diff --git a/main.go b/main.go
index 0e43718..a59f5fa 100644
--- a/main.go
+++ b/main.go
@@ -2,6 +2,7 @@ package main
 
 import (
 	"fmt"
+	"log/slog"
 	"net/http"
 	"os"
 	"strings"
@@ -38,12 +39,7 @@ func measureLatency(url string) (time.Duration, error) {
 	return time.Since(start), nil
 }
 
-func main() {
-	maybePool := os.Getenv("POOL")
-	pool := DEFAULT_POOL
-	if maybePool != "" {
-		pool = strings.Split(maybePool, ",")
-	}
+func findBestUpstream(pool []string) (string, error) {
 
 	// Measure latency concurrently
 	results := make(chan latencyResult, len(pool))
@@ -65,13 +61,14 @@ func main() {
 	var best latencyResult
 	best.latency = time.Hour // Start with a very high latency
 
-	fmt.Println("Latency results:")
+	slog.Debug("Latency results:")
+	var err error
 	for result := range results {
 		if result.err != nil {
-			fmt.Printf("  %s: ERROR - %v\n", result.url, result.err)
+			slog.Debug("connection error", slog.String("url", result.url), slog.Any("error", result.err))
 			continue
 		}
-		fmt.Printf("  %s: %v\n", result.url, result.latency)
+		slog.Debug("latency measured", slog.String("url", result.url), slog.Duration("latency", result.latency))
 
 		if result.latency < best.latency {
 			best = result
@@ -79,8 +76,30 @@ func main() {
 	}
 
 	if best.err == nil && best.latency < time.Hour {
-		fmt.Printf("\nBest connection: %s (latency: %v)\n", best.url, best.latency)
+		slog.Debug("Best connection", slog.String("url", best.url), slog.Duration("latency", best.latency))
+		return best.url, nil
 	} else {
-		fmt.Println("\nNo valid connections found")
+		slog.Debug("No valid connections found")
+		return "", err
 	}
+
+}
+
+func main() {
+	maybePool := os.Getenv("POOL")
+	pool := DEFAULT_POOL
+	if maybePool != "" {
+		pool = strings.Split(maybePool, ",")
+	}
+
+	if os.Getenv("DEBUG") == "1" {
+		slog.SetLogLoggerLevel(slog.LevelDebug)
+	}
+
+	bestUpstream, err := findBestUpstream(pool)
+	if err != nil {
+		panic(err)
+	}
+
+	fmt.Println(bestUpstream)
 }