That's a bit of a different meaning than the original martial arts thinking. The end of the first follow (shu) part is where the technique is crisp, distinct,

That's a bit of a different meaning than the original martial arts thinking. The end of the first follow (shu) part is where the technique is crisp, distinct, and "right". After that comes pragmatic application (ha) and finally improvisation (ri), which both generally lead to "less right" but more workable technique. shu = implement B+tree following a guide, long struggle to get it correct, also learn about testing etc tangentially related topics ha = optimize B+tree using learnings from other various data structures, explore alternatives like LSM/HAMT/etc, use what works, develop understanding of the differences ri = invent B-epsilon trees yourself