diff --git a/go.mod b/go.mod
index 1568ea8..3d22c30 100644
--- a/go.mod
+++ b/go.mod
@@ -36,6 +36,7 @@ require (
 	github.com/muesli/termenv v0.16.0 // indirect
 	github.com/rivo/uniseg v0.4.7 // indirect
 	github.com/xo/terminfo v0.0.0-20220910002029-abceb7e1c41e // indirect
+	go.etcd.io/bbolt v1.4.3 // indirect
 	golang.org/x/exp v0.0.0-20240719175910-8a7402abbf56 // indirect
 	golang.org/x/sys v0.36.0 // indirect
 	golang.org/x/text v0.23.0 // indirect
diff --git a/go.sum b/go.sum
index 964e6ee..1e17dd9 100644
--- a/go.sum
+++ b/go.sum
@@ -63,6 +63,8 @@ github.com/stretchr/testify v1.10.0 h1:Xv5erBjTwe/5IxqUQTdXv5kgmIvbHo3QQyRwhJsOf
 github.com/stretchr/testify v1.10.0/go.mod h1:r2ic/lqez/lEtzL7wO/rwa5dbSLXVDPFyf8C91i36aY=
 github.com/xo/terminfo v0.0.0-20220910002029-abceb7e1c41e h1:JVG44RsyaB9T2KIHavMF/ppJZNG9ZpyihvCd0w101no=
 github.com/xo/terminfo v0.0.0-20220910002029-abceb7e1c41e/go.mod h1:RbqR21r5mrJuqunuUZ/Dhy/avygyECGrLceyNeo4LiM=
+go.etcd.io/bbolt v1.4.3 h1:dEadXpI6G79deX5prL3QRNP6JB8UxVkqo4UPnHaNXJo=
+go.etcd.io/bbolt v1.4.3/go.mod h1:tKQlpPaYCVFctUIgFKFnAlvbmB3tpy1vkTnDWohtc0E=
 golang.org/x/crypto v0.36.0 h1:AnAEvhDddvBdpY+uR+MyHmuZzzNqXSe/GvuDeob5L34=
 golang.org/x/crypto v0.36.0/go.mod h1:Y4J0ReaxCR1IMaabaSMugxJES1EpwhBHhv2bDHklZvc=
 golang.org/x/exp v0.0.0-20240719175910-8a7402abbf56 h1:2dVuKD2vS7b0QIHQbpyTISPd0LeHDbnYEryqj5Q1ug8=
diff --git a/store/db.go b/store/db.go
new file mode 100644
index 0000000..14036a7
--- /dev/null
+++ b/store/db.go
@@ -0,0 +1,105 @@
+package store
+
+import (
+	"encoding/json"
+	"fmt"
+	"sort"
+
+	bolt "go.etcd.io/bbolt"
+)
+
+var (
+	bucketProfiles = []byte("profiles")
+	bucketRankings = []byte("rankings")
+)
+
+type DB struct {
+	db *bolt.DB
+}
+
+type RunRecord struct {
+	Player string `json:"player"`
+	Floor  int    `json:"floor"`
+	Score  int    `json:"score"`
+}
+
+func Open(path string) (*DB, error) {
+	db, err := bolt.Open(path, 0600, nil)
+	if err != nil {
+		return nil, err
+	}
+	err = db.Update(func(tx *bolt.Tx) error {
+		if _, err := tx.CreateBucketIfNotExists(bucketProfiles); err != nil {
+			return err
+		}
+		if _, err := tx.CreateBucketIfNotExists(bucketRankings); err != nil {
+			return err
+		}
+		return nil
+	})
+	return &DB{db: db}, err
+}
+
+func (d *DB) Close() error {
+	return d.db.Close()
+}
+
+func (d *DB) SaveProfile(fingerprint, name string) error {
+	return d.db.Update(func(tx *bolt.Tx) error {
+		return tx.Bucket(bucketProfiles).Put([]byte(fingerprint), []byte(name))
+	})
+}
+
+func (d *DB) GetProfile(fingerprint string) (string, error) {
+	var name string
+	err := d.db.View(func(tx *bolt.Tx) error {
+		v := tx.Bucket(bucketProfiles).Get([]byte(fingerprint))
+		if v == nil {
+			return fmt.Errorf("profile not found")
+		}
+		name = string(v)
+		return nil
+	})
+	return name, err
+}
+
+func (d *DB) SaveRun(player string, floor, score int) error {
+	return d.db.Update(func(tx *bolt.Tx) error {
+		b := tx.Bucket(bucketRankings)
+		id, _ := b.NextSequence()
+		record := RunRecord{Player: player, Floor: floor, Score: score}
+		data, err := json.Marshal(record)
+		if err != nil {
+			return err
+		}
+		return b.Put([]byte(fmt.Sprintf("%010d", id)), data)
+	})
+}
+
+func (d *DB) TopRuns(limit int) ([]RunRecord, error) {
+	var runs []RunRecord
+	err := d.db.View(func(tx *bolt.Tx) error {
+		b := tx.Bucket(bucketRankings)
+		return b.ForEach(func(k, v []byte) error {
+			var r RunRecord
+			if err := json.Unmarshal(v, &r); err != nil {
+				return err
+			}
+			runs = append(runs, r)
+			return nil
+		})
+	})
+	if err != nil {
+		return nil, err
+	}
+	sort.Slice(runs, func(i, j int) bool {
+		if runs[i].Floor != runs[j].Floor {
+			return runs[i].Floor > runs[j].Floor
+		}
+		return runs[i].Score > runs[j].Score
+	})
+	if len(runs) > limit {
+		runs = runs[:limit]
+	}
+	return runs, nil
+}
diff --git a/store/db_test.go b/store/db_test.go
new file mode 100644
index 0000000..0b49937
--- /dev/null
+++ b/store/db_test.go
@@ -0,0 +1,55 @@
+package store
+
+import (
+	"os"
+	"testing"
+)
+
+func TestPlayerProfile(t *testing.T) {
+	db, err := Open("test.db")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer func() {
+		db.Close()
+		os.Remove("test.db")
+	}()
+
+	err = db.SaveProfile("SHA256:abc123", "TestPlayer")
+	if err != nil {
+		t.Fatal(err)
+	}
+	name, err := db.GetProfile("SHA256:abc123")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if name != "TestPlayer" {
+		t.Errorf("Name: got %q, want %q", name, "TestPlayer")
+	}
+}
+
+func TestRanking(t *testing.T) {
+	db, err := Open("test_rank.db")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer func() {
+		db.Close()
+		os.Remove("test_rank.db")
+	}()
+
+	db.SaveRun("Alice", 20, 1500)
+	db.SaveRun("Bob", 15, 1000)
+	db.SaveRun("Charlie", 20, 2000)
+
+	rankings, err := db.TopRuns(10)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(rankings) != 3 {
+		t.Errorf("Rankings: got %d, want 3", len(rankings))
+	}
+	if rankings[0].Player != "Charlie" {
+		t.Errorf("Top player: got %q, want Charlie", rankings[0].Player)
+	}
+}