diff --git a/internal/tender/ai_reference_test.go b/internal/tender/ai_reference_test.go
index 7dfc6ae..76c1ce6 100644
--- a/internal/tender/ai_reference_test.go
+++ b/internal/tender/ai_reference_test.go
@@ -1,6 +1,10 @@
 package tender
 
-import "testing"
+import (
+	"testing"
+
+	"go.mongodb.org/mongo-driver/v2/bson"
+)
 
 func TestParseAIProcedureRef(t *testing.T) {
 	tests := []struct {
@@ -84,3 +88,37 @@ func TestMapProcedureReferencesToTenders(t *testing.T) {
 		t.Fatalf("expected folder-2 ref to resolve, got %+v", got["PROC_folder-2/notice-2"])
 	}
 }
+
+func TestMapProcedureReferencesToTendersUsesFolderCandidatesWhenNoticeLookupMisses(t *testing.T) {
+	// Notice-old is only present on the merged tender loaded via contract_folder_id.
+	candidates := []Tender{
+		{
+			ContractFolderID:            "folder-1",
+			NoticePublicationID:         "notice-new",
+			RelatedNoticePublicationIDs: []string{"notice-old"},
+		},
+	}
+	refs := []ProcedureReference{
+		{Ref: "PROC_folder-1/notice-old", ContractFolderID: "folder-1", NoticePublicationID: "notice-old"},
+	}
+
+	got := mapProcedureReferencesToTenders(candidates, refs)
+	if len(got) != 1 {
+		t.Fatalf("mapProcedureReferencesToTenders() len = %d, want 1", len(got))
+	}
+	if got["PROC_folder-1/notice-old"].NoticePublicationID != "notice-new" {
+		t.Fatalf("expected folder candidate to resolve notice-old ref, got %+v", got["PROC_folder-1/notice-old"])
+	}
+}
+
+func TestMergeTenderCandidatesDedupesByMongoID(t *testing.T) {
+	first := Tender{ContractFolderID: "folder-1", NoticePublicationID: "notice-a"}
+	first.ID, _ = bson.ObjectIDFromHex("507f1f77bcf86cd799439011")
+	second := Tender{ContractFolderID: "folder-1", NoticePublicationID: "notice-b"}
+	second.ID = first.ID
+
+	got := mergeTenderCandidates([]Tender{first}, []Tender{second})
+	if len(got) != 1 {
+		t.Fatalf("mergeTenderCandidates() len = %d, want 1", len(got))
+	}
+}
diff --git a/internal/tender/recommendation_filter.go b/internal/tender/recommendation_filter.go
index b6c2ed7..7483149 100644
--- a/internal/tender/recommendation_filter.go
+++ b/internal/tender/recommendation_filter.go
@@ -97,19 +97,22 @@ func addTenderIDsToSet(set map[string]struct{}, ids []string) {
 // markResolvedRecommendedTenderSeen records a resolved tender and reports whether it was already seen.
 // Recommendations may reference the same tender via different AI refs (procedure ref vs Mongo ID,
 // or multiple notice publication IDs for one merged tender).
-func markResolvedRecommendedTenderSeen(seen map[string]struct{}, tender Tender) bool {
+func markResolvedRecommendedTenderSeen(seen map[string]struct{}, tender Tender, tenderRef string) bool {
 	if seen == nil {
 		return false
 	}
 
-	tenderID := strings.TrimSpace(tender.GetID())
-	if tenderID == "" {
+	key := strings.TrimSpace(tender.GetID())
+	if key == "" {
+		key = strings.TrimSpace(tenderRef)
+	}
+	if key == "" {
+		return false
+	}
+	if _, exists := seen[key]; exists {
 		return true
 	}
-	if _, exists := seen[tenderID]; exists {
-		return true
-	}
-	seen[tenderID] = struct{}{}
+	seen[key] = struct{}{}
 	return false
 }
 
diff --git a/internal/tender/recommendation_filter_test.go b/internal/tender/recommendation_filter_test.go
index 0f16e65..1576357 100644
--- a/internal/tender/recommendation_filter_test.go
+++ b/internal/tender/recommendation_filter_test.go
@@ -132,8 +132,8 @@ func TestMarkResolvedRecommendedTenderSeen(t *testing.T) {
 	sample.ID, _ = bson.ObjectIDFromHex("507f1f77bcf86cd799439011")
 
 	seen := make(map[string]struct{})
-	first := markResolvedRecommendedTenderSeen(seen, sample)
-	second := markResolvedRecommendedTenderSeen(seen, sample)
+	first := markResolvedRecommendedTenderSeen(seen, sample, "PROC_folder/notice")
+	second := markResolvedRecommendedTenderSeen(seen, sample, "PROC_folder/notice")
 	if first {
 		t.Fatalf("first sighting should not be skipped, id=%q seen=%v", sample.GetID(), seen)
 	}
@@ -143,7 +143,7 @@ func TestMarkResolvedRecommendedTenderSeen(t *testing.T) {
 
 	otherRefSameTender := Tender{}
 	otherRefSameTender.ID = sample.ID
-	if !markResolvedRecommendedTenderSeen(seen, otherRefSameTender) {
+	if !markResolvedRecommendedTenderSeen(seen, otherRefSameTender, "PROC_folder/other-notice") {
 		t.Fatalf("duplicate tender via different ref should be skipped")
 	}
 }
diff --git a/internal/tender/recommendation_page.go b/internal/tender/recommendation_page.go
index 2695e41..60f5340 100644
--- a/internal/tender/recommendation_page.go
+++ b/internal/tender/recommendation_page.go
@@ -69,7 +69,7 @@ func (s *tenderService) buildRecommendationPage(
 			if len(form.Status) > 0 && !statusAllowed(tender.Status, form.Status) {
 				continue
 			}
-			if markResolvedRecommendedTenderSeen(seenTenderIDs, tender) {
+			if markResolvedRecommendedTenderSeen(seenTenderIDs, tender, tenderRef) {
 				continue
 			}
 
diff --git a/internal/tender/repository.go b/internal/tender/repository.go
index 8c5dca8..3987164 100644
--- a/internal/tender/repository.go
+++ b/internal/tender/repository.go
@@ -362,13 +362,18 @@ func (r *tenderRepository) GetByProcedureReference(ctx context.Context, contract
 
 const procedureReferenceLookupBatchSize = 250
 
-// GetByProcedureReferences loads tenders for multiple AI procedure refs using indexed notice lookups.
+const contractFolderLookupBatchSize = 250
+
+// GetByProcedureReferences loads tenders for multiple AI procedure refs.
+// It combines indexed notice lookups with contract-folder candidates so older notice
+// references still resolve after tender merges (same behavior as before the perf refactor).
 func (r *tenderRepository) GetByProcedureReferences(ctx context.Context, refs []ProcedureReference) (map[string]Tender, error) {
 	out := make(map[string]Tender)
 	if len(refs) == 0 {
 		return out, nil
 	}
 
+	folderIDs := make([]string, 0, len(refs))
 	noticeIDs := make([]string, 0, len(refs))
 	for _, ref := range refs {
 		folder := strings.TrimSpace(ref.ContractFolderID)
@@ -376,15 +381,12 @@ func (r *tenderRepository) GetByProcedureReferences(ctx context.Context, refs []
 		if folder == "" || notice == "" {
 			continue
 		}
+		folderIDs = append(folderIDs, folder)
 		noticeIDs = append(noticeIDs, notice)
 	}
 
 	uniqueNotices := uniqueNonEmptyTrimmedStrings(noticeIDs)
-	if len(uniqueNotices) == 0 {
-		return out, nil
-	}
-
-	candidates := make([]Tender, 0, len(uniqueNotices))
+	noticeCandidates := make([]Tender, 0, len(uniqueNotices))
 	for start := 0; start < len(uniqueNotices); start += procedureReferenceLookupBatchSize {
 		end := start + procedureReferenceLookupBatchSize
 		if end > len(uniqueNotices) {
@@ -395,12 +397,79 @@ func (r *tenderRepository) GetByProcedureReferences(ctx context.Context, refs []
 		if err != nil {
 			return nil, err
 		}
-		candidates = append(candidates, batch...)
+		noticeCandidates = append(noticeCandidates, batch...)
 	}
 
+	folderCandidates, err := r.findTendersByContractFolderIDs(ctx, folderIDs)
+	if err != nil {
+		return nil, err
+	}
+
+	candidates := mergeTenderCandidates(noticeCandidates, folderCandidates)
 	return mapProcedureReferencesToTenders(candidates, refs), nil
 }
 
+func (r *tenderRepository) findTendersByContractFolderIDs(ctx context.Context, folderIDs []string) ([]Tender, error) {
+	uniqueFolders := uniqueNonEmptyTrimmedStrings(folderIDs)
+	if len(uniqueFolders) == 0 {
+		return nil, nil
+	}
+
+	out := make([]Tender, 0, len(uniqueFolders))
+	for start := 0; start < len(uniqueFolders); start += contractFolderLookupBatchSize {
+		end := start + contractFolderLookupBatchSize
+		if end > len(uniqueFolders) {
+			end = len(uniqueFolders)
+		}
+		batch := uniqueFolders[start:end]
+
+		findLimit := len(batch) * 5
+		if minLimit := len(batch) + 1; findLimit < minLimit {
+			findLimit = minLimit
+		}
+
+		filter := bson.M{"contract_folder_id": bson.M{"$in": batch}}
+		pagination := orm.Pagination{
+			Limit:     findLimit,
+			SortField: "updated_at",
+			SortOrder: -1,
+			SkipCount: true,
+		}
+
+		result, err := r.ormRepo.FindAll(ctx, filter, pagination)
+		if err != nil {
+			r.logger.Error("Failed to get tenders by contract folder IDs", map[string]interface{}{
+				"count": len(batch),
+				"error": err.Error(),
+			})
+			return nil, err
+		}
+		out = append(out, result.Items...)
+	}
+
+	return out, nil
+}
+
+func mergeTenderCandidates(groups ...[]Tender) []Tender {
+	seen := make(map[string]struct{})
+	out := make([]Tender, 0)
+	for _, group := range groups {
+		for i := range group {
+			tenderID := strings.TrimSpace(group[i].GetID())
+			if tenderID == "" {
+				out = append(out, group[i])
+				continue
+			}
+			if _, exists := seen[tenderID]; exists {
+				continue
+			}
+			seen[tenderID] = struct{}{}
+			out = append(out, group[i])
+		}
+	}
+	return out
+}
+
 func (r *tenderRepository) findTendersByNoticePublicationIDs(ctx context.Context, noticeIDs []string) ([]Tender, error) {
 	if len(noticeIDs) == 0 {
 		return nil, nil
@@ -413,7 +482,7 @@ func (r *tenderRepository) findTendersByNoticePublicationIDs(ctx context.Context
 		},
 	}
 	pagination := orm.Pagination{
-		Limit:     len(noticeIDs) * 2,
+		Limit:     len(noticeIDs) * 3,
 		SortField: "updated_at",
 		SortOrder: -1,
 		SkipCount: true,