The cognitive load problem compounds when you're wearing multiple hats. As a solo founder, you're context-switching between code, support tickets, billing issues, and marketing — all within the same hour. Each switch taxes your working memory and the quality of each task drops.
Something that helped me: batching similar tasks into dedicated time blocks. All code in the morning when focus is highest, all communication in the afternoon. It sounds basic, but the reduction in mental switching cost is massive.
The other underrated lever: making things deletable rather than configurable. Every config option you add is permanent cognitive load for future-you. Sometimes the best architecture decision is fewer choices.