diff --git a/defects/ipfs-cluster-0001/patch/ipfs-cluster-0001.patch b/defects/ipfs-cluster-0001/patch/ipfs-cluster-0001.patch
new file mode 100644
index 000000000..610081953
--- /dev/null
+++ b/defects/ipfs-cluster-0001/patch/ipfs-cluster-0001.patch
@@ -0,0 +1,61 @@
+--- a/allocate.go
++++ b/allocate.go
+@@ -123,11 +123,22 @@ func (c *Cluster) filterMetrics(ctx context.Context, mSet api.MetricsSet, numMet
+ // For a metric/peer to be included in a group, it is necessary that it has
+ // metrics for all informers.
+ func (c *Cluster) filterMetrics(ctx context.Context, mSet api.MetricsSet, numMetrics int, currentAllocs, priorityList, blacklist []peer.ID) classifiedMetrics {
+ 	curPeersMap := make(map[peer.ID][]api.Metric)
+ 	candPeersMap := make(map[peer.ID][]api.Metric)
+ 	prioPeersMap := make(map[peer.ID][]api.Metric)
+
+-	// Divide the metric by current/candidate/prio and by peer
++	// Build O(1) lookup sets for peer classification.
++	blacklistSet := make(map[peer.ID]struct{}, len(blacklist))
++	for _, p := range blacklist {
++		blacklistSet[p] = struct{}{}
++	}
++	currentAllocsSet := make(map[peer.ID]struct{}, len(currentAllocs))
++	for _, p := range currentAllocs {
++		currentAllocsSet[p] = struct{}{}
++	}
++	prioritySet := make(map[peer.ID]struct{}, len(priorityList))
++	for _, p := range priorityList {
++		prioritySet[p] = struct{}{}
++	}
++
++	// Divide our metrics by current/candidate/prio and by peer
+ 	for _, metrics := range mSet {
+ 		for _, m := range metrics {
+ 			switch {
+-			case containsPeer(blacklist, m.Peer):
++			case peerInSet(blacklistSet, m.Peer):
+ 				// discard blacklisted peers
+ 				continue
+ 			case c.config.PinOnlyOnTrustedPeers && !c.consensus.IsTrustedPeer(ctx, m.Peer):
+@@ -136,9 +147,9 @@ func (c *Cluster) filterMetrics(ctx context.Context, mSet api.MetricsSet, numMet
+ 			case c.config.PinOnlyOnUntrustedPeers && c.consensus.IsTrustedPeer(ctx, m.Peer):
+ 				// discard peers that are trusted
+ 				continue
+-			case containsPeer(currentAllocs, m.Peer):
++			case peerInSet(currentAllocsSet, m.Peer):
+ 				curPeersMap[m.Peer] = append(curPeersMap[m.Peer], m)
+-			case containsPeer(priorityList, m.Peer):
++			case peerInSet(prioritySet, m.Peer):
+ 				prioPeersMap[m.Peer] = append(prioPeersMap[m.Peer], m)
+ 			default:
+ 				candPeersMap[m.Peer] = append(candPeersMap[m.Peer], m)
+--- a/util.go
++++ b/util.go
+@@ -72,6 +72,12 @@ func containsPeer(list []peer.ID, peer peer.ID) bool {
+ 	return false
+ }
+
++// peerInSet checks for peer membership in a pre-built set. O(1) average.
++func peerInSet(set map[peer.ID]struct{}, p peer.ID) bool {
++	_, ok := set[p]
++	return ok
++}
++
+ func minInt(x, y int) int {
+ 	if x < y {
+ 		return x
diff --git a/defects/ipfs-cluster-0001/test/go.mod b/defects/ipfs-cluster-0001/test/go.mod
new file mode 100644
index 000000000..2eaaa411c
--- /dev/null
+++ b/defects/ipfs-cluster-0001/test/go.mod
@@ -0,0 +1,3 @@
+module ipfscluster0001
+
+go 1.21
diff --git a/defects/ipfs-cluster-0001/test/ipfs_cluster_0001_test.go b/defects/ipfs-cluster-0001/test/ipfs_cluster_0001_test.go
new file mode 100644
index 000000000..528d45a61
--- /dev/null
+++ b/defects/ipfs-cluster-0001/test/ipfs_cluster_0001_test.go
@@ -0,0 +1,158 @@
+package ipfscluster0001
+
+// Unit test for ipfs-cluster-0001: filterMetrics containsPeer O(N²)
+//
+// Defect: filterMetrics() calls containsPeer() (linear scan) for blacklist,
+// currentAllocs, and priorityList on every metric in our nested loop.
+// Complexity: O(M * (B + C + P)) where M = total metrics, B/C/P = list sizes.
+//
+// Fix: Convert slices to map[string]struct{} sets before our loop.
+// Patched complexity: O(M + B + C + P).
+
+import (
+	"fmt"
+	"testing"
+)
+
+// Simulates our peer.ID as a string (same underlying type in libp2p).
+type peerID string
+
+// --- BEFORE: linear scan (defective) ---
+
+func containsPeer(list []peerID, peer peerID) bool {
+	for _, p := range list {
+		if p == peer {
+			return true
+		}
+	}
+	return false
+}
+
+func filterMetricsBefore(
+	metrics []peerID,
+	blacklist []peerID,
+	currentAllocs []peerID,
+	priorityList []peerID,
+) (cur, prio, cand []peerID) {
+	for _, m := range metrics {
+		switch {
+		case containsPeer(blacklist, m):
+			continue
+		case containsPeer(currentAllocs, m):
+			cur = append(cur, m)
+		case containsPeer(priorityList, m):
+			prio = append(prio, m)
+		default:
+			cand = append(cand, m)
+		}
+	}
+	return
+}
+
+// --- AFTER: set lookup (patched) ---
+
+func peerInSet(set map[peerID]struct{}, p peerID) bool {
+	_, ok := set[p]
+	return ok
+}
+
+func toSet(list []peerID) map[peerID]struct{} {
+	s := make(map[peerID]struct{}, len(list))
+	for _, p := range list {
+		s[p] = struct{}{}
+	}
+	return s
+}
+
+func filterMetricsAfter(
+	metrics []peerID,
+	blacklist []peerID,
+	currentAllocs []peerID,
+	priorityList []peerID,
+) (cur, prio, cand []peerID) {
+	blacklistSet := toSet(blacklist)
+	currentAllocsSet := toSet(currentAllocs)
+	prioritySet := toSet(priorityList)
+
+	for _, m := range metrics {
+		switch {
+		case peerInSet(blacklistSet, m):
+			continue
+		case peerInSet(currentAllocsSet, m):
+			cur = append(cur, m)
+		case peerInSet(prioritySet, m):
+			prio = append(prio, m)
+		default:
+			cand = append(cand, m)
+		}
+	}
+	return
+}
+
+// --- Correctness ---
+
+func TestCorrectness(t *testing.T) {
+	metrics := []peerID{"p1", "p2", "p3", "p4", "p5", "p6"}
+	blacklist := []peerID{"p1"}
+	currentAllocs := []peerID{"p2", "p3"}
+	priorityList := []peerID{"p4"}
+
+	curB, prioB, candB := filterMetricsBefore(metrics, blacklist, currentAllocs, priorityList)
+	curA, prioA, candA := filterMetricsAfter(metrics, blacklist, currentAllocs, priorityList)
+
+	if fmt.Sprint(curB) != fmt.Sprint(curA) {
+		t.Fatalf("current mismatch: before=%v after=%v", curB, curA)
+	}
+	if fmt.Sprint(prioB) != fmt.Sprint(prioA) {
+		t.Fatalf("priority mismatch: before=%v after=%v", prioB, prioA)
+	}
+	if fmt.Sprint(candB) != fmt.Sprint(candA) {
+		t.Fatalf("candidate mismatch: before=%v after=%v", candB, candA)
+	}
+
+	// Verify expected classification
+	if fmt.Sprint(curA) != "[p2 p3]" {
+		t.Fatalf("expected cur=[p2 p3], got %v", curA)
+	}
+	if fmt.Sprint(prioA) != "[p4]" {
+		t.Fatalf("expected prio=[p4], got %v", prioA)
+	}
+	if fmt.Sprint(candA) != "[p5 p6]" {
+		t.Fatalf("expected cand=[p5 p6], got %v", candA)
+	}
+}
+
+// --- Benchmarks ---
+
+func makePeers(n int, prefix string) []peerID {
+	peers := make([]peerID, n)
+	for i := 0; i < n; i++ {
+		peers[i] = peerID(fmt.Sprintf("%s-%d", prefix, i))
+	}
+	return peers
+}
+
+func BenchmarkBefore(b *testing.B) {
+	// 500 metrics, 100 blacklisted, 100 current, 100 priority, 200 candidates
+	metrics := makePeers(500, "m")
+	blacklist := makePeers(100, "m")  // first 100 overlap
+	current := makePeers(100, "cur")
+	priority := makePeers(100, "pri")
+
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		filterMetricsBefore(metrics, blacklist, current, priority)
+	}
+}
+
+func BenchmarkAfter(b *testing.B) {
+	metrics := makePeers(500, "m")
+	blacklist := makePeers(100, "m")
+	current := makePeers(100, "cur")
+	priority := makePeers(100, "pri")
+
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		filterMetricsAfter(metrics, blacklist, current, priority)
+	}
+}