From ecb9f67c990c6ec3fbdc430825dd25502901f310 Mon Sep 17 00:00:00 2001
From: saravanakumardb1 <saravanakumardb1@users.noreply.github.com>
Date: Mon, 2 Mar 2026 23:56:42 -0800
Subject: [PATCH] fix(broadcasts): Fix percentage rollout bucketing logic

- Use userId only as seed instead of userId + percentage
- Prevents users from being re-bucketed when rollout % increases
- Ensures deterministic assignment for phased rollouts
---
 .../platform-service/src/modules/broadcasts/targeting.ts     | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/services/platform-service/src/modules/broadcasts/targeting.ts b/services/platform-service/src/modules/broadcasts/targeting.ts
index c724463d..a6655632 100644
--- a/services/platform-service/src/modules/broadcasts/targeting.ts
+++ b/services/platform-service/src/modules/broadcasts/targeting.ts
@@ -79,8 +79,9 @@ export function evaluateTarget(
 
   // Percentage rollout (FNV-1a hash for deterministic bucketing)
   if (target.percentageRollout !== undefined && target.percentageRollout < 100) {
-    // Hash userId + broadcast seed for consistent assignment
-    const hash = fnv1a32(`${context.userId}:${target.percentageRollout}`);
+    // Use userId only as seed for consistent bucketing
+    // This ensures when rollout % increases, same users stay included
+    const hash = fnv1a32(context.userId);
     const bucket = hash % 100;
     if (bucket >= target.percentageRollout) {
       return false;