# Roblox puts creative-ad pre-ranking system into production

> A new system shortlists ad creatives before user-level ranking. Roblox says it is live after an A/B test, with replay tests showing fewer creatives forwarded and little added serving time.

Oossa · 2026-10-28 · https://oossa.com/en/roblox-puts-creative-ad-pre-ranking-system-into-production

Researchers describe a system Roblox now uses to shortlist which ad creatives move on to its per-user ad ranking step. It estimates performance using data shared across audience segments, items, campaigns and creatives, so a new creative can draw on information from its parent groups. A single randomized score gives less-tested creatives a chance to be selected and learned about.

In a replay of Roblox Sponsored Ads traffic, the shortlist raised predicted play-through rate by 8.14%, compared with 2.80% for an equally sized random shortlist. The researchers say it forwarded more than 40% fewer creatives than the full pool and added 0.2% to serving time; the paper also says Roblox deployed it after a live A/B test.

## The facts

- The reported replay showed an 8.14% lift in predicted play-through rate, versus 2.80% for a random shortlist of equal size.
- The system forwards more than 40% fewer creatives than the full pool and adds 0.2% to serving time, according to the researchers.

## Why it matters

For Roblox advertisers, the system may help newer ads get tested while reducing the number of creatives sent to later ranking; the paper does not report the live A/B test's results.

## Sources & references

1. [Exploratory creative pre-ranking: Hierarchical empirical-Bayes Thompson sampling for real-time creative optimization](https://arxiv.org/abs/2610.36020) – arXiv cs.LG, 2026-10-28

Last updated: 2026-10-28