diff --git a/src/api.js b/src/api.js
index 56b1950..5c382f6 100644
--- a/src/api.js
+++ b/src/api.js
@@ -48,16 +48,21 @@ const byNewest = (a, b) => b.sort - a.sort;
 
 const sidecarsFor = (key) => [key + ".sha256", key + ".sig"];
 
+// parts[0]=product, parts[1]=version (e.g., 2.1.0-rc), parts[2]=build (e.g., 8465201),
+// parts[3]=platform (windows|darwin|linux), parts[4]=arch (x86-64|aarch64)
 const parseName = (fname) => {
-  // Expected convention: parts[3] = platform (windows|darwin|linux), parts[4] = arch
   const parts = fname.split("_");
+  const product = parts[0] ?? "";
+  const version = parts[1] ?? "";
+  const build = parts[2] ?? "";
   const platform = (parts[3] ?? "").toLowerCase();
   const arch = parts[4] ?? "";
-  const groupId = `${parts[0] ?? ""}_${platform}_${arch}`;
-  return { parts, platform, arch, groupId };
+  const groupId = `${product}_${platform}_${arch}`; // retention groups
+  const releaseId = `${product}_${build}`; // emit grouping
+  return { parts, product, version, build, platform, arch, groupId, releaseId };
 };
 
-// Remove sidecar suffixes first, then packaging suffix to compute a common base across variants
+// Remove sidecar suffixes first, then packaging suffix
 const stripSidecar = (name) => {
   if (name.endsWith(".sha256")) return name.slice(0, -".sha256".length);
   if (name.endsWith(".sig")) return name.slice(0, -".sig".length);
@@ -77,6 +82,27 @@ const isTar = (name) => name.endsWith(TAR_EXT);
 const isDmg = (name) => name.endsWith(".dmg");
 const isSetup = (name) => name.endsWith("_setup.exe");
 
+// platform/arch sort preference inside a build
+const platformRank = (platform) =>
+  platform === "darwin"
+    ? 0
+    : platform === "windows"
+      ? 1
+      : platform === "linux"
+        ? 2
+        : 3;
+
+const archRank = (arch) =>
+  arch === "aarch64"
+    ? 0
+    : arch === "arm64"
+      ? 0 // normalize if needed later
+      : arch === "x86-64"
+        ? 1
+        : arch === "x86_64"
+          ? 1
+          : 2;
+
 /* ---------------- public API ---------------- */
 
 const cleanOldItems = async () => {
@@ -122,56 +148,72 @@ const getBucketFiles = async (folderName) => {
     const contents = (data.Contents ?? []).filter((it) => it.Key !== folderKey);
     const listed = contents.map(toListed(folderKey)).sort(byNewest);
 
-    // Build indexes
+    // Indexes
     const byKey = Object.fromEntries(listed.map((i) => [i.key, i]));
-    const byBase = new Map(); // base -> { tar, dmg, setup, sidecars:Set<string> }
+    const byBase = new Map(); // base -> { rep, tar, dmg, setup, sidecars:Set<string>, platform, arch, releaseId }
     for (const it of listed) {
       const base = baseStem(it.name);
       let g = byBase.get(base);
       if (!g) {
-        g = { tar: null, dmg: null, setup: null, sidecars: new Set() };
+        // We’ll fill platform/arch/releaseId from the *first* non-sidecar file we see
+        g = {
+          rep: null,
+          tar: null,
+          dmg: null,
+          setup: null,
+          sidecars: new Set(),
+          platform: "",
+          arch: "",
+          releaseId: "",
+        };
         byBase.set(base, g);
       }
       if (isTar(it.name)) {
         g.tar = it;
+        g.rep = g.rep ?? it;
+        const meta = parseName(it.name);
+        g.platform = meta.platform;
+        g.arch = meta.arch;
+        g.releaseId = meta.releaseId;
       } else if (isDmg(it.name)) {
         g.dmg = it;
+        g.rep = g.rep ?? it;
+        const meta = parseName(it.name);
+        if (!g.platform) g.platform = meta.platform;
+        if (!g.arch) g.arch = meta.arch;
+        if (!g.releaseId) g.releaseId = meta.releaseId;
       } else if (isSetup(it.name)) {
         g.setup = it;
+        g.rep = g.rep ?? it;
+        const meta = parseName(it.name);
+        if (!g.platform) g.platform = meta.platform;
+        if (!g.arch) g.arch = meta.arch;
+        if (!g.releaseId) g.releaseId = meta.releaseId;
       } else if (it.name.endsWith(".sha256") || it.name.endsWith(".sig")) {
         g.sidecars.add(it.key);
       }
     }
 
-    const groups = Array.from(byBase.values());
+    const groups = Array.from(byBase.values()).filter((g) => g.rep);
 
-    // Nightly retention: keep newest 3 per (name_platform_arch).
+    // ---------- Retention (unchanged logic): newest 3 per product+platform+arch ----------
     const keepBaseSet = new Set();
     if (folder === "nightly") {
-      const buckets = new Map(); // groupId -> array of group objects
+      const buckets = new Map(); // groupId -> [groups]
       for (const g of groups) {
-        const rep = g.tar ?? g.dmg ?? g.setup;
-        if (!rep) continue;
-        const { groupId } = parseName(rep.name);
-        if (!buckets.has(groupId)) buckets.set(groupId, []);
-        buckets.get(groupId).push(g);
+        const meta = parseName(g.rep.name);
+        const gid = meta.groupId;
+        if (!buckets.has(gid)) buckets.set(gid, []);
+        buckets.get(gid).push(g);
       }
-
       for (const [, arr] of buckets) {
-        arr.sort((a, b) => {
-          const ta = (a.tar ?? a.dmg ?? a.setup)?.sort ?? 0;
-          const tb = (b.tar ?? b.dmg ?? b.setup)?.sort ?? 0;
-          return tb - ta;
-        });
-
+        arr.sort((a, b) => (b.rep?.sort ?? 0) - (a.rep?.sort ?? 0));
         arr.forEach((g, idx) => {
-          const rep = g.tar ?? g.dmg ?? g.setup;
-          if (!rep) return;
-          const base = baseStem(rep.name);
+          const base = baseStem(g.rep.name);
           if (idx < 3) {
             keepBaseSet.add(base);
           } else {
-            // mark all artifacts in the group as old
+            // mark all artifacts in this base as old
             if (g.tar)
               [g.tar.key, ...sidecarsFor(g.tar.key)].forEach((k) =>
                 oldKeys.add(k),
@@ -188,49 +230,65 @@ const getBucketFiles = async (folderName) => {
         });
       }
     } else {
-      // keep all groups in non-nightly
       for (const g of groups) {
-        const rep = g.tar ?? g.dmg ?? g.setup;
-        if (rep) keepBaseSet.add(baseStem(rep.name));
+        keepBaseSet.add(baseStem(g.rep.name));
       }
     }
 
-    // Emit kept groups in newest-first order, using representative timestamp
-    const kept = groups
-      .filter((g) => {
-        const rep = g.tar ?? g.dmg ?? g.setup;
-        return rep && keepBaseSet.has(baseStem(rep.name));
-      })
-      .sort((a, b) => {
-        const ta = (a.tar ?? a.dmg ?? a.setup)?.sort ?? 0;
-        const tb = (b.tar ?? b.dmg ?? b.setup)?.sort ?? 0;
-        return tb - ta;
+    // ---------- Emit order: group KEPT bases by releaseId (build), newest-first by representative timestamp ----------
+    const kept = groups.filter((g) => keepBaseSet.has(baseStem(g.rep.name)));
+    const releases = new Map(); // releaseId -> { repSort:number, items: [g...] }
+    for (const g of kept) {
+      const rid = g.releaseId || parseName(g.rep.name).releaseId;
+      if (!releases.has(rid)) {
+        releases.set(rid, { repSort: g.rep.sort, items: [] });
+      }
+      const bucket = releases.get(rid);
+      bucket.repSort = Math.max(bucket.repSort, g.rep.sort);
+      bucket.items.push(g);
+    }
+
+    // sort releases newest-first
+    const releaseList = Array.from(releases.entries()).sort(
+      (a, b) => b[1].repSort - a[1].repSort,
+    );
+
+    // Inside each release, sort platforms/arches by preference
+    const out = [];
+    for (const [, bucket] of releaseList) {
+      bucket.items.sort((a, b) => {
+        const pr = platformRank(a.platform) - platformRank(b.platform);
+        if (pr !== 0) return pr;
+        const ar = archRank(a.arch) - archRank(b.arch);
+        if (ar !== 0) return ar;
+        // fallback: newest-first
+        return (b.rep?.sort ?? 0) - (a.rep?.sort ?? 0);
       });
 
-    const out = [];
-    for (const g of kept) {
-      // tar + sidecars
-      if (g.tar) {
-        out.push(g.tar);
-        for (const sk of sidecarsFor(g.tar.key)) {
-          const it = byKey[sk];
-          if (it) out.push(it);
+      for (const g of bucket.items) {
+        // tar + sidecars
+        if (g.tar) {
+          out.push(g.tar);
+          for (const sk of sidecarsFor(g.tar.key)) {
+            const it = byKey[sk];
+            if (it) out.push(it);
+          }
         }
-      }
-      // dmg + sidecars
-      if (g.dmg) {
-        out.push(g.dmg);
-        for (const sk of sidecarsFor(g.dmg.key)) {
-          const it = byKey[sk];
-          if (it) out.push(it);
+        // dmg + sidecars
+        if (g.dmg) {
+          out.push(g.dmg);
+          for (const sk of sidecarsFor(g.dmg.key)) {
+            const it = byKey[sk];
+            if (it) out.push(it);
+          }
         }
-      }
-      // setup + sidecars
-      if (g.setup) {
-        out.push(g.setup);
-        for (const sk of sidecarsFor(g.setup.key)) {
-          const it = byKey[sk];
-          if (it) out.push(it);
+        // setup + sidecars
+        if (g.setup) {
+          out.push(g.setup);
+          for (const sk of sidecarsFor(g.setup.key)) {
+            const it = byKey[sk];
+            if (it) out.push(it);
+          }
         }
       }
     }