diff --git a/statediff/builder.go b/statediff/builder.go
index 6299edb23..291cdbb8a 100644
--- a/statediff/builder.go
+++ b/statediff/builder.go
@@ -200,7 +200,7 @@ func (sdb *StateDiffBuilder) createdAndUpdatedState(a, b trie.NodeIterator,
 	it, itCount := trie.NewDifferenceIterator(a, b)
 	for it.Next(true) {
 		// ignore node if it is not along paths of interest
-		if watchingAddresses && !isValidPrefixPath(watchedAddressesLeafPaths, append(prefixPath, it.Path()...)) {
+		if watchingAddresses && !isValidPrefixPath(watchedAddressesLeafPaths, it.Path()) {
 			continue
 		}
 		// index values by leaf key
@@ -234,7 +234,8 @@ func (sdb *StateDiffBuilder) createdAndUpdatedState(a, b trie.NodeIterator,
 					return nil, err
 				}
 				if ok {
-					nodePath := append(prefixPath, it.Path()...)
+					nodePath := make([]byte, len(it.Path()))
+					copy(nodePath, it.Path())
 					partialPath := trie.CompactToHex(elements[0].([]byte))
 					valueNodePath := append(nodePath, partialPath...)
 					if !isWatchedAddress(watchedAddressesLeafPaths, valueNodePath) {
@@ -261,7 +262,7 @@ func (sdb *StateDiffBuilder) createdAndUpdatedState(a, b trie.NodeIterator,
 func (sdb *StateDiffBuilder) processStateValueNode(it trie.NodeIterator, watchedAddressesLeafPaths [][]byte, prefixPath []byte) (*types2.AccountWrapper, error) {
 	// skip if it is not a watched address
 	// If we aren't watching any specific addresses, we are watching everything
-	if len(watchedAddressesLeafPaths) > 0 && !isWatchedAddress(watchedAddressesLeafPaths, append(prefixPath, it.Path()...)) {
+	if len(watchedAddressesLeafPaths) > 0 && !isWatchedAddress(watchedAddressesLeafPaths, it.Path()) {
 		return nil, nil
 	}
 
@@ -309,7 +310,7 @@ func (sdb *StateDiffBuilder) deletedOrUpdatedState(a, b trie.NodeIterator, diffA
 	it, _ := trie.NewDifferenceIterator(b, a)
 	for it.Next(true) {
 		// ignore node if it is not along paths of interest
-		if watchingAddresses && !isValidPrefixPath(watchedAddressesLeafPaths, append(prefixPath, it.Path()...)) {
+		if watchingAddresses && !isValidPrefixPath(watchedAddressesLeafPaths, it.Path()) {
 			continue
 		}
 
diff --git a/statediff/indexer/database/metrics/metrics.go b/statediff/indexer/database/metrics/metrics.go
index 34cb3a69b..6174e203c 100644
--- a/statediff/indexer/database/metrics/metrics.go
+++ b/statediff/indexer/database/metrics/metrics.go
@@ -253,7 +253,7 @@ func (met *dbMetricsHandles) Update(stats DbStats) {
 
 func ReportAndUpdateDuration(msg string, start time.Time, logger log.Logger, timer metrics.Timer) {
 	since := UpdateDuration(start, timer)
-	logger.Debug(fmt.Sprintf("%s duration=%dms", msg, since.Milliseconds()))
+	logger.Trace(fmt.Sprintf("%s duration=%dms", msg, since.Milliseconds()))
 }
 
 func UpdateDuration(start time.Time, timer metrics.Timer) time.Duration {
diff --git a/statediff/indexer/database/sql/pgx_indexer_legacy_test.go b/statediff/indexer/database/sql/pgx_indexer_legacy_test.go
index 80094a8d0..b07987754 100644
--- a/statediff/indexer/database/sql/pgx_indexer_legacy_test.go
+++ b/statediff/indexer/database/sql/pgx_indexer_legacy_test.go
@@ -28,7 +28,7 @@ import (
 )
 
 func setupLegacyPGXIndexer(t *testing.T) {
-	db, err = postgres.SetupPGXDB(postgres.DefaultConfig)
+	db, err = postgres.SetupPGXDB(postgres.TestConfig)
 	if err != nil {
 		t.Fatal(err)
 	}
diff --git a/statediff/indexer/database/sql/pgx_indexer_test.go b/statediff/indexer/database/sql/pgx_indexer_test.go
index c0ce57c1f..27e9f2080 100644
--- a/statediff/indexer/database/sql/pgx_indexer_test.go
+++ b/statediff/indexer/database/sql/pgx_indexer_test.go
@@ -39,7 +39,7 @@ func setupPGXIndexer(t *testing.T, config postgres.Config) {
 }
 
 func setupPGX(t *testing.T) {
-	setupPGXWithConfig(t, postgres.DefaultConfig)
+	setupPGXWithConfig(t, postgres.TestConfig)
 }
 
 func setupPGXWithConfig(t *testing.T, config postgres.Config) {
@@ -48,7 +48,7 @@ func setupPGXWithConfig(t *testing.T, config postgres.Config) {
 }
 
 func setupPGXNonCanonical(t *testing.T) {
-	setupPGXIndexer(t, postgres.DefaultConfig)
+	setupPGXIndexer(t, postgres.TestConfig)
 	test.SetupTestDataNonCanonical(t, ind)
 }
 
@@ -103,7 +103,7 @@ func TestPGXIndexer(t *testing.T) {
 	})
 
 	t.Run("Publish and index with CopyFrom enabled.", func(t *testing.T) {
-		config := postgres.DefaultConfig
+		config := postgres.TestConfig
 		config.CopyFrom = true
 
 		setupPGXWithConfig(t, config)
@@ -169,7 +169,7 @@ func TestPGXIndexerNonCanonical(t *testing.T) {
 }
 
 func TestPGXWatchAddressMethods(t *testing.T) {
-	setupPGXIndexer(t, postgres.DefaultConfig)
+	setupPGXIndexer(t, postgres.TestConfig)
 	defer tearDown(t)
 	defer checkTxClosure(t, 1, 0, 1)
 
diff --git a/statediff/indexer/database/sql/postgres/config.go b/statediff/indexer/database/sql/postgres/config.go
index 1cbec55c1..28c5aaa92 100644
--- a/statediff/indexer/database/sql/postgres/config.go
+++ b/statediff/indexer/database/sql/postgres/config.go
@@ -56,13 +56,14 @@ func ResolveDriverType(str string) (DriverType, error) {
 	}
 }
 
-// DefaultConfig are default parameters for connecting to a Postgres sql
-var DefaultConfig = Config{
+// TestConfig specifies default parameters for connecting to a testing DB
+var TestConfig = Config{
 	Hostname:     "localhost",
 	Port:         8077,
 	DatabaseName: "cerc_testing",
 	Username:     "vdbm",
 	Password:     "password",
+	Driver:       SQLX,
 }
 
 // Config holds params for a Postgres db
diff --git a/statediff/indexer/database/sql/postgres/pgx_test.go b/statediff/indexer/database/sql/postgres/pgx_test.go
index 043112e8d..86d082ace 100644
--- a/statediff/indexer/database/sql/postgres/pgx_test.go
+++ b/statediff/indexer/database/sql/postgres/pgx_test.go
@@ -31,7 +31,7 @@ import (
 )
 
 var (
-	pgConfig, _ = postgres.MakeConfig(postgres.DefaultConfig)
+	pgConfig, _ = postgres.MakeConfig(postgres.TestConfig)
 	ctx         = context.Background()
 )
 
@@ -111,7 +111,7 @@ func TestPostgresPGX(t *testing.T) {
 		badHash := fmt.Sprintf("x %s", strings.Repeat("1", 100))
 		badInfo := node.Info{GenesisBlock: badHash, NetworkID: "1", ID: "x123", ClientName: "geth"}
 
-		_, err := postgres.NewPGXDriver(ctx, postgres.DefaultConfig, badInfo)
+		_, err := postgres.NewPGXDriver(ctx, postgres.TestConfig, badInfo)
 		if err == nil {
 			t.Fatal("Expected an error")
 		}
diff --git a/statediff/indexer/database/sql/postgres/sqlx_test.go b/statediff/indexer/database/sql/postgres/sqlx_test.go
index 40b976314..903f8715b 100644
--- a/statediff/indexer/database/sql/postgres/sqlx_test.go
+++ b/statediff/indexer/database/sql/postgres/sqlx_test.go
@@ -35,7 +35,7 @@ func TestPostgresSQLX(t *testing.T) {
 
 	t.Run("connects to the database", func(t *testing.T) {
 		var err error
-		connStr := postgres.DefaultConfig.DbConnectionString()
+		connStr := postgres.TestConfig.DbConnectionString()
 
 		sqlxdb, err = sqlx.Connect("postgres", connStr)
 		if err != nil {
@@ -58,7 +58,7 @@ func TestPostgresSQLX(t *testing.T) {
 		// sized int, so use string representation of big.Int
 		// and cast on insert
 
-		connStr := postgres.DefaultConfig.DbConnectionString()
+		connStr := postgres.TestConfig.DbConnectionString()
 		db, err := sqlx.Connect("postgres", connStr)
 		if err != nil {
 			t.Fatal(err)
@@ -109,7 +109,7 @@ func TestPostgresSQLX(t *testing.T) {
 		badHash := fmt.Sprintf("x %s", strings.Repeat("1", 100))
 		badInfo := node.Info{GenesisBlock: badHash, NetworkID: "1", ID: "x123", ClientName: "geth"}
 
-		_, err := postgres.NewSQLXDriver(ctx, postgres.DefaultConfig, badInfo)
+		_, err := postgres.NewSQLXDriver(ctx, postgres.TestConfig, badInfo)
 		if err == nil {
 			t.Fatal("Expected an error")
 		}
diff --git a/statediff/indexer/database/sql/postgres/test_helpers.go b/statediff/indexer/database/sql/postgres/test_helpers.go
index cb5255429..75c50e315 100644
--- a/statediff/indexer/database/sql/postgres/test_helpers.go
+++ b/statediff/indexer/database/sql/postgres/test_helpers.go
@@ -25,7 +25,7 @@ import (
 
 // SetupSQLXDB is used to setup a sqlx db for tests
 func SetupSQLXDB() (sql.Database, error) {
-	conf := DefaultConfig
+	conf := TestConfig
 	conf.MaxIdle = 0
 	driver, err := NewSQLXDriver(context.Background(), conf, node.Info{})
 	if err != nil {
diff --git a/statediff/service_test.go b/statediff/service_test.go
index ceea79ece..6e6ad200c 100644
--- a/statediff/service_test.go
+++ b/statediff/service_test.go
@@ -54,8 +54,8 @@ var (
 	parentHeader1 = types.Header{Number: big.NewInt(rand.Int63()), Root: parentRoot1}
 	parentHeader2 = types.Header{Number: big.NewInt(rand.Int63()), Root: parentRoot2}
 
-	parentBlock1 = types.NewBlock(&parentHeader1, nil, nil, nil, new(trie.Trie))
-	parentBlock2 = types.NewBlock(&parentHeader2, nil, nil, nil, new(trie.Trie))
+	parentBlock1 = types.NewBlock(&parentHeader1, nil, nil, nil, trie.NewEmpty(nil))
+	parentBlock2 = types.NewBlock(&parentHeader2, nil, nil, nil, trie.NewEmpty(nil))
 
 	parentHash1 = parentBlock1.Hash()
 	parentHash2 = parentBlock2.Hash()
@@ -67,9 +67,9 @@ var (
 	header2   = types.Header{ParentHash: parentHash2, Root: testRoot2, Number: big.NewInt(2)}
 	header3   = types.Header{ParentHash: common.HexToHash("parent hash"), Root: testRoot3, Number: big.NewInt(3)}
 
-	testBlock1 = types.NewBlock(&header1, nil, nil, nil, new(trie.Trie))
-	testBlock2 = types.NewBlock(&header2, nil, nil, nil, new(trie.Trie))
-	testBlock3 = types.NewBlock(&header3, nil, nil, nil, new(trie.Trie))
+	testBlock1 = types.NewBlock(&header1, nil, nil, nil, trie.NewEmpty(nil))
+	testBlock2 = types.NewBlock(&header2, nil, nil, nil, trie.NewEmpty(nil))
+	testBlock3 = types.NewBlock(&header3, nil, nil, nil, trie.NewEmpty(nil))
 
 	receiptRoot1  = common.HexToHash("0x05")
 	receiptRoot2  = common.HexToHash("0x06")
diff --git a/trie/concurrent_iterator/iterator.go b/trie/concurrent_iterator/iterator.go
index de015ad87..5bd5f7f59 100644
--- a/trie/concurrent_iterator/iterator.go
+++ b/trie/concurrent_iterator/iterator.go
@@ -31,6 +31,10 @@ type PrefixBoundIterator struct {
 	EndPath   []byte
 }
 
+// IteratorConstructor is a constructor returning a NodeIterator, which is used to decouple this
+// code from the trie implementation.
+type IteratorConstructor = func(startKey []byte) trie.NodeIterator
+
 func (it *PrefixBoundIterator) Next(descend bool) bool {
 	if it.EndPath == nil {
 		return it.NodeIterator.Next(descend)
@@ -130,10 +134,10 @@ func eachPrefixRange(prefix []byte, nbins uint, callback func([]byte, []byte)) {
 }
 
 // SubtrieIterators cuts a trie by path prefix, returning `nbins` iterators covering its subtries
-func SubtrieIterators(tree state.Trie, nbins uint) []trie.NodeIterator {
+func SubtrieIterators(makeIterator IteratorConstructor, nbins uint) []trie.NodeIterator {
 	var iters []trie.NodeIterator
 	eachPrefixRange(nil, nbins, func(from []byte, to []byte) {
-		it := tree.NodeIterator(HexToKeyBytes(from))
+		it := makeIterator(HexToKeyBytes(from))
 		iters = append(iters, NewPrefixBoundIterator(it, from, to))
 	})
 	return iters
diff --git a/trie/concurrent_iterator/iterator_test.go b/trie/concurrent_iterator/iterator_test.go
index de3080ff8..b39e60e25 100644
--- a/trie/concurrent_iterator/iterator_test.go
+++ b/trie/concurrent_iterator/iterator_test.go
@@ -82,7 +82,7 @@ func TestIterator(t *testing.T) {
 		allPaths := fixt.Block1_Paths
 		cases := []uint{1, 2, 4, 8, 16, 32}
 		runCase := func(t *testing.T, nbins uint) {
-			iters := iter.SubtrieIterators(tree, nbins)
+			iters := iter.SubtrieIterators(tree.NodeIterator, nbins)
 			ix := 0
 			for b := uint(0); b < nbins; b++ {
 				for it := iters[b]; it.Next(true); ix++ {
diff --git a/trie/concurrent_iterator/tracker/tracker.go b/trie/concurrent_iterator/tracker/tracker.go
index 0ee5dad80..7c7029048 100644
--- a/trie/concurrent_iterator/tracker/tracker.go
+++ b/trie/concurrent_iterator/tracker/tracker.go
@@ -9,7 +9,6 @@ import (
 	"os/signal"
 	"syscall"
 
-	"github.com/ethereum/go-ethereum/core/state"
 	"github.com/ethereum/go-ethereum/log"
 	"github.com/ethereum/go-ethereum/trie"
 
@@ -122,7 +121,7 @@ func (tr *Tracker) dump() error {
 
 // Restore attempts to read iterator state from file
 // if file doesn't exist, returns an empty slice with no error
-func (tr *Tracker) Restore(tree state.Trie) ([]trie.NodeIterator, error) {
+func (tr *Tracker) Restore(makeIterator iter.IteratorConstructor) ([]trie.NodeIterator, error) {
 	file, err := os.Open(tr.recoveryFile)
 	if err != nil {
 		if os.IsNotExist(err) {
@@ -169,7 +168,7 @@ func (tr *Tracker) Restore(tree state.Trie) ([]trie.NodeIterator, error) {
 			decrementPath(startPath)
 			startPath = append(startPath, 0)
 		}
-		it := iter.NewPrefixBoundIterator(tree.NodeIterator(iter.HexToKeyBytes(startPath)), startPath, endPath)
+		it := iter.NewPrefixBoundIterator(makeIterator(iter.HexToKeyBytes(startPath)), startPath, endPath)
 		ret = append(ret, tr.Tracked(it, recoveredPath))
 	}