react: Page 1

02 POSTS

React 1

#react#state-management#tanstack-query
Is React Query's staleTime: 0 really 0? And why?
I prefetched the data and even hydrated it, and queryFn was still called twice. In the last post I explained that as staleTime being 0, and the explanation was not right. In Suspense mode staleTime is clamped to a minimum of 1,000ms. I followed React Query and React internals to find out why that floor is needed, where the gap is measured, and what pushed my experiment past one second. The key was that a suspended render leaves nothing behind. And even with the same code, the time that passes changes with the environment it runs in.
2026-10-03Updated 2026-10-1225 min read
◆ Rendering Boundaries · Part 1
#react#nextjs#debugging
Rendering Boundaries[1]: Server Functions cannot be called during initial render
I traced an error that was piling up in DataDog at about 3,000 a week. The cause was that useSuspenseQuery runs queryFn during render, before commit, and a Server Function was sitting inside it. Instead of the advice to switch to useQuery, I pulled the read function out of the use server file and the error went to zero. But when I measured 30 runs in the same sandbox, the requests came back as 60. The server and the browser have different queryClients.
2026-10-0115 min read