, either through self-checks, by the public, or external organisations. The latter two checks only work only if the government opened more access to data. Open Data Day is on March 4 this year. To mark the day, we speak to Khairil Yusof, co-founder of the Sinar Project, about what the project does, why they do it, the stories that numbers and data sets can tell you, and how it helps keep the government accountable.