diff --git a/logger/context.go b/logger/context.go
index 99d2cf3..17a8bee 100644
--- a/logger/context.go
+++ b/logger/context.go
@@ -3,13 +3,12 @@ package logger
 import (
 	"context"
 	"log/slog"
-	"math/rand/v2"
 	"os"
 )
 
 type loggerKey struct{}
 
-// FromContext returns the logger from the context. If no logger is found, a new
+// FromContext returns the logger from the context. If no logger is found, the new logger is created with default logger's attributes.
 func FromContext(ctx context.Context) *slog.Logger {
 	if ctx == nil {
 		return logger.With()
@@ -42,34 +41,34 @@ func WithGroupContext(ctx context.Context, group string) context.Context {
 }
 
 // DebugContext logs at [LevelDebug] from logger in the given context.
-func DebugContext(ctx context.Context, msg string, args ...any) {
-	log(ctx, FromContext(ctx), slog.LevelDebug, msg, args...)
+func DebugContext(ctx context.Context, msg string, args ...slog.Attr) {
+	logAttrs(ctx, FromContext(ctx), slog.LevelDebug, msg, args...)
 }
 
 // InfoContext logs at [LevelInfo] from logger in the given context.
-func InfoContext(ctx context.Context, msg string, args ...any) {
-	log(ctx, FromContext(ctx), slog.LevelInfo, msg, args...)
+func InfoContext(ctx context.Context, msg string, args ...slog.Attr) {
+	logAttrs(ctx, FromContext(ctx), slog.LevelInfo, msg, args...)
 }
 
 // WarnContext logs at [LevelWarn] from logger in the given context.
-func WarnContext(ctx context.Context, msg string, args ...any) {
-	log(ctx, FromContext(ctx), slog.LevelWarn, msg, args...)
+func WarnContext(ctx context.Context, msg string, args ...slog.Attr) {
+	logAttrs(ctx, FromContext(ctx), slog.LevelWarn, msg, args...)
 }
 
 // ErrorContext logs at [LevelError] from logger in the given context.
-func ErrorContext(ctx context.Context, msg string, args ...any) {
-	log(ctx, FromContext(ctx), slog.LevelError, msg, args...)
+func ErrorContext(ctx context.Context, msg string, args ...slog.Attr) {
+	logAttrs(ctx, FromContext(ctx), slog.LevelError, msg, args...)
 }
 
 // PanicContext logs at [LevelPanic] and then panics from logger in the given context.
-func PanicContext(ctx context.Context, msg string, args ...any) {
-	log(ctx, FromContext(ctx), LevelPanic, msg, args...)
+func PanicContext(ctx context.Context, msg string, args ...slog.Attr) {
+	logAttrs(ctx, FromContext(ctx), LevelPanic, msg, args...)
 	panic(msg)
 }
 
 // FatalContext logs at [LevelFatal] and then [os.Exit](1) from logger in the given context.
-func FatalContext(ctx context.Context, msg string, args ...any) {
-	log(ctx, FromContext(ctx), LevelFatal, msg, args...)
+func FatalContext(ctx context.Context, msg string, args ...slog.Attr) {
+	logAttrs(ctx, FromContext(ctx), LevelFatal, msg, args...)
 	os.Exit(1)
 }
 
@@ -77,36 +76,3 @@ func FatalContext(ctx context.Context, msg string, args ...any) {
 func LogContext(ctx context.Context, level slog.Level, msg string, args ...any) {
 	log(ctx, FromContext(ctx), level, msg, args...)
 }
-
-// SamplingInfoContext logs at [LevelInfo] with sampling rate from logger in the given context.
-func SamplingInfoContext(ctx context.Context, rate float64, msg string, args ...any) {
-	if shouldLog(rate) {
-		InfoContext(ctx, msg, args...)
-	}
-}
-
-// SamplingWarnContext logs at [LevelWarn] with sampling rate from logger in the given context.
-func SamplingWarnContext(ctx context.Context, rate float64, msg string, args ...any) {
-	if shouldLog(rate) {
-		WarnContext(ctx, msg, args...)
-	}
-}
-
-// SamplingErrorContext logs at [LevelError] with sampling rate from logger in the given context.
-func SamplingErrorContext(ctx context.Context, rate float64, msg string, args ...any) {
-	if shouldLog(rate) {
-		ErrorContext(ctx, msg, args...)
-	}
-}
-
-// SamplingLogContext logs at the given level with sampling rate from logger in the given context.
-func SamplingLogContext(ctx context.Context, level slog.Level, rate float64, msg string, args ...any) {
-	if shouldLog(rate) {
-		LogContext(ctx, level, msg, args...)
-	}
-}
-
-// nolint: gosec
-func shouldLog(probability float64) bool {
-	return rand.Float64() < probability
-}
diff --git a/logger/duration.go b/logger/duration.go
index af28f7b..99c0675 100644
--- a/logger/duration.go
+++ b/logger/duration.go
@@ -1,6 +1,8 @@
 package logger
 
 import (
+	"context"
+	"fmt"
 	"log/slog"
 )
 
@@ -13,3 +15,24 @@ func durationToMsAttrReplacer(groups []string, attr slog.Attr) slog.Attr {
 	}
 	return attr
 }
+
+// middlewareDurationHuman is a middleware that adds a new string attribute for each duration attribute to render formatted duration
+func middlewareDurationHuman() middleware {
+	return func(next handleFunc) handleFunc {
+		return func(ctx context.Context, rec slog.Record) error {
+			rec.Attrs(func(attr slog.Attr) bool {
+				if attr.Value.Kind() == slog.KindDuration {
+					duration := attr.Value.Duration()
+					rec.AddAttrs(
+						slog.String(
+							fmt.Sprintf("%s_human", attr.Key),
+							duration.String(),
+						),
+					)
+				}
+				return true
+			})
+			return next(ctx, rec)
+		}
+	}
+}
diff --git a/logger/error.go b/logger/error.go
index 7d80259..5b6dcd2 100644
--- a/logger/error.go
+++ b/logger/error.go
@@ -6,8 +6,10 @@ import (
 
 	"github.com/Cleverse/go-utilities/logger/slogx"
 	"github.com/Cleverse/go-utilities/logger/stacktrace"
+	"github.com/lmittmann/tint"
 )
 
+// middlewareErrorStackTrace is a middleware that adds the error stack trace when ErrorKey or "err" is found.
 func middlewareErrorStackTrace() middleware {
 	return func(next handleFunc) handleFunc {
 		return func(ctx context.Context, rec slog.Record) error {
@@ -15,11 +17,15 @@ func middlewareErrorStackTrace() middleware {
 				if attr.Key == slogx.ErrorKey || attr.Key == "err" {
 					err := attr.Value.Any()
 					if err, ok := err.(error); ok && err != nil {
-						// rec.AddAttrs(slog.String(slogx.ErrorVerboseKey, fmt.Sprintf("%+v", err)))
-						rec.AddAttrs(slog.Any(slogx.ErrorStackTraceKey, stacktrace.ExtractErrorStackTraces(err)))
+						rec.AddAttrs(
+							slogx.Stringer(
+								slogx.ErrorStackTraceKey,
+								stacktrace.ExtractErrorStackTraces(err),
+							),
+						)
 					}
 				}
-				return false
+				return true
 			})
 			return next(ctx, rec)
 		}
@@ -31,10 +37,9 @@ func errorAttrReplacer(groups []string, attr slog.Attr) slog.Attr {
 		switch attr.Key {
 		case slogx.ErrorKey, "err":
 			if err, ok := attr.Value.Any().(error); ok {
-				if err != nil {
-					return slog.Attr{Key: slogx.ErrorKey, Value: slog.StringValue(err.Error())}
-				}
-				return slog.Attr{Key: slogx.ErrorKey, Value: slog.StringValue("null")}
+				aErr := tint.Attr(9, slogx.String(slogx.ErrorKey, err.Error()))
+				aErr.Key = slogx.ErrorKey
+				return aErr
 			}
 		case slogx.ErrorStackTraceKey:
 			type stackDetails struct {
diff --git a/logger/logger.go b/logger/logger.go
index 6bcea18..50de474 100644
--- a/logger/logger.go
+++ b/logger/logger.go
@@ -53,7 +53,13 @@ func SetLevel(level slog.Level) (old slog.Level) {
 	return old
 }
 
-// GetLogger returns the top-level logger
+// SetLogger sets the global logger to the provided logger instance.
+// This is useful for testing purposes where a mock logger is needed.
+func SetLogger(l *slog.Logger) {
+	logger = l
+	slog.SetDefault(logger)
+}
+
 func GetLogger() *slog.Logger {
 	return logger
 }
@@ -77,34 +83,34 @@ func WithGroup(group string) *slog.Logger {
 }
 
 // Debug logs at [LevelDebug].
-func Debug(msg string, args ...any) {
-	log(context.Background(), logger, slog.LevelDebug, msg, args...)
+func Debug(msg string, args ...slog.Attr) {
+	logAttrs(context.Background(), logger, slog.LevelDebug, msg, args...)
 }
 
 // Info logs at [LevelInfo].
-func Info(msg string, args ...any) {
-	log(context.Background(), logger, slog.LevelInfo, msg, args...)
+func Info(msg string, args ...slog.Attr) {
+	logAttrs(context.Background(), logger, slog.LevelInfo, msg, args...)
 }
 
 // Warn logs at [LevelWarn].
-func Warn(msg string, args ...any) {
-	log(context.Background(), logger, slog.LevelWarn, msg, args...)
+func Warn(msg string, args ...slog.Attr) {
+	logAttrs(context.Background(), logger, slog.LevelWarn, msg, args...)
 }
 
 // Error logs at [LevelError] with an error.
-func Error(msg string, args ...any) {
-	log(context.Background(), logger, slog.LevelError, msg, args...)
+func Error(msg string, args ...slog.Attr) {
+	logAttrs(context.Background(), logger, slog.LevelError, msg, args...)
 }
 
 // Panic logs at [LevelPanic] and then panics.
-func Panic(msg string, args ...any) {
-	log(context.Background(), logger, LevelPanic, msg, args...)
+func Panic(msg string, args ...slog.Attr) {
+	logAttrs(context.Background(), logger, LevelPanic, msg, args...)
 	panic(msg)
 }
 
 // Fatal logs at [LevelFatal] followed by a call to [os.Exit](1).
-func Fatal(msg string, args ...any) {
-	log(context.Background(), logger, LevelFatal, msg, args...)
+func Fatal(msg string, args ...slog.Attr) {
+	logAttrs(context.Background(), logger, LevelFatal, msg, args...)
 	os.Exit(1)
 }
 
@@ -160,15 +166,28 @@ func Init(cfg Config) error {
 	if cfg.Debug {
 		lvl.Set(slog.LevelDebug)
 		options.AddSource = true
+	}
+
+	// enable error stack traces if debug mode is set, or output is not text
+	if cfg.Debug || cfg.Output != "text" {
 		middlewares = append(middlewares, middlewareErrorStackTrace())
 	}
 
 	switch strings.ToLower(cfg.Output) {
 	case "json":
-		lvl.Set(slog.LevelInfo)
+		options.ReplaceAttr = attrReplacerChain(options.ReplaceAttr, durationToMsAttrReplacer)
 		handler = slog.NewJSONHandler(os.Stdout, options)
+
+		middlewares = append(middlewares,
+			middlewareDurationHuman(),
+		)
 	case "gcp":
+		options.ReplaceAttr = attrReplacerChain(options.ReplaceAttr, durationToMsAttrReplacer)
 		handler = NewGCPHandler(options)
+
+		middlewares = append(middlewares,
+			middlewareDurationHuman(),
+		)
 	default:
 		handler = tint.NewHandler(os.Stdout,
 			&tint.Options{
diff --git a/logger/logger_gcp.go b/logger/logger_gcp.go
index 437b3dd..18f7921 100644
--- a/logger/logger_gcp.go
+++ b/logger/logger_gcp.go
@@ -18,7 +18,6 @@ func NewGCPHandler(opts *slog.HandlerOptions) slog.Handler {
 		Level:     opts.Level,
 		ReplaceAttr: attrReplacerChain(
 			GCPAttrReplacer,
-			durationToMsAttrReplacer,
 			opts.ReplaceAttr,
 		),
 	})
diff --git a/logger/slogx/attr.go b/logger/slogx/attr.go
index fae1ae7..e644cbd 100644
--- a/logger/slogx/attr.go
+++ b/logger/slogx/attr.go
@@ -54,6 +54,9 @@ func String(key, value string) slog.Attr {
 
 // Stringer returns an slog.Attr for a fmt.Stringer value.
 func Stringer(key string, value fmt.Stringer) slog.Attr {
+	if value == nil {
+		return slog.Attr{}
+	}
 	return slog.String(key, value.String())
 }