diff --git a/backend_go/Dockerfile b/backend_go/Dockerfile
index 9754d25..f71fe82 100644
--- a/backend_go/Dockerfile
+++ b/backend_go/Dockerfile
@@ -1,4 +1,5 @@
-FROM golang:1.22-alpine AS builder
+ARG GO_VERSION=1.24
+FROM golang:${GO_VERSION}-alpine AS builder
 
 WORKDIR /src
 
diff --git a/backend_go/graph_export.go b/backend_go/graph_export.go
index 2c676d9..4fc980f 100644
--- a/backend_go/graph_export.go
+++ b/backend_go/graph_export.go
@@ -15,10 +15,10 @@ func graphFromSparqlBindings(
 	nodeLimit int,
 	includeBNodes bool,
 ) (nodes []Node, edges []Edge) {
-	nodeIDByKey := map[termKey]int{}
+	nodeIDByKey := map[termKey]uint32{}
 	nodeMeta := make([]termMeta, 0, min(nodeLimit, 4096))
 
-	getOrAdd := func(term sparqlTerm) (int, bool) {
+	getOrAdd := func(term sparqlTerm) (uint32, bool) {
 		if term.Type == "" || term.Value == "" {
 			return 0, false
 		}
@@ -46,7 +46,7 @@ func graphFromSparqlBindings(
 		if len(nodeMeta) >= nodeLimit {
 			return 0, false
 		}
-		nid := len(nodeMeta)
+		nid := uint32(len(nodeMeta))
 		nodeIDByKey[key] = nid
 		nodeMeta = append(nodeMeta, meta)
 		return nid, true
@@ -78,7 +78,7 @@ func graphFromSparqlBindings(
 	nodes = make([]Node, len(nodeMeta))
 	for i, m := range nodeMeta {
 		nodes[i] = Node{
-			ID:       i,
+			ID:       uint32(i),
 			TermType: m.termType,
 			IRI:      m.iri,
 			Label:    nil,
diff --git a/backend_go/graph_snapshot.go b/backend_go/graph_snapshot.go
index 3048dfa..6f3b3f3 100644
--- a/backend_go/graph_snapshot.go
+++ b/backend_go/graph_snapshot.go
@@ -40,7 +40,7 @@ func fetchGraphSnapshot(
 	// Layout: invert edges for hierarchy (target -> source).
 	hierEdges := make([][2]int, 0, len(edges))
 	for _, e := range edges {
-		hierEdges = append(hierEdges, [2]int{e.Target, e.Source})
+		hierEdges = append(hierEdges, [2]int{int(e.Target), int(e.Source)})
 	}
 
 	layers, cycleErr := levelSynchronousKahnLayers(len(nodes), hierEdges)
diff --git a/backend_go/models.go b/backend_go/models.go
index 69ce343..2abd658 100644
--- a/backend_go/models.go
+++ b/backend_go/models.go
@@ -9,7 +9,7 @@ type HealthResponse struct {
 }
 
 type Node struct {
-	ID       int     `json:"id"`
+	ID       uint32  `json:"id"`
 	TermType string  `json:"termType"` // "uri" | "bnode"
 	IRI      string  `json:"iri"`
 	Label    *string `json:"label"`
@@ -18,8 +18,8 @@ type Node struct {
 }
 
 type Edge struct {
-	Source    int    `json:"source"`
-	Target    int    `json:"target"`
+	Source    uint32 `json:"source"`
+	Target    uint32 `json:"target"`
 	Predicate string `json:"predicate"`
 }
 
@@ -55,27 +55,27 @@ type SparqlQueryRequest struct {
 }
 
 type NeighborsRequest struct {
-	SelectedIDs []int `json:"selected_ids"`
-	NodeLimit   *int  `json:"node_limit,omitempty"`
-	EdgeLimit   *int  `json:"edge_limit,omitempty"`
-	GraphQueryID *string `json:"graph_query_id,omitempty"`
+	SelectedIDs  []uint32 `json:"selected_ids"`
+	NodeLimit    *int     `json:"node_limit,omitempty"`
+	EdgeLimit    *int     `json:"edge_limit,omitempty"`
+	GraphQueryID  *string `json:"graph_query_id,omitempty"`
 }
 
 type NeighborsResponse struct {
-	SelectedIDs []int `json:"selected_ids"`
-	NeighborIDs []int `json:"neighbor_ids"`
+	SelectedIDs []uint32 `json:"selected_ids"`
+	NeighborIDs []uint32 `json:"neighbor_ids"`
 }
 
 type SelectionQueryRequest struct {
-	QueryID     string `json:"query_id"`
-	SelectedIDs []int  `json:"selected_ids"`
-	NodeLimit   *int   `json:"node_limit,omitempty"`
-	EdgeLimit   *int   `json:"edge_limit,omitempty"`
-	GraphQueryID *string `json:"graph_query_id,omitempty"`
+	QueryID      string   `json:"query_id"`
+	SelectedIDs  []uint32 `json:"selected_ids"`
+	NodeLimit    *int     `json:"node_limit,omitempty"`
+	EdgeLimit    *int     `json:"edge_limit,omitempty"`
+	GraphQueryID  *string `json:"graph_query_id,omitempty"`
 }
 
 type SelectionQueryResponse struct {
-	QueryID     string `json:"query_id"`
-	SelectedIDs []int  `json:"selected_ids"`
-	NeighborIDs []int  `json:"neighbor_ids"`
+	QueryID     string   `json:"query_id"`
+	SelectedIDs []uint32 `json:"selected_ids"`
+	NeighborIDs []uint32 `json:"neighbor_ids"`
 }
diff --git a/backend_go/selection_queries/helpers.go b/backend_go/selection_queries/helpers.go
index 89916b3..4563cde 100644
--- a/backend_go/selection_queries/helpers.go
+++ b/backend_go/selection_queries/helpers.go
@@ -49,9 +49,9 @@ func termKeyFromSparqlTerm(term sparqlTerm, includeBNodes bool) (string, bool) {
 	return "", false
 }
 
-func selectedNodesFromIDs(idx Index, selectedIDs []int, includeBNodes bool) ([]NodeRef, map[int]struct{}) {
+func selectedNodesFromIDs(idx Index, selectedIDs []uint32, includeBNodes bool) ([]NodeRef, map[uint32]struct{}) {
 	out := make([]NodeRef, 0, len(selectedIDs))
-	set := make(map[int]struct{}, len(selectedIDs))
+	set := make(map[uint32]struct{}, len(selectedIDs))
 	for _, nid := range selectedIDs {
 		n, ok := idx.IDToNode[nid]
 		if !ok {
@@ -66,13 +66,13 @@ func selectedNodesFromIDs(idx Index, selectedIDs []int, includeBNodes bool) ([]N
 	return out, set
 }
 
-func idsFromBindings(raw []byte, varName string, idx Index, selectedSet map[int]struct{}, includeBNodes bool) ([]int, error) {
+func idsFromBindings(raw []byte, varName string, idx Index, selectedSet map[uint32]struct{}, includeBNodes bool) ([]uint32, error) {
 	var res sparqlResponse
 	if err := json.Unmarshal(raw, &res); err != nil {
 		return nil, fmt.Errorf("failed to parse SPARQL JSON: %w", err)
 	}
 
-	neighborSet := make(map[int]struct{})
+	neighborSet := make(map[uint32]struct{})
 	for _, b := range res.Results.Bindings {
 		term, ok := b[varName]
 		if !ok {
@@ -92,11 +92,10 @@ func idsFromBindings(raw []byte, varName string, idx Index, selectedSet map[int]
 		neighborSet[nid] = struct{}{}
 	}
 
-	ids := make([]int, 0, len(neighborSet))
+	ids := make([]uint32, 0, len(neighborSet))
 	for nid := range neighborSet {
 		ids = append(ids, nid)
 	}
-	sort.Ints(ids)
+	sort.Slice(ids, func(i, j int) bool { return ids[i] < ids[j] })
 	return ids, nil
 }
-
diff --git a/backend_go/selection_queries/neighbors.go b/backend_go/selection_queries/neighbors.go
index 102f47c..60ccd91 100644
--- a/backend_go/selection_queries/neighbors.go
+++ b/backend_go/selection_queries/neighbors.go
@@ -62,10 +62,10 @@ WHERE {
 `, values, bnodeFilter)
 }
 
-func runNeighbors(ctx context.Context, q Querier, idx Index, selectedIDs []int, includeBNodes bool) ([]int, error) {
+func runNeighbors(ctx context.Context, q Querier, idx Index, selectedIDs []uint32, includeBNodes bool) ([]uint32, error) {
 	selectedNodes, selectedSet := selectedNodesFromIDs(idx, selectedIDs, includeBNodes)
 	if len(selectedNodes) == 0 {
-		return []int{}, nil
+		return []uint32{}, nil
 	}
 
 	raw, err := q.Query(ctx, neighborsQuery(selectedNodes, includeBNodes))
@@ -74,4 +74,3 @@ func runNeighbors(ctx context.Context, q Querier, idx Index, selectedIDs []int,
 	}
 	return idsFromBindings(raw, "nbr", idx, selectedSet, includeBNodes)
 }
-
diff --git a/backend_go/selection_queries/subclasses.go b/backend_go/selection_queries/subclasses.go
index c14c4e1..9de4151 100644
--- a/backend_go/selection_queries/subclasses.go
+++ b/backend_go/selection_queries/subclasses.go
@@ -40,10 +40,10 @@ WHERE {
 `, values, bnodeFilter)
 }
 
-func runSubclasses(ctx context.Context, q Querier, idx Index, selectedIDs []int, includeBNodes bool) ([]int, error) {
+func runSubclasses(ctx context.Context, q Querier, idx Index, selectedIDs []uint32, includeBNodes bool) ([]uint32, error) {
 	selectedNodes, selectedSet := selectedNodesFromIDs(idx, selectedIDs, includeBNodes)
 	if len(selectedNodes) == 0 {
-		return []int{}, nil
+		return []uint32{}, nil
 	}
 
 	raw, err := q.Query(ctx, subclassesQuery(selectedNodes, includeBNodes))
@@ -52,4 +52,3 @@ func runSubclasses(ctx context.Context, q Querier, idx Index, selectedIDs []int,
 	}
 	return idsFromBindings(raw, "nbr", idx, selectedSet, includeBNodes)
 }
-
diff --git a/backend_go/selection_queries/superclasses.go b/backend_go/selection_queries/superclasses.go
index 8d2542e..8841941 100644
--- a/backend_go/selection_queries/superclasses.go
+++ b/backend_go/selection_queries/superclasses.go
@@ -40,10 +40,10 @@ WHERE {
 `, values, bnodeFilter)
 }
 
-func runSuperclasses(ctx context.Context, q Querier, idx Index, selectedIDs []int, includeBNodes bool) ([]int, error) {
+func runSuperclasses(ctx context.Context, q Querier, idx Index, selectedIDs []uint32, includeBNodes bool) ([]uint32, error) {
 	selectedNodes, selectedSet := selectedNodesFromIDs(idx, selectedIDs, includeBNodes)
 	if len(selectedNodes) == 0 {
-		return []int{}, nil
+		return []uint32{}, nil
 	}
 
 	raw, err := q.Query(ctx, superclassesQuery(selectedNodes, includeBNodes))
@@ -52,4 +52,3 @@ func runSuperclasses(ctx context.Context, q Querier, idx Index, selectedIDs []in
 	}
 	return idsFromBindings(raw, "nbr", idx, selectedSet, includeBNodes)
 }
-
diff --git a/backend_go/selection_queries/types.go b/backend_go/selection_queries/types.go
index ed800c7..62467bb 100644
--- a/backend_go/selection_queries/types.go
+++ b/backend_go/selection_queries/types.go
@@ -7,14 +7,14 @@ type Querier interface {
 }
 
 type NodeRef struct {
-	ID       int
+	ID       uint32
 	TermType string // "uri" | "bnode"
 	IRI      string
 }
 
 type Index struct {
-	IDToNode map[int]NodeRef
-	KeyToID  map[string]int
+	IDToNode map[uint32]NodeRef
+	KeyToID  map[string]uint32
 }
 
 type Meta struct {
@@ -24,6 +24,5 @@ type Meta struct {
 
 type Definition struct {
 	Meta Meta
-	Run  func(ctx context.Context, q Querier, idx Index, selectedIDs []int, includeBNodes bool) ([]int, error)
+	Run  func(ctx context.Context, q Querier, idx Index, selectedIDs []uint32, includeBNodes bool) ([]uint32, error)
 }
-
diff --git a/backend_go/selection_query.go b/backend_go/selection_query.go
index f8935cd..825296d 100644
--- a/backend_go/selection_query.go
+++ b/backend_go/selection_query.go
@@ -12,16 +12,16 @@ func runSelectionQuery(
 	sparql *AnzoGraphClient,
 	snapshot GraphResponse,
 	queryID string,
-	selectedIDs []int,
+	selectedIDs []uint32,
 	includeBNodes bool,
-) ([]int, error) {
+) ([]uint32, error) {
 	def, ok := selectionqueries.Get(queryID)
 	if !ok {
 		return nil, fmt.Errorf("unknown query_id: %s", queryID)
 	}
 
-	idToNode := make(map[int]selectionqueries.NodeRef, len(snapshot.Nodes))
-	keyToID := make(map[string]int, len(snapshot.Nodes))
+	idToNode := make(map[uint32]selectionqueries.NodeRef, len(snapshot.Nodes))
+	keyToID := make(map[string]uint32, len(snapshot.Nodes))
 	for _, n := range snapshot.Nodes {
 		nr := selectionqueries.NodeRef{ID: n.ID, TermType: n.TermType, IRI: n.IRI}
 		idToNode[n.ID] = nr
@@ -30,4 +30,3 @@ func runSelectionQuery(
 
 	return def.Run(ctx, sparql, selectionqueries.Index{IDToNode: idToNode, KeyToID: keyToID}, selectedIDs, includeBNodes)
 }
-
diff --git a/backend_go/server.go b/backend_go/server.go
index 18ea5d9..9a1da31 100644
--- a/backend_go/server.go
+++ b/backend_go/server.go
@@ -189,7 +189,7 @@ func (s *APIServer) handleSelectionQuery(w http.ResponseWriter, r *http.Request)
 		writeJSON(w, http.StatusOK, SelectionQueryResponse{
 			QueryID:     req.QueryID,
 			SelectedIDs: req.SelectedIDs,
-			NeighborIDs: []int{},
+			NeighborIDs: []uint32{},
 		})
 		return
 	}
@@ -247,7 +247,7 @@ func (s *APIServer) handleNeighbors(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 	if len(req.SelectedIDs) == 0 {
-		writeJSON(w, http.StatusOK, NeighborsResponse{SelectedIDs: req.SelectedIDs, NeighborIDs: []int{}})
+		writeJSON(w, http.StatusOK, NeighborsResponse{SelectedIDs: req.SelectedIDs, NeighborIDs: []uint32{}})
 		return
 	}