diff --git a/.env.example b/.env.example
index b521369..ec81394 100644
--- a/.env.example
+++ b/.env.example
@@ -1,3 +1,7 @@
+# General Config
+# ##############
+LOG_LEVEL=INFO # can be DEBUG, INFO, WARN, ERROR
+
 # Prober config
 # #############
 SERVER_ENDPOINT="http://127.0.0.1:18901"
@@ -8,9 +12,7 @@ TOR_SOCKS="127.0.0.1:9050"
 # Server Config
 # #############
 SECRET_KEY="" # must be 32 char length, use `openssl rand -base64 32` to generate random secret
-LOG_LEVEL=INFO # can be DEBUG, INFO, WARNING, ERROR
 # Fiber Config
-APP_DEBUG=false # if this set to true , LOG_LEVEL will be set to DEBUG
 APP_PREFORK=true
 APP_HOST="127.0.0.1"
 APP_PORT=18090
@@ -21,4 +23,4 @@ DB_HOST=127.0.0.1
 DB_PORT=3306
 DB_USER=root
 DB_PASSWORD=
-DB_NAME=wa_ditatombot
+DB_NAME=xmr_nodes
diff --git a/README.md b/README.md
index 5f27dd7..e60cfc8 100644
--- a/README.md
+++ b/README.md
@@ -4,7 +4,9 @@ Source code of [https://xmr.ditatompel.com](https://xmr.ditatompel.com).
 
 ## Requirements
 
+- Go >= 1.22
 - Linux Machine (AMD64 or ARM64)
+- MySQL/MariaDB (for server)
 - [GeoIP Database](https://dev.maxmind.com/geoip/geoip2/geolite2/) (for server, optional). Place it to `./assets/geoip`, see [./internal/repo/geoip.go](./internal/repo/geoip.go).
 
 ## Installation
diff --git a/cmd/probe.go b/cmd/probe.go
index 7ca48f8..6212845 100644
--- a/cmd/probe.go
+++ b/cmd/probe.go
@@ -7,6 +7,7 @@ import (
 	"errors"
 	"fmt"
 	"io"
+	"log/slog"
 	"net"
 	"net/http"
 	"os"
@@ -47,7 +48,6 @@ func runProbe() {
 		fmt.Println("Please set SERVER_ENDPOINT in .env")
 		os.Exit(1)
 	}
-	fmt.Printf("Accept Tor: %t\n", cfg.AcceptTor)
 
 	if cfg.AcceptTor && cfg.TorSocks == "" {
 		fmt.Println("Please set TOR_SOCKS in .env")
@@ -58,16 +58,16 @@ func runProbe() {
 
 	node, err := probe.getJob()
 	if err != nil {
-		fmt.Println(err)
+		slog.Error(fmt.Sprintf("[PROBE] getJob: %s", err.Error()))
 		os.Exit(1)
 	}
 
 	fetchNode, err := probe.fetchNode(node)
 	if err != nil {
-		fmt.Println(err)
+		slog.Error(fmt.Sprintf("[PROBE] fetchNode: %s", err.Error()))
 		os.Exit(1)
 	}
-	fmt.Println(prettyPrint(fetchNode))
+	slog.Debug(fmt.Sprintf("[PROBE] fetchNode: %s", prettyPrint(fetchNode)))
 }
 
 func (p *proberClient) getJob() (repo.MoneroNode, error) {
@@ -79,6 +79,7 @@ func (p *proberClient) getJob() (repo.MoneroNode, error) {
 	node := repo.MoneroNode{}
 
 	endpoint := fmt.Sprintf("%s/api/v1/job%s", p.config.ServerEndpoint, queryParams)
+	slog.Info(fmt.Sprintf("[PROBE] Getting node from %s", endpoint))
 
 	req, err := http.NewRequest(http.MethodGet, endpoint, nil)
 	if err != nil {
@@ -108,6 +109,7 @@ func (p *proberClient) getJob() (repo.MoneroNode, error) {
 	}
 
 	node = response.Data
+	slog.Info(fmt.Sprintf("[PROBE] Got node: %s://%s:%d", node.Protocol, node.Hostname, node.Port))
 
 	return node, nil
 }
@@ -116,6 +118,8 @@ func (p *proberClient) fetchNode(node repo.MoneroNode) (repo.MoneroNode, error)
 	startTime := time.Now()
 	endpoint := fmt.Sprintf("%s://%s:%d/json_rpc", node.Protocol, node.Hostname, node.Port)
 	rpcParam := []byte(`{"jsonrpc": "2.0","id": "0","method": "get_info"}`)
+	slog.Info(fmt.Sprintf("[PROBE] Fetching node info from %s", endpoint))
+	slog.Debug(fmt.Sprintf("[PROBE] RPC param: %s", string(rpcParam)))
 
 	req, err := http.NewRequest(http.MethodPost, endpoint, bytes.NewBuffer(rpcParam))
 	if err != nil {
@@ -238,8 +242,7 @@ func (p *proberClient) fetchNode(node repo.MoneroNode) (repo.MoneroNode, error)
 	tookTime := time.Since(startTime).Seconds()
 	node.EstimateFee = feeEstimate.Result.Fee
 
-	fmt.Printf("Took %f seconds\n", tookTime)
-
+	slog.Info(fmt.Sprintf("[PROBE] Took %f seconds", tookTime))
 	if err := p.reportResult(node, tookTime); err != nil {
 		return node, err
 	}
diff --git a/cmd/root.go b/cmd/root.go
index faace09..b00cbf6 100644
--- a/cmd/root.go
+++ b/cmd/root.go
@@ -9,8 +9,6 @@ import (
 
 const AppVer = "0.0.1"
 
-var LogLevel string
-
 var rootCmd = &cobra.Command{
 	Use:     "xmr-nodes",
 	Short:   "XMR Nodes",
@@ -26,5 +24,4 @@ func Execute() {
 
 func init() {
 	config.LoadAll(".env")
-	LogLevel = config.AppCfg().LogLevel
 }
diff --git a/cmd/serve.go b/cmd/serve.go
index 45d60eb..a06b208 100644
--- a/cmd/serve.go
+++ b/cmd/serve.go
@@ -2,6 +2,7 @@ package cmd
 
 import (
 	"fmt"
+	"log/slog"
 	"os"
 	"os/signal"
 	"syscall"
@@ -49,12 +50,13 @@ func serve() {
 	app := fiber.New(fiberConfig())
 
 	// recover
-	app.Use(recover.New(recover.Config{EnableStackTrace: appCfg.Debug}))
+	app.Use(recover.New(recover.Config{EnableStackTrace: true}))
 
 	// logger middleware
-	if appCfg.Debug {
+	if appCfg.LogLevel == "DEBUG" {
 		app.Use(logger.New(logger.Config{
-			Format: "[${time}] ${status} - ${latency} ${method} ${path} ${queryParams} ${ip} ${ua}\n",
+			Format:     "${time} DEBUG [HTTP] ${status} - ${latency} ${method} ${path} ${queryParams} ${ip} ${ua}\n",
+			TimeFormat: "2006/01/02 15:04:05",
 		}))
 	}
 
@@ -88,14 +90,14 @@ func serve() {
 	go func() {
 		// capture sigterm and other system call here
 		<-sigCh
-		fmt.Println("Shutting down HTTP server...")
+		slog.Info("Shutting down HTTP server...")
 		_ = app.Shutdown()
 	}()
 
 	// start http server
 	serverAddr := fmt.Sprintf("%s:%d", appCfg.Host, appCfg.Port)
 	if err := app.Listen(serverAddr); err != nil {
-		fmt.Printf("Server is not running! error: %v", err)
+		slog.Error(fmt.Sprintf("Server is not running! error: %v", err))
 	}
 }
 
diff --git a/internal/config/app.go b/internal/config/app.go
index 8c535bb..8db273d 100644
--- a/internal/config/app.go
+++ b/internal/config/app.go
@@ -1,20 +1,21 @@
 package config
 
 import (
+	"log/slog"
 	"os"
 	"strconv"
 )
 
 type App struct {
+	// general config
+	LogLevel string
 	// configuration for server
-	Debug       bool
 	Prefork     bool
 	Host        string
 	Port        int
 	ProxyHeader string
 	AllowOrigin string
 	SecretKey   string
-	LogLevel    string
 	// configuration for prober (client)
 	ServerEndpoint string
 	ApiKey         string
@@ -30,21 +31,27 @@ func AppCfg() *App {
 
 // loads App configuration
 func LoadApp() {
+	// general config
+	app.LogLevel = os.Getenv("LOG_LEVEL")
+	switch app.LogLevel {
+	case "DEBUG":
+		slog.SetLogLoggerLevel(slog.LevelDebug)
+	case "ERROR":
+		slog.SetLogLoggerLevel(slog.LevelError)
+	case "WARN":
+		slog.SetLogLoggerLevel(slog.LevelWarn)
+	default:
+		slog.SetLogLoggerLevel(slog.LevelInfo)
+	}
+
 	// server configuration
 	app.Host = os.Getenv("APP_HOST")
 	app.Port, _ = strconv.Atoi(os.Getenv("APP_PORT"))
-	app.Debug, _ = strconv.ParseBool(os.Getenv("APP_DEBUG"))
 	app.Prefork, _ = strconv.ParseBool(os.Getenv("APP_PREFORK"))
 	app.ProxyHeader = os.Getenv("APP_PROXY_HEADER")
 	app.AllowOrigin = os.Getenv("APP_ALLOW_ORIGIN")
 	app.SecretKey = os.Getenv("SECRET_KEY")
-	app.LogLevel = os.Getenv("LOG_LEVEL")
-	if app.LogLevel == "" {
-		app.LogLevel = "INFO"
-	}
-	if app.Debug {
-		app.LogLevel = "DEBUG"
-	}
+
 	// prober configuration
 	app.ServerEndpoint = os.Getenv("SERVER_ENDPOINT")
 	app.ApiKey = os.Getenv("API_KEY")
diff --git a/internal/database/schema.go b/internal/database/schema.go
index 99c26f0..abc0a7d 100644
--- a/internal/database/schema.go
+++ b/internal/database/schema.go
@@ -2,6 +2,7 @@ package database
 
 import (
 	"fmt"
+	"log/slog"
 )
 
 type migrateFn func(*DB) error
@@ -11,11 +12,11 @@ var dbMigrate = [...]migrateFn{v1}
 func MigrateDb(db *DB) error {
 	version := getSchemaVersion(db)
 	if version < 0 {
-		return fmt.Errorf("can't get database schema version")
+		return fmt.Errorf("[DB] can't get database schema version")
 	} else if version == 0 {
-		fmt.Println("No database schema version found, creating schema version 1")
+		slog.Warn("[DB] No database schema version found, creating schema version 1")
 	} else {
-		fmt.Println("Database schema version:", version)
+		slog.Info(fmt.Sprintf("[DB] Current database schema version: %d", version))
 	}
 
 	for ; version < len(dbMigrate); version++ {
@@ -25,7 +26,7 @@ func MigrateDb(db *DB) error {
 		}
 
 		migrateFn := dbMigrate[version]
-		fmt.Println("Migrating database schema version:", version+1)
+		slog.Info(fmt.Sprintf("[DB] Migrating database schema version %d", version+1))
 
 		if err := migrateFn(db); err != nil {
 			tx.Rollback()
@@ -64,7 +65,9 @@ func setSchemaVersion(db *DB, version int) error {
 }
 
 func v1(db *DB) error {
+	slog.Debug("[DB] Migrating database schema version 1")
 	// table: tbl_admin
+	slog.Debug("[DB] Creating table: tbl_admin")
 	_, err := db.Exec(`CREATE TABLE tbl_admin (
 		id INT(11) UNSIGNED NOT NULL AUTO_INCREMENT,
 		username VARCHAR(255) NOT NULL,
@@ -76,12 +79,14 @@ func v1(db *DB) error {
 	if err != nil {
 		return err
 	}
+	slog.Debug("[DB] Adding unique key to table: tbl_admin")
 	_, err = db.Exec(`ALTER TABLE tbl_admin ADD UNIQUE KEY (username)`)
 	if err != nil {
 		return err
 	}
 
 	// table: tbl_cron
+	slog.Debug("[DB] Creating table: tbl_cron")
 	_, err = db.Exec(`CREATE TABLE tbl_cron (
 		id INT(8) UNSIGNED NOT NULL AUTO_INCREMENT,
 		title VARCHAR(255) NOT NULL DEFAULT '',
@@ -98,6 +103,7 @@ func v1(db *DB) error {
 	if err != nil {
 		return err
 	}
+	slog.Debug("[DB] Adding default cron jobs to table: tbl_cron")
 	_, err = db.Exec(`INSERT INTO tbl_cron (title, slug, description, run_every)
 		VALUES ('Delete old probe logs', 'delete_old_probe_logs', 'Delete old probe log from the database',120);`)
 	if err != nil {
@@ -105,6 +111,7 @@ func v1(db *DB) error {
 	}
 
 	// table: tbl_node
+	slog.Debug("[DB] Creating table: tbl_node")
 	_, err = db.Exec(`CREATE TABLE tbl_node (
 		id INT(11) UNSIGNED NOT NULL AUTO_INCREMENT,
 		protocol VARCHAR(6) NOT NULL DEFAULT 'http' COMMENT 'http | https',
@@ -139,6 +146,7 @@ func v1(db *DB) error {
 	}
 
 	// table: tbl_prober
+	slog.Debug("[DB] Creating table: tbl_prober")
 	_, err = db.Exec(`CREATE TABLE tbl_prober (
 		id INT(9) UNSIGNED NOT NULL AUTO_INCREMENT,
 		name VARCHAR(255) NOT NULL,
@@ -149,12 +157,15 @@ func v1(db *DB) error {
 	if err != nil {
 		return err
 	}
+
+	slog.Debug("[DB] Adding unique key to table: tbl_prober")
 	_, err = db.Exec(`ALTER TABLE tbl_prober ADD UNIQUE KEY (api_key)`)
 	if err != nil {
 		return err
 	}
 
 	// table: tbl_probe_log
+	slog.Debug("[DB] Creating table: tbl_probe_log")
 	_, err = db.Exec(`CREATE TABLE tbl_probe_log (
 		id BIGINT(20) UNSIGNED NOT NULL AUTO_INCREMENT,
 		node_id INT(11) UNSIGNED NOT NULL DEFAULT 0,
@@ -173,6 +184,7 @@ func v1(db *DB) error {
 	if err != nil {
 		return err
 	}
+	slog.Debug("[DB] Adding key to table: tbl_probe_log")
 	_, err = db.Exec(`ALTER TABLE tbl_probe_log ADD KEY (node_id)`)
 	if err != nil {
 		return err
diff --git a/internal/repo/cron.go b/internal/repo/cron.go
index 91f2d84..94ceee7 100644
--- a/internal/repo/cron.go
+++ b/internal/repo/cron.go
@@ -2,6 +2,7 @@ package repo
 
 import (
 	"fmt"
+	"log/slog"
 	"math"
 	"slices"
 	"strings"
@@ -40,10 +41,10 @@ func NewCron(db *database.DB) CronRepository {
 func (repo *CronRepo) RunCronProcess() {
 	for {
 		time.Sleep(60 * time.Second)
-		fmt.Println("Running cron...")
+		slog.Info("[CRON] Running cron cycle...")
 		list, err := repo.queueList()
 		if err != nil {
-			fmt.Println("Error parsing to struct:", err)
+			slog.Warn(fmt.Sprintf("[CRON] Error parsing queue list to struct: %s", err))
 			continue
 		}
 		for _, task := range list {
@@ -51,7 +52,7 @@ func (repo *CronRepo) RunCronProcess() {
 			currentTs := startTime.Unix()
 			delayedTask := currentTs - task.NextRun
 			if task.CronState == 1 && delayedTask <= int64(rerunTimeout) {
-				fmt.Println("SKIP STATE 1:", task.Slug)
+				slog.Debug(fmt.Sprintf("[CRON] Skipping task %s because it is already running", task.Slug))
 				continue
 			}
 
@@ -60,12 +61,12 @@ func (repo *CronRepo) RunCronProcess() {
 			repo.execCron(task.Slug)
 
 			runTime := math.Ceil(time.Since(startTime).Seconds()*1000) / 1000
-			fmt.Println("Runtime:", runTime)
+			slog.Info(fmt.Sprintf("[CRON] Task %s done in %f seconds", task.Slug, runTime))
 			nextRun := currentTs + int64(task.RunEvery)
 
 			repo.postRunTask(task.Id, nextRun, runTime)
 		}
-		fmt.Println("Cron done!")
+		slog.Info("[CRON] Cron cycle done!")
 	}
 }
 
@@ -151,7 +152,7 @@ func (repo *CronRepo) preRunTask(id int, lastRunTs int64) {
 	query := `UPDATE tbl_cron SET cron_state = ?, last_run = ? WHERE id = ?`
 	row, err := repo.db.Query(query, 1, lastRunTs, id)
 	if err != nil {
-		fmt.Println("ERROR PRERUN:", err)
+		slog.Error(fmt.Sprintf("[CRON] Failed to update pre cron state: %s", err))
 	}
 	defer row.Close()
 }
@@ -160,7 +161,7 @@ func (repo *CronRepo) postRunTask(id int, nextRun int64, runtime float64) {
 	query := `UPDATE tbl_cron SET cron_state = ?, next_run = ?, run_time = ? WHERE id = ?`
 	row, err := repo.db.Query(query, 0, nextRun, runtime, id)
 	if err != nil {
-		fmt.Println("ERROR PRERUN:", err)
+		slog.Error(fmt.Sprintf("[CRON] Failed to update post cron state: %s", err))
 	}
 	defer row.Close()
 }
@@ -168,7 +169,7 @@ func (repo *CronRepo) postRunTask(id int, nextRun int64, runtime float64) {
 func (repo *CronRepo) execCron(slug string) {
 	switch slug {
 	case "delete_old_probe_logs":
-		fmt.Println("Running task", slug)
+		slog.Info(fmt.Sprintf("[CRON] Start running task: %s", slug))
 		repo.deleteOldProbeLogs()
 		break
 	}
@@ -180,6 +181,6 @@ func (repo *CronRepo) deleteOldProbeLogs() {
 	query := `DELETE FROM tbl_probe_log WHERE date_checked < ?`
 	_, err := repo.db.Exec(query, startTs)
 	if err != nil {
-		fmt.Println(err)
+		slog.Error(fmt.Sprintf("[CRON] Failed to delete old probe logs: %s", err))
 	}
 }