'Measure twice, cut once.' The move from waterfall to agile replaced 6–18 months of up-front design, but the community has over-corrected to being uncomfortable with more than 6–18 minutes of design. A week of designing one service (followed by a week or two of implementation) is not waterfall; the first such week will feel painful to people unused to designing, but it's the fundamental philosophy needed to succeed in event-sourced/service systems.