On 11 May 2021, Estonia’s Ministry of Social Affairs unexpectedly announced that Covid-19 vaccinations would be opened to all Estonians over 16 years old – 500,000 people – in just one week’s time. Estonia’s Chief Information Officer (CIO) Siim Sikkut worried that this large influx of users would crash the repurposed digital health portal. However, he did not have direct authority over the digital decisions of the social affairs ministry. What, if anything, could he do to prevent a crash?