Until 2018, most German organisations refused categorically to migrate systems with valuable business data to public cloud. But things have changed, and public cloud is "strategic". But especially if it comes to big data architectures, the tempting cost advantages are not obvious. We enlight some common-sense questions like:

• Why is the migration of my big data solution expensive, although even small big data startups can afford to run in public cloud?
• Is the attack surface of my data repository really larger in public cloud?
• Can and should I use platform services, or do I have to avoid vendor lock-in at any price?
• Can automation help me to get more cloud-independent?

The questions are addressed along the journey with a real world customer – with a surprising (happy?) end.