diff --git a/backend/internal/bootstrap/bootstrap.go b/backend/internal/bootstrap/bootstrap.go
index 7fb4a8a9..cba2250b 100644
--- a/backend/internal/bootstrap/bootstrap.go
+++ b/backend/internal/bootstrap/bootstrap.go
@@ -27,7 +27,10 @@ func Bootstrap(ctx context.Context) error {
 	}
 
 	// Connect to the database
-	db := NewDatabase()
+	db, err := NewDatabase()
+	if err != nil {
+		return fmt.Errorf("failed to initialize database: %w", err)
+	}
 
 	// Create all services
 	svc, err := initServices(ctx, db, httpClient)
diff --git a/backend/internal/bootstrap/db_bootstrap.go b/backend/internal/bootstrap/db_bootstrap.go
index a3d08cfc..14e6bbe1 100644
--- a/backend/internal/bootstrap/db_bootstrap.go
+++ b/backend/internal/bootstrap/db_bootstrap.go
@@ -3,7 +3,6 @@ package bootstrap
 import (
 	"errors"
 	"fmt"
-	"log"
 	"log/slog"
 	"net/url"
 	"strings"
@@ -25,14 +24,14 @@ import (
 	"github.com/pocket-id/pocket-id/backend/resources"
 )
 
-func NewDatabase() (db *gorm.DB) {
-	db, err := connectDatabase()
+func NewDatabase() (db *gorm.DB, err error) {
+	db, err = connectDatabase()
 	if err != nil {
-		log.Fatalf("failed to connect to database: %v", err)
+		return nil, fmt.Errorf("failed to connect to database: %w", err)
 	}
 	sqlDb, err := db.DB()
 	if err != nil {
-		log.Fatalf("failed to get sql.DB: %v", err)
+		return nil, fmt.Errorf("failed to get sql.DB: %w", err)
 	}
 
 	// Choose the correct driver for the database provider
@@ -44,18 +43,18 @@ func NewDatabase() (db *gorm.DB) {
 		driver, err = postgresMigrate.WithInstance(sqlDb, &postgresMigrate.Config{})
 	default:
 		// Should never happen at this point
-		log.Fatalf("unsupported database provider: %s", common.EnvConfig.DbProvider)
+		return nil, fmt.Errorf("unsupported database provider: %s", common.EnvConfig.DbProvider)
 	}
 	if err != nil {
-		log.Fatalf("failed to create migration driver: %v", err)
+		return nil, fmt.Errorf("failed to create migration driver: %w", err)
 	}
 
 	// Run migrations
 	if err := migrateDatabase(driver); err != nil {
-		log.Fatalf("failed to run migrations: %v", err)
+		return nil, fmt.Errorf("failed to run migrations: %w", err)
 	}
 
-	return db
+	return db, nil
 }
 
 func migrateDatabase(driver database.Driver) error {
diff --git a/backend/internal/bootstrap/e2etest_router_bootstrap.go b/backend/internal/bootstrap/e2etest_router_bootstrap.go
index e16bdc9f..434ba223 100644
--- a/backend/internal/bootstrap/e2etest_router_bootstrap.go
+++ b/backend/internal/bootstrap/e2etest_router_bootstrap.go
@@ -3,7 +3,8 @@
 package bootstrap
 
 import (
-	"log"
+	"log/slog"
+	"os"
 
 	"github.com/gin-gonic/gin"
 	"gorm.io/gorm"
@@ -18,7 +19,8 @@ func init() {
 		func(apiGroup *gin.RouterGroup, db *gorm.DB, svc *services) {
 			testService, err := service.NewTestService(db, svc.appConfigService, svc.jwtService, svc.ldapService)
 			if err != nil {
-				log.Fatalf("failed to initialize test service: %v", err)
+				slog.Error("Failed to initialize test service", slog.Any("error", err))
+				os.Exit(1)
 				return
 			}
 
diff --git a/backend/internal/bootstrap/services_bootstrap.go b/backend/internal/bootstrap/services_bootstrap.go
index 8502b9bf..a379124f 100644
--- a/backend/internal/bootstrap/services_bootstrap.go
+++ b/backend/internal/bootstrap/services_bootstrap.go
@@ -29,7 +29,10 @@ type services struct {
 func initServices(ctx context.Context, db *gorm.DB, httpClient *http.Client) (svc *services, err error) {
 	svc = &services{}
 
-	svc.appConfigService = service.NewAppConfigService(ctx, db)
+	svc.appConfigService, err = service.NewAppConfigService(ctx, db)
+	if err != nil {
+		return nil, fmt.Errorf("failed to create app config service: %w", err)
+	}
 
 	svc.emailService, err = service.NewEmailService(db, svc.appConfigService)
 	if err != nil {
@@ -54,7 +57,11 @@ func initServices(ctx context.Context, db *gorm.DB, httpClient *http.Client) (sv
 	svc.userGroupService = service.NewUserGroupService(db, svc.appConfigService)
 	svc.ldapService = service.NewLdapService(db, httpClient, svc.appConfigService, svc.userService, svc.userGroupService)
 	svc.apiKeyService = service.NewApiKeyService(db, svc.emailService)
-	svc.webauthnService = service.NewWebAuthnService(db, svc.jwtService, svc.auditLogService, svc.appConfigService)
+
+	svc.webauthnService, err = service.NewWebAuthnService(db, svc.jwtService, svc.auditLogService, svc.appConfigService)
+	if err != nil {
+		return nil, fmt.Errorf("failed to create WebAuthn service: %w", err)
+	}
 
 	return svc, nil
 }
diff --git a/backend/internal/cmds/key_rotate.go b/backend/internal/cmds/key_rotate.go
index 5e29f7d3..1a219b7d 100644
--- a/backend/internal/cmds/key_rotate.go
+++ b/backend/internal/cmds/key_rotate.go
@@ -30,7 +30,10 @@ func init() {
 		Use:   "key-rotate",
 		Short: "Generates a new token signing key and replaces the current one",
 		RunE: func(cmd *cobra.Command, args []string) error {
-			db := bootstrap.NewDatabase()
+			db, err := bootstrap.NewDatabase()
+			if err != nil {
+				return err
+			}
 
 			return keyRotate(cmd.Context(), flags, db, &common.EnvConfig)
 		},
@@ -80,7 +83,10 @@ func keyRotate(ctx context.Context, flags keyRotateFlags, db *gorm.DB, envConfig
 	}
 
 	// Init the services we need
-	appConfigService := service.NewAppConfigService(ctx, db)
+	appConfigService, err := service.NewAppConfigService(ctx, db)
+	if err != nil {
+		return fmt.Errorf("failed to create app config service: %w", err)
+	}
 
 	// Get the key provider
 	keyProvider, err := jwkutils.GetKeyProvider(db, envConfig, appConfigService.GetDbConfig().InstanceID.Value)
diff --git a/backend/internal/cmds/key_rotate_test.go b/backend/internal/cmds/key_rotate_test.go
index cd020a34..e7ecd47f 100644
--- a/backend/internal/cmds/key_rotate_test.go
+++ b/backend/internal/cmds/key_rotate_test.go
@@ -97,7 +97,8 @@ func testKeyRotateWithFileStorage(t *testing.T, flags keyRotateFlags, wantErr bo
 	db := testingutils.NewDatabaseForTest(t)
 
 	// Initialize app config service and create instance
-	appConfigService := service.NewAppConfigService(t.Context(), db)
+	appConfigService, err := service.NewAppConfigService(t.Context(), db)
+	require.NoError(t, err)
 	instanceID := appConfigService.GetDbConfig().InstanceID.Value
 
 	// Check if key exists before rotation
@@ -147,7 +148,8 @@ func testKeyRotateWithDatabaseStorage(t *testing.T, flags keyRotateFlags, wantEr
 	db := testingutils.NewDatabaseForTest(t)
 
 	// Initialize app config service and create instance
-	appConfigService := service.NewAppConfigService(t.Context(), db)
+	appConfigService, err := service.NewAppConfigService(t.Context(), db)
+	require.NoError(t, err)
 	instanceID := appConfigService.GetDbConfig().InstanceID.Value
 
 	// Get key provider
diff --git a/backend/internal/cmds/one_time_access_token.go b/backend/internal/cmds/one_time_access_token.go
index 65b94e87..6b9804a5 100644
--- a/backend/internal/cmds/one_time_access_token.go
+++ b/backend/internal/cmds/one_time_access_token.go
@@ -24,11 +24,14 @@ var oneTimeAccessTokenCmd = &cobra.Command{
 		userArg := args[0]
 
 		// Connect to the database
-		db := bootstrap.NewDatabase()
+		db, err := bootstrap.NewDatabase()
+		if err != nil {
+			return err
+		}
 
 		// Create the access token
 		var oneTimeAccessToken *model.OneTimeAccessToken
-		err := db.Transaction(func(tx *gorm.DB) error {
+		err = db.Transaction(func(tx *gorm.DB) error {
 			// Load the user to retrieve the user ID
 			var user model.User
 			queryCtx, queryCancel := context.WithTimeout(cmd.Context(), 10*time.Second)
diff --git a/backend/internal/common/env_config.go b/backend/internal/common/env_config.go
index 1ec0eb3d..17528865 100644
--- a/backend/internal/common/env_config.go
+++ b/backend/internal/common/env_config.go
@@ -3,8 +3,9 @@ package common
 import (
 	"errors"
 	"fmt"
-	"log"
+	"log/slog"
 	"net/url"
+	"os"
 
 	"github.com/caarlos0/env/v11"
 	_ "github.com/joho/godotenv/autoload"
@@ -57,7 +58,8 @@ var EnvConfig = defaultConfig()
 func init() {
 	err := parseEnvConfig()
 	if err != nil {
-		log.Fatalf("Configuration error: %v", err)
+		slog.Error("Configuration error", slog.Any("error", err))
+		os.Exit(1)
 	}
 }
 
diff --git a/backend/internal/controller/e2etest_controller.go b/backend/internal/controller/e2etest_controller.go
index 4e5e791c..54d74e2c 100644
--- a/backend/internal/controller/e2etest_controller.go
+++ b/backend/internal/controller/e2etest_controller.go
@@ -40,7 +40,7 @@ func (tc *TestController) resetAndSeedHandler(c *gin.Context) {
 		return
 	}
 
-	if err := tc.TestService.ResetApplicationImages(); err != nil {
+	if err := tc.TestService.ResetApplicationImages(c.Request.Context()); err != nil {
 		_ = c.Error(err)
 		return
 	}
diff --git a/backend/internal/controller/well_known_controller.go b/backend/internal/controller/well_known_controller.go
index e8f01746..4d5a2cf2 100644
--- a/backend/internal/controller/well_known_controller.go
+++ b/backend/internal/controller/well_known_controller.go
@@ -3,8 +3,9 @@ package controller
 import (
 	"encoding/json"
 	"fmt"
-	"log"
+	"log/slog"
 	"net/http"
+	"os"
 
 	"github.com/gin-gonic/gin"
 
@@ -23,7 +24,9 @@ func NewWellKnownController(group *gin.RouterGroup, jwtService *service.JwtServi
 	var err error
 	wkc.oidcConfig, err = wkc.computeOIDCConfiguration()
 	if err != nil {
-		log.Fatalf("Failed to pre-compute OpenID Connect configuration document: %v", err)
+		slog.Error("Failed to pre-compute OpenID Connect configuration document", slog.Any("error", err))
+		os.Exit(1)
+		return
 	}
 
 	group.GET("/.well-known/jwks.json", wkc.jwksHandler)
diff --git a/backend/internal/dto/validations.go b/backend/internal/dto/validations.go
index 1313c9b9..b98ac27d 100644
--- a/backend/internal/dto/validations.go
+++ b/backend/internal/dto/validations.go
@@ -1,7 +1,8 @@
 package dto
 
 import (
-	"log"
+	"log/slog"
+	"os"
 	"regexp"
 
 	"github.com/gin-gonic/gin/binding"
@@ -18,9 +19,11 @@ var validateUsername validator.Func = func(fl validator.FieldLevel) bool {
 }
 
 func init() {
-	if v, ok := binding.Validator.Engine().(*validator.Validate); ok {
-		if err := v.RegisterValidation("username", validateUsername); err != nil {
-			log.Fatalf("Failed to register custom validation: %v", err)
-		}
+	v, _ := binding.Validator.Engine().(*validator.Validate)
+	err := v.RegisterValidation("username", validateUsername)
+	if err != nil {
+		slog.Error("Failed to register custom validation", slog.Any("error", err))
+		os.Exit(1)
+		return
 	}
 }
diff --git a/backend/internal/service/app_config_service.go b/backend/internal/service/app_config_service.go
index 7df3c9bc..81422e44 100644
--- a/backend/internal/service/app_config_service.go
+++ b/backend/internal/service/app_config_service.go
@@ -4,7 +4,6 @@ import (
 	"context"
 	"errors"
 	"fmt"
-	"log"
 	"mime/multipart"
 	"os"
 	"reflect"
@@ -28,22 +27,22 @@ type AppConfigService struct {
 	db       *gorm.DB
 }
 
-func NewAppConfigService(ctx context.Context, db *gorm.DB) *AppConfigService {
+func NewAppConfigService(ctx context.Context, db *gorm.DB) (*AppConfigService, error) {
 	service := &AppConfigService{
 		db: db,
 	}
 
 	err := service.LoadDbConfig(ctx)
 	if err != nil {
-		log.Fatalf("Failed to initialize app config service: %v", err)
+		return nil, fmt.Errorf("failed to initialize app config service: %w", err)
 	}
 
 	err = service.initInstanceID(ctx)
 	if err != nil {
-		log.Fatalf("Failed to initialize instance ID: %v", err)
+		return nil, fmt.Errorf("failed to initialize instance ID: %w", err)
 	}
 
-	return service
+	return service, nil
 }
 
 // GetDbConfig returns the application configuration.
diff --git a/backend/internal/service/audit_log_service.go b/backend/internal/service/audit_log_service.go
index 3f31d5ca..fb5ceec7 100644
--- a/backend/internal/service/audit_log_service.go
+++ b/backend/internal/service/audit_log_service.go
@@ -22,7 +22,12 @@ type AuditLogService struct {
 }
 
 func NewAuditLogService(db *gorm.DB, appConfigService *AppConfigService, emailService *EmailService, geoliteService *GeoLiteService) *AuditLogService {
-	return &AuditLogService{db: db, appConfigService: appConfigService, emailService: emailService, geoliteService: geoliteService}
+	return &AuditLogService{
+		db:               db,
+		appConfigService: appConfigService,
+		emailService:     emailService,
+		geoliteService:   geoliteService,
+	}
 }
 
 // Create creates a new audit log entry in the database
diff --git a/backend/internal/service/e2etest_service.go b/backend/internal/service/e2etest_service.go
index b7632e3a..9043a954 100644
--- a/backend/internal/service/e2etest_service.go
+++ b/backend/internal/service/e2etest_service.go
@@ -10,7 +10,7 @@ import (
 	"crypto/x509"
 	"encoding/base64"
 	"fmt"
-	"log"
+	"log/slog"
 	"os"
 	"path/filepath"
 	"time"
@@ -402,9 +402,9 @@ func (s *TestService) ResetDatabase() error {
 	return err
 }
 
-func (s *TestService) ResetApplicationImages() error {
+func (s *TestService) ResetApplicationImages(ctx context.Context) error {
 	if err := os.RemoveAll(common.EnvConfig.UploadPath); err != nil {
-		log.Printf("Error removing directory: %v", err)
+		slog.ErrorContext(ctx, "Error removing directory", slog.Any("error", err))
 		return err
 	}
 
diff --git a/backend/internal/service/geolite_service.go b/backend/internal/service/geolite_service.go
index fdc87c0a..3ce847e4 100644
--- a/backend/internal/service/geolite_service.go
+++ b/backend/internal/service/geolite_service.go
@@ -57,7 +57,8 @@ func NewGeoLiteService(httpClient *http.Client) *GeoLiteService {
 	}
 
 	// Initialize IPv6 local ranges
-	if err := service.initializeIPv6LocalRanges(); err != nil {
+	err := service.initializeIPv6LocalRanges()
+	if err != nil {
 		slog.Warn("Failed to initialize IPv6 local ranges", slog.Any("error", err))
 	}
 
diff --git a/backend/internal/service/ldap_service.go b/backend/internal/service/ldap_service.go
index 52ff9ffd..9567503c 100644
--- a/backend/internal/service/ldap_service.go
+++ b/backend/internal/service/ldap_service.go
@@ -8,7 +8,6 @@ import (
 	"errors"
 	"fmt"
 	"io"
-	"log"
 	"log/slog"
 	"net/http"
 	"net/url"
@@ -169,13 +168,13 @@ func (s *LdapService) SyncGroups(ctx context.Context, tx *gorm.DB, client *ldap.
 
 				userResult, err := client.Search(userSearchReq)
 				if err != nil || len(userResult.Entries) == 0 {
-					log.Printf("Could not resolve group member DN '%s': %v", member, err)
+					slog.WarnContext(ctx, "Could not resolve group member DN", slog.String("member", member), slog.Any("error", err))
 					continue
 				}
 
 				username = userResult.Entries[0].GetAttributeValue(dbConfig.LdapAttributeUserUsername.Value)
 				if username == "" {
-					log.Printf("Could not extract username from group member DN '%s'", member)
+					slog.WarnContext(ctx, "Could not extract username from group member DN", slog.String("member", member))
 					continue
 				}
 			}
diff --git a/backend/internal/service/oidc_service.go b/backend/internal/service/oidc_service.go
index fadfc68a..209837c0 100644
--- a/backend/internal/service/oidc_service.go
+++ b/backend/internal/service/oidc_service.go
@@ -8,7 +8,6 @@ import (
 	"encoding/json"
 	"errors"
 	"fmt"
-	"log"
 	"log/slog"
 	"mime/multipart"
 	"net/http"
@@ -1180,9 +1179,13 @@ func (s *OidcService) VerifyDeviceCode(ctx context.Context, userCode string, use
 	}()
 
 	var deviceAuth model.OidcDeviceCode
-	if err := tx.WithContext(ctx).Preload("Client.AllowedUserGroups").First(&deviceAuth, "user_code = ?", userCode).Error; err != nil {
-		log.Printf("Error finding device code with user_code %s: %v", userCode, err)
-		return err
+	err := tx.
+		WithContext(ctx).
+		Preload("Client.AllowedUserGroups").
+		First(&deviceAuth, "user_code = ?", userCode).
+		Error
+	if err != nil {
+		return fmt.Errorf("error finding device code: %w", err)
 	}
 
 	if time.Now().After(deviceAuth.ExpiresAt.ToTime()) {
@@ -1191,17 +1194,26 @@ func (s *OidcService) VerifyDeviceCode(ctx context.Context, userCode string, use
 
 	// Check if the user group is allowed to authorize the client
 	var user model.User
-	if err := tx.WithContext(ctx).Preload("UserGroups").First(&user, "id = ?", userID).Error; err != nil {
-		return err
+	err = tx.
+		WithContext(ctx).
+		Preload("UserGroups").
+		First(&user, "id = ?", userID).
+		Error
+	if err != nil {
+		return fmt.Errorf("error finding user groups: %w", err)
 	}
 
 	if !s.IsUserGroupAllowedToAuthorize(user, deviceAuth.Client) {
 		return &common.OidcAccessDeniedError{}
 	}
 
-	if err := tx.WithContext(ctx).Preload("Client").First(&deviceAuth, "user_code = ?", userCode).Error; err != nil {
-		log.Printf("Error finding device code with user_code %s: %v", userCode, err)
-		return err
+	err = tx.
+		WithContext(ctx).
+		Preload("Client").
+		First(&deviceAuth, "user_code = ?", userCode).
+		Error
+	if err != nil {
+		return fmt.Errorf("error finding device code: %w", err)
 	}
 
 	if time.Now().After(deviceAuth.ExpiresAt.ToTime()) {
@@ -1211,16 +1223,12 @@ func (s *OidcService) VerifyDeviceCode(ctx context.Context, userCode string, use
 	deviceAuth.UserID = &userID
 	deviceAuth.IsAuthorized = true
 
-	if err := tx.WithContext(ctx).Save(&deviceAuth).Error; err != nil {
-		log.Printf("Error saving device auth: %v", err)
-		return err
-	}
-
-	// Verify the update was successful
-	var verifiedAuth model.OidcDeviceCode
-	if err := tx.WithContext(ctx).First(&verifiedAuth, "device_code = ?", deviceAuth.DeviceCode).Error; err != nil {
-		log.Printf("Error verifying update: %v", err)
-		return err
+	err = tx.
+		WithContext(ctx).
+		Save(&deviceAuth).
+		Error
+	if err != nil {
+		return fmt.Errorf("error saving device auth: %w", err)
 	}
 
 	// Create user authorization if needed
@@ -1229,15 +1237,16 @@ func (s *OidcService) VerifyDeviceCode(ctx context.Context, userCode string, use
 		return err
 	}
 
+	auditLogData := model.AuditLogData{"clientName": deviceAuth.Client.Name}
 	if !hasAuthorizedClient {
-		err := s.createAuthorizedClientInternal(ctx, userID, deviceAuth.ClientID, deviceAuth.Scope, tx)
+		err = s.createAuthorizedClientInternal(ctx, userID, deviceAuth.ClientID, deviceAuth.Scope, tx)
 		if err != nil {
 			return err
 		}
 
-		s.auditLogService.Create(ctx, model.AuditLogEventNewDeviceCodeAuthorization, ipAddress, userAgent, userID, model.AuditLogData{"clientName": deviceAuth.Client.Name}, tx)
+		s.auditLogService.Create(ctx, model.AuditLogEventNewDeviceCodeAuthorization, ipAddress, userAgent, userID, auditLogData, tx)
 	} else {
-		s.auditLogService.Create(ctx, model.AuditLogEventDeviceCodeAuthorization, ipAddress, userAgent, userID, model.AuditLogData{"clientName": deviceAuth.Client.Name}, tx)
+		s.auditLogService.Create(ctx, model.AuditLogEventDeviceCodeAuthorization, ipAddress, userAgent, userID, auditLogData, tx)
 	}
 
 	return tx.Commit().Error
@@ -1428,7 +1437,7 @@ func (s *OidcService) verifyClientCredentialsInternal(ctx context.Context, tx *g
 	case isClientAssertion:
 		err = s.verifyClientAssertionFromFederatedIdentities(ctx, client, input)
 		if err != nil {
-			log.Printf("Invalid assertion for client '%s': %v", client.ID, err)
+			slog.WarnContext(ctx, "Invalid assertion for client", slog.String("client", client.ID), slog.Any("error", err))
 			return nil, &common.OidcClientAssertionInvalidError{}
 		}
 		return client, nil
diff --git a/backend/internal/service/user_service.go b/backend/internal/service/user_service.go
index 30527fd8..1ed1795c 100644
--- a/backend/internal/service/user_service.go
+++ b/backend/internal/service/user_service.go
@@ -6,7 +6,6 @@ import (
 	"errors"
 	"fmt"
 	"io"
-	"log"
 	"log/slog"
 	"net/url"
 	"os"
@@ -35,7 +34,13 @@ type UserService struct {
 }
 
 func NewUserService(db *gorm.DB, jwtService *JwtService, auditLogService *AuditLogService, emailService *EmailService, appConfigService *AppConfigService) *UserService {
-	return &UserService{db: db, jwtService: jwtService, auditLogService: auditLogService, emailService: emailService, appConfigService: appConfigService}
+	return &UserService{
+		db:               db,
+		jwtService:       jwtService,
+		auditLogService:  auditLogService,
+		emailService:     emailService,
+		appConfigService: appConfigService,
+	}
 }
 
 func (s *UserService) ListUsers(ctx context.Context, searchTerm string, sortedPaginationRequest utils.SortedPaginationRequest) ([]model.User, utils.PaginationResponse, error) {
@@ -47,7 +52,8 @@ func (s *UserService) ListUsers(ctx context.Context, searchTerm string, sortedPa
 
 	if searchTerm != "" {
 		searchPattern := "%" + searchTerm + "%"
-		query = query.Where("email LIKE ? OR first_name LIKE ? OR last_name LIKE ? OR username LIKE ?",
+		query = query.Where(
+			"email LIKE ? OR first_name LIKE ? OR last_name LIKE ? OR username LIKE ?",
 			searchPattern, searchPattern, searchPattern, searchPattern)
 	}
 
@@ -120,13 +126,14 @@ func (s *UserService) GetProfilePicture(ctx context.Context, userID string) (io.
 	defaultPictureBytes := defaultPicture.Bytes()
 	go func() {
 		// Ensure the directory exists
-		err = os.MkdirAll(defaultProfilePicturesDir, os.ModePerm)
-		if err != nil {
-			log.Printf("Failed to create directory for default profile picture: %v", err)
+		errInternal := os.MkdirAll(defaultProfilePicturesDir, os.ModePerm)
+		if errInternal != nil {
+			slog.Error("Failed to create directory for default profile picture", slog.Any("error", errInternal))
 			return
 		}
-		if err := utils.SaveFileStream(bytes.NewReader(defaultPictureBytes), defaultPicturePath); err != nil {
-			log.Printf("Failed to cache default profile picture for initials %s: %v", user.Initials(), err)
+		errInternal = utils.SaveFileStream(bytes.NewReader(defaultPictureBytes), defaultPicturePath)
+		if errInternal != nil {
+			slog.Error("Failed to cache default profile picture for initials", slog.String("initials", user.Initials()), slog.Any("error", errInternal))
 		}
 	}()
 
diff --git a/backend/internal/service/webauthn_service.go b/backend/internal/service/webauthn_service.go
index a12e5278..e6f26e71 100644
--- a/backend/internal/service/webauthn_service.go
+++ b/backend/internal/service/webauthn_service.go
@@ -25,8 +25,8 @@ type WebAuthnService struct {
 	appConfigService *AppConfigService
 }
 
-func NewWebAuthnService(db *gorm.DB, jwtService *JwtService, auditLogService *AuditLogService, appConfigService *AppConfigService) *WebAuthnService {
-	webauthnConfig := &webauthn.Config{
+func NewWebAuthnService(db *gorm.DB, jwtService *JwtService, auditLogService *AuditLogService, appConfigService *AppConfigService) (*WebAuthnService, error) {
+	wa, err := webauthn.New(&webauthn.Config{
 		RPDisplayName: appConfigService.GetDbConfig().AppName.Value,
 		RPID:          utils.GetHostnameFromURL(common.EnvConfig.AppURL),
 		RPOrigins:     []string{common.EnvConfig.AppURL},
@@ -45,15 +45,18 @@ func NewWebAuthnService(db *gorm.DB, jwtService *JwtService, auditLogService *Au
 				TimeoutUVD: time.Second * 60,
 			},
 		},
+	})
+	if err != nil {
+		return nil, fmt.Errorf("failed to init webauthn object: %w", err)
 	}
-	wa, _ := webauthn.New(webauthnConfig)
+
 	return &WebAuthnService{
 		db:               db,
 		webAuthn:         wa,
 		jwtService:       jwtService,
 		auditLogService:  auditLogService,
 		appConfigService: appConfigService,
-	}
+	}, nil
 }
 
 func (s *WebAuthnService) BeginRegistration(ctx context.Context, userID string) (*model.PublicKeyCredentialCreationOptions, error) {
diff --git a/backend/internal/utils/aaguid_util.go b/backend/internal/utils/aaguid_util.go
index e2611a70..2c25bf24 100644
--- a/backend/internal/utils/aaguid_util.go
+++ b/backend/internal/utils/aaguid_util.go
@@ -4,7 +4,7 @@ import (
 	"encoding/hex"
 	"encoding/json"
 	"fmt"
-	"log"
+	"log/slog"
 	"sync"
 
 	"github.com/pocket-id/pocket-id/backend/resources"
@@ -57,12 +57,13 @@ func loadAAGUIDsFromFile() {
 	// Read from embedded file system
 	data, err := resources.FS.ReadFile("aaguids.json")
 	if err != nil {
-		log.Printf("Error reading embedded AAGUID file: %v", err)
+		slog.Error("Error reading embedded AAGUID file", slog.Any("error", err))
 		return
 	}
 
-	if err := json.Unmarshal(data, &aaguidMap); err != nil {
-		log.Printf("Error unmarshalling AAGUID data: %v", err)
+	err = json.Unmarshal(data, &aaguidMap)
+	if err != nil {
+		slog.Error("Error unmarshalling AAGUID data", slog.Any("error", err))
 		return
 	}
 }
diff --git a/backend/internal/utils/image/profile_picture.go b/backend/internal/utils/image/profile_picture.go
index 0bbba5ea..63e531f6 100644
--- a/backend/internal/utils/image/profile_picture.go
+++ b/backend/internal/utils/image/profile_picture.go
@@ -29,9 +29,9 @@ func CreateProfilePicture(file io.Reader) (io.Reader, error) {
 
 	pr, pw := io.Pipe()
 	go func() {
-		err = imaging.Encode(pw, img, imaging.PNG)
-		if err != nil {
-			_ = pw.CloseWithError(fmt.Errorf("failed to encode image: %w", err))
+		innerErr := imaging.Encode(pw, img, imaging.PNG)
+		if innerErr != nil {
+			_ = pw.CloseWithError(fmt.Errorf("failed to encode image: %w", innerErr))
 			return
 		}
 		pw.Close()
diff --git a/backend/internal/utils/signals/signal.go b/backend/internal/utils/signals/signal.go
index fe2e7251..8699216b 100644
--- a/backend/internal/utils/signals/signal.go
+++ b/backend/internal/utils/signals/signal.go
@@ -2,7 +2,7 @@ package signals
 
 import (
 	"context"
-	"log"
+	"log/slog"
 	"os"
 	"os/signal"
 	"syscall"
@@ -28,11 +28,11 @@ func SignalContext(parentCtx context.Context) context.Context {
 	signal.Notify(sigCh, os.Interrupt, syscall.SIGTERM)
 	go func() {
 		<-sigCh
-		log.Println("Received interrupt signal. Shutting down…")
+		slog.Info("Received interrupt signal. Shutting down…")
 		cancel()
 
 		<-sigCh
-		log.Println("Received a second interrupt signal. Forcing an immediate shutdown.")
+		slog.Warn("Received a second interrupt signal. Forcing an immediate shutdown.")
 		os.Exit(1)
 	}()