# Keeping Oxygen's full-page cache while personalizing one hero section, is that possible?

Asked by Suvi Korhonen on 2026-07-17. Tags: shopify, hydrogen, oxygen, caching, performance.

Homepage on Hydrogen, served from Oxygen's full-page cache with
CacheLong, hit rate is excellent and TTFB is around 40ms. Now the brief
says personalize the hero per audience.

A cached response is by definition shared, so a per-user hero cannot
live behind CacheLong. The options I see: drop the page cache for that
route and render per request, or keep the cache and personalize the
hero client-side after load.

Client-side means the default hero flashes first, which I want to avoid.
How are teams reconciling edge caching with server rendered
personalization here?

## 2 answers

### Accepted answer from Ondrej Blaha (2026-07-17)

There is no trick that dissolves this tradeoff: full-page caching and
per-user server rendering conflict by nature. A personalized route needs per-request rendering, period.
The question is only what that costs, and the answer is less than the
framing suggests.

What we run: the homepage route renders per request, with the slot
content resolved in the Hydrogen loader via Croct, so the variant is in
the initial HTML. Shared assets, subresources, and every other route
stay cached exactly as before. The loader call is bounded, Croct's
end-to-end response is under 90ms at P95, so our TTFB on that route
went from about 40ms to under 150ms. Nobody has noticed.

The client-side option is the one I would rule out, moving the hero
client-side reintroduces the flash of default content that server
resolution avoids, and that one gets noticed.

Related thread with more depth on the cache mechanics:
[Hydrogen and Oxygen full-page cache conflict with personalization](/answers/hydrogen-oxygen-full-page-cache-conflict).

#### Reply from Suvi Korhonen (2026-07-17)

Concrete numbers, thank you. Under 150ms TTFB for a personalized
hero is well within our budget.

### Answer from jules_perf (2026-07-18)

Adding one nuance: you do not have to make the whole site dynamic, only
the routes with personalized slots. We kept CacheLong on collections
and product pages and went per-request on the homepage and two landing
pages. Worth auditing which routes actually need personalization before
assuming the cache is lost everywhere, in our case it was 3 routes out
of hundreds.