diff --git a/backend/go.mod b/backend/go.mod
index 0adeaa41..339dbde3 100644
--- a/backend/go.mod
+++ b/backend/go.mod
@@ -19,6 +19,7 @@ require (
 	github.com/golang-migrate/migrate/v4 v4.18.2
 	github.com/google/uuid v1.6.0
 	github.com/hashicorp/go-uuid v1.0.3
+	github.com/jinzhu/copier v0.4.0
 	github.com/joho/godotenv v1.5.1
 	github.com/lestrrat-go/httprc/v3 v3.0.0-beta2
 	github.com/lestrrat-go/jwx/v3 v3.0.1
diff --git a/backend/go.sum b/backend/go.sum
index 7e3a5370..9fccec08 100644
--- a/backend/go.sum
+++ b/backend/go.sum
@@ -140,6 +140,8 @@ github.com/jcmturner/gokrb5/v8 v8.4.4 h1:x1Sv4HaTpepFkXbt2IkL29DXRf8sOfZXo8eRKh6
 github.com/jcmturner/gokrb5/v8 v8.4.4/go.mod h1:1btQEpgT6k+unzCwX1KdWMEwPPkkgBtP+F6aCACiMrs=
 github.com/jcmturner/rpc/v2 v2.0.3 h1:7FXXj8Ti1IaVFpSAziCZWNzbNuZmnvw/i6CqLNdWfZY=
 github.com/jcmturner/rpc/v2 v2.0.3/go.mod h1:VUJYCIDm3PVOEHw8sgt091/20OJjskO/YJki3ELg/Hc=
+github.com/jinzhu/copier v0.4.0 h1:w3ciUoD19shMCRargcpm0cm91ytaBhDvuRpz1ODO/U8=
+github.com/jinzhu/copier v0.4.0/go.mod h1:DfbEm0FYsaqBcKcFuvmOZb218JkPGtvSHsKg8S8hyyg=
 github.com/jinzhu/inflection v1.0.0 h1:K317FqzuhWc8YvSVlFMCCUb36O/S9MCKRDI7QkRKD/E=
 github.com/jinzhu/inflection v1.0.0/go.mod h1:h+uFLlag+Qp1Va5pdKtLDYj+kHp5pxUVkryuEj+Srlc=
 github.com/jinzhu/now v1.1.5 h1:/o9tlHleP7gOFmsnYNz3RGnqzefHA47wQpKrrdTIwXQ=
diff --git a/backend/internal/dto/dto_mapper.go b/backend/internal/dto/dto_mapper.go
index f727dfc9..ff69d43e 100644
--- a/backend/internal/dto/dto_mapper.go
+++ b/backend/internal/dto/dto_mapper.go
@@ -1,162 +1,27 @@
 package dto
 
 import (
-	"errors"
-	"reflect"
-	"time"
+	"fmt"
 
-	datatype "github.com/pocket-id/pocket-id/backend/internal/model/types"
+	"github.com/jinzhu/copier"
 )
 
 // MapStructList maps a list of source structs to a list of destination structs
-func MapStructList[S any, D any](source []S, destination *[]D) error {
-	*destination = make([]D, 0, len(source))
+func MapStructList[S any, D any](source []S, destination *[]D) (err error) {
+	*destination = make([]D, len(source))
 
-	for _, item := range source {
-		var destItem D
-		if err := MapStruct(item, &destItem); err != nil {
-			return err
+	for i, item := range source {
+		err = MapStruct(item, &((*destination)[i]))
+		if err != nil {
+			return fmt.Errorf("failed to map field %d: %w", i, err)
 		}
-		*destination = append(*destination, destItem)
 	}
 	return nil
 }
 
 // MapStruct maps a source struct to a destination struct
-func MapStruct[S any, D any](source S, destination *D) error {
-	// Ensure destination is a non-nil pointer
-	destValue := reflect.ValueOf(destination)
-	if destValue.Kind() != reflect.Ptr || destValue.IsNil() {
-		return errors.New("destination must be a non-nil pointer to a struct")
-	}
-
-	// Ensure source is a struct
-	sourceValue := reflect.ValueOf(source)
-	if sourceValue.Kind() != reflect.Struct {
-		return errors.New("source must be a struct")
-	}
-
-	return mapStructInternal(sourceValue, destValue.Elem())
-}
-
-func mapStructInternal(sourceVal reflect.Value, destVal reflect.Value) error {
-	for i := 0; i < destVal.NumField(); i++ {
-		destField := destVal.Field(i)
-		destFieldType := destVal.Type().Field(i)
-
-		if destFieldType.Anonymous {
-			if err := mapStructInternal(sourceVal, destField); err != nil {
-				return err
-			}
-			continue
-		}
-
-		sourceField := sourceVal.FieldByName(destFieldType.Name)
-
-		if sourceField.IsValid() && destField.CanSet() {
-			if err := mapField(sourceField, destField); err != nil {
-				return err
-			}
-		}
-	}
-	return nil
-}
-
-//nolint:gocognit
-func mapField(sourceField reflect.Value, destField reflect.Value) error {
-	// Handle pointer to struct in source
-	if sourceField.Kind() == reflect.Ptr && !sourceField.IsNil() {
-		switch {
-		case sourceField.Elem().Kind() == reflect.Struct:
-			switch {
-			case destField.Kind() == reflect.Struct:
-				// Map from pointer to struct -> struct
-				return mapStructInternal(sourceField.Elem(), destField)
-			case destField.Kind() == reflect.Ptr && destField.CanSet():
-				// Map from pointer to struct -> pointer to struct
-				if destField.IsNil() {
-					destField.Set(reflect.New(destField.Type().Elem()))
-				}
-				return mapStructInternal(sourceField.Elem(), destField.Elem())
-			}
-		case destField.Kind() == reflect.Ptr &&
-			destField.CanSet() &&
-			sourceField.Elem().Type().AssignableTo(destField.Type().Elem()):
-			// Handle primitive pointer types (e.g., *string to *string)
-			if destField.IsNil() {
-				destField.Set(reflect.New(destField.Type().Elem()))
-			}
-			destField.Elem().Set(sourceField.Elem())
-			return nil
-		case destField.Kind() != reflect.Ptr &&
-			destField.CanSet() &&
-			sourceField.Elem().Type().AssignableTo(destField.Type()):
-			// Handle *T to T conversion for primitive types
-			destField.Set(sourceField.Elem())
-			return nil
-		}
-	}
-
-	// Handle pointer to struct in destination
-	if destField.Kind() == reflect.Ptr && destField.CanSet() {
-		switch {
-		case sourceField.Kind() == reflect.Struct:
-			// Map from struct -> pointer to struct
-			if destField.IsNil() {
-				destField.Set(reflect.New(destField.Type().Elem()))
-			}
-			return mapStructInternal(sourceField, destField.Elem())
-		case !sourceField.IsZero() && sourceField.Type().AssignableTo(destField.Type().Elem()):
-			// Handle T to *T conversion for primitive types
-			if destField.IsNil() {
-				destField.Set(reflect.New(destField.Type().Elem()))
-			}
-			destField.Elem().Set(sourceField)
-			return nil
-		}
-	}
-
-	switch {
-	case sourceField.Type() == destField.Type():
-		destField.Set(sourceField)
-	case sourceField.Kind() == reflect.Slice && destField.Kind() == reflect.Slice:
-		return mapSlice(sourceField, destField)
-	case sourceField.Kind() == reflect.Struct && destField.Kind() == reflect.Struct:
-		return mapStructInternal(sourceField, destField)
-	default:
-		return mapSpecialTypes(sourceField, destField)
-	}
-	return nil
-}
-
-func mapSlice(sourceField reflect.Value, destField reflect.Value) error {
-	if sourceField.Type().Elem() == destField.Type().Elem() {
-		newSlice := reflect.MakeSlice(destField.Type(), sourceField.Len(), sourceField.Cap())
-		for j := 0; j < sourceField.Len(); j++ {
-			newSlice.Index(j).Set(sourceField.Index(j))
-		}
-		destField.Set(newSlice)
-	} else if sourceField.Type().Elem().Kind() == reflect.Struct && destField.Type().Elem().Kind() == reflect.Struct {
-		newSlice := reflect.MakeSlice(destField.Type(), sourceField.Len(), sourceField.Cap())
-		for j := 0; j < sourceField.Len(); j++ {
-			sourceElem := sourceField.Index(j)
-			destElem := reflect.New(destField.Type().Elem()).Elem()
-			if err := mapStructInternal(sourceElem, destElem); err != nil {
-				return err
-			}
-			newSlice.Index(j).Set(destElem)
-		}
-		destField.Set(newSlice)
-	}
-	return nil
-}
-
-func mapSpecialTypes(sourceField reflect.Value, destField reflect.Value) error {
-	if _, ok := sourceField.Interface().(datatype.DateTime); ok {
-		if sourceField.Type() == reflect.TypeOf(datatype.DateTime{}) && destField.Type() == reflect.TypeOf(time.Time{}) {
-			dateValue := sourceField.Interface().(datatype.DateTime)
-			destField.Set(reflect.ValueOf(dateValue.ToTime()))
-		}
-	}
-	return nil
+func MapStruct(source any, destination any) error {
+	return copier.CopyWithOption(destination, source, copier.Option{
+		DeepCopy: true,
+	})
 }
diff --git a/backend/internal/dto/dto_mapper_test.go b/backend/internal/dto/dto_mapper_test.go
new file mode 100644
index 00000000..43b86b14
--- /dev/null
+++ b/backend/internal/dto/dto_mapper_test.go
@@ -0,0 +1,197 @@
+package dto
+
+import (
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	"github.com/pocket-id/pocket-id/backend/internal/model"
+	datatype "github.com/pocket-id/pocket-id/backend/internal/model/types"
+	"github.com/pocket-id/pocket-id/backend/internal/utils"
+)
+
+type sourceStruct struct {
+	AString            string
+	AStringPtr         *string
+	ABool              bool
+	ABoolPtr           *bool
+	ACustomDateTime    datatype.DateTime
+	ACustomDateTimePtr *datatype.DateTime
+	ANilStringPtr      *string
+	ASlice             []string
+	AMap               map[string]int
+	AStruct            embeddedStruct
+	AStructPtr         *embeddedStruct
+
+	StringPtrToString      *string
+	EmptyStringPtrToString *string
+	NilStringPtrToString   *string
+	IntToInt64             int
+	AuditLogEventToString  model.AuditLogEvent
+}
+
+type destStruct struct {
+	AString            string
+	AStringPtr         *string
+	ABool              bool
+	ABoolPtr           *bool
+	ACustomDateTime    datatype.DateTime
+	ACustomDateTimePtr *datatype.DateTime
+	ANilStringPtr      *string
+	ASlice             []string
+	AMap               map[string]int
+	AStruct            embeddedStruct
+	AStructPtr         *embeddedStruct
+
+	StringPtrToString      string
+	EmptyStringPtrToString string
+	NilStringPtrToString   string
+	IntToInt64             int64
+	AuditLogEventToString  string
+}
+
+type embeddedStruct struct {
+	Foo string
+	Bar int64
+}
+
+func TestMapStruct(t *testing.T) {
+	src := sourceStruct{
+		AString:            "abcd",
+		AStringPtr:         utils.Ptr("xyz"),
+		ABool:              true,
+		ABoolPtr:           utils.Ptr(false),
+		ACustomDateTime:    datatype.DateTime(time.Date(2025, 1, 2, 3, 4, 5, 0, time.UTC)),
+		ACustomDateTimePtr: utils.Ptr(datatype.DateTime(time.Date(2024, 1, 2, 3, 4, 5, 0, time.UTC))),
+		ANilStringPtr:      nil,
+		ASlice:             []string{"a", "b", "c"},
+		AMap: map[string]int{
+			"a": 1,
+			"b": 2,
+		},
+		AStruct: embeddedStruct{
+			Foo: "bar",
+			Bar: 42,
+		},
+		AStructPtr: &embeddedStruct{
+			Foo: "quo",
+			Bar: 111,
+		},
+
+		StringPtrToString:      utils.Ptr("foobar"),
+		EmptyStringPtrToString: utils.Ptr(""),
+		NilStringPtrToString:   nil,
+		IntToInt64:             99,
+		AuditLogEventToString:  model.AuditLogEventAccountCreated,
+	}
+	var dst destStruct
+	err := MapStruct(src, &dst)
+	require.NoError(t, err)
+
+	assert.Equal(t, src.AString, dst.AString)
+	_ = assert.NotNil(t, src.AStringPtr) &&
+		assert.Equal(t, *src.AStringPtr, *dst.AStringPtr)
+	assert.Equal(t, src.ABool, dst.ABool)
+	_ = assert.NotNil(t, src.ABoolPtr) &&
+		assert.Equal(t, *src.ABoolPtr, *dst.ABoolPtr)
+	assert.Equal(t, src.ACustomDateTime, dst.ACustomDateTime)
+	_ = assert.NotNil(t, src.ACustomDateTimePtr) &&
+		assert.Equal(t, *src.ACustomDateTimePtr, *dst.ACustomDateTimePtr)
+	assert.Nil(t, dst.ANilStringPtr)
+	assert.Equal(t, src.ASlice, dst.ASlice)
+	assert.Equal(t, src.AMap, dst.AMap)
+	assert.Equal(t, "bar", dst.AStruct.Foo)
+	assert.Equal(t, int64(42), dst.AStruct.Bar)
+	_ = assert.NotNil(t, src.AStructPtr) &&
+		assert.Equal(t, "quo", dst.AStructPtr.Foo) &&
+		assert.Equal(t, int64(111), dst.AStructPtr.Bar)
+	assert.Equal(t, "foobar", dst.StringPtrToString)
+	assert.Empty(t, dst.EmptyStringPtrToString)
+	assert.Empty(t, dst.NilStringPtrToString)
+	assert.Equal(t, int64(99), dst.IntToInt64)
+	assert.Equal(t, "ACCOUNT_CREATED", dst.AuditLogEventToString)
+}
+
+func TestMapStructList(t *testing.T) {
+	sources := []sourceStruct{
+		{
+			AString:            "first",
+			AStringPtr:         utils.Ptr("one"),
+			ABool:              true,
+			ABoolPtr:           utils.Ptr(false),
+			ACustomDateTime:    datatype.DateTime(time.Date(2025, 1, 2, 3, 4, 5, 0, time.UTC)),
+			ACustomDateTimePtr: utils.Ptr(datatype.DateTime(time.Date(2024, 1, 2, 3, 4, 5, 0, time.UTC))),
+			ASlice:             []string{"a", "b"},
+			AMap: map[string]int{
+				"a": 1,
+				"b": 2,
+			},
+			AStruct: embeddedStruct{
+				Foo: "first_struct",
+				Bar: 10,
+			},
+			IntToInt64: 10,
+		},
+		{
+			AString:            "second",
+			AStringPtr:         utils.Ptr("two"),
+			ABool:              false,
+			ABoolPtr:           utils.Ptr(true),
+			ACustomDateTime:    datatype.DateTime(time.Date(2026, 6, 7, 8, 9, 10, 0, time.UTC)),
+			ACustomDateTimePtr: utils.Ptr(datatype.DateTime(time.Date(2023, 6, 7, 8, 9, 10, 0, time.UTC))),
+			ASlice:             []string{"c", "d", "e"},
+			AMap: map[string]int{
+				"c": 3,
+				"d": 4,
+			},
+			AStruct: embeddedStruct{
+				Foo: "second_struct",
+				Bar: 20,
+			},
+			IntToInt64: 20,
+		},
+	}
+
+	var destinations []destStruct
+	err := MapStructList(sources, &destinations)
+
+	require.NoError(t, err)
+	require.Len(t, destinations, 2)
+
+	// Verify first element
+	assert.Equal(t, "first", destinations[0].AString)
+	assert.Equal(t, "one", *destinations[0].AStringPtr)
+	assert.True(t, destinations[0].ABool)
+	assert.False(t, *destinations[0].ABoolPtr)
+	assert.Equal(t, datatype.DateTime(time.Date(2025, 1, 2, 3, 4, 5, 0, time.UTC)), destinations[0].ACustomDateTime)
+	assert.Equal(t, datatype.DateTime(time.Date(2024, 1, 2, 3, 4, 5, 0, time.UTC)), *destinations[0].ACustomDateTimePtr)
+	assert.Equal(t, []string{"a", "b"}, destinations[0].ASlice)
+	assert.Equal(t, map[string]int{"a": 1, "b": 2}, destinations[0].AMap)
+	assert.Equal(t, "first_struct", destinations[0].AStruct.Foo)
+	assert.Equal(t, int64(10), destinations[0].AStruct.Bar)
+	assert.Equal(t, int64(10), destinations[0].IntToInt64)
+
+	// Verify second element
+	assert.Equal(t, "second", destinations[1].AString)
+	assert.Equal(t, "two", *destinations[1].AStringPtr)
+	assert.False(t, destinations[1].ABool)
+	assert.True(t, *destinations[1].ABoolPtr)
+	assert.Equal(t, datatype.DateTime(time.Date(2026, 6, 7, 8, 9, 10, 0, time.UTC)), destinations[1].ACustomDateTime)
+	assert.Equal(t, datatype.DateTime(time.Date(2023, 6, 7, 8, 9, 10, 0, time.UTC)), *destinations[1].ACustomDateTimePtr)
+	assert.Equal(t, []string{"c", "d", "e"}, destinations[1].ASlice)
+	assert.Equal(t, map[string]int{"c": 3, "d": 4}, destinations[1].AMap)
+	assert.Equal(t, "second_struct", destinations[1].AStruct.Foo)
+	assert.Equal(t, int64(20), destinations[1].AStruct.Bar)
+	assert.Equal(t, int64(20), destinations[1].IntToInt64)
+}
+
+func TestMapStructList_EmptySource(t *testing.T) {
+	var sources []sourceStruct
+	var destinations []destStruct
+
+	err := MapStructList(sources, &destinations)
+	require.NoError(t, err)
+	assert.Empty(t, destinations)
+}
diff --git a/backend/internal/dto/oidc_dto.go b/backend/internal/dto/oidc_dto.go
index f9cab715..22f8a805 100644
--- a/backend/internal/dto/oidc_dto.go
+++ b/backend/internal/dto/oidc_dto.go
@@ -149,7 +149,7 @@ type AuthorizedOidcClientDto struct {
 }
 
 type OidcClientPreviewDto struct {
-	IdToken     map[string]interface{} `json:"idToken"`
-	AccessToken map[string]interface{} `json:"accessToken"`
-	UserInfo    map[string]interface{} `json:"userInfo"`
+	IdToken     map[string]any `json:"idToken"`
+	AccessToken map[string]any `json:"accessToken"`
+	UserInfo    map[string]any `json:"userInfo"`
 }