diff --git a/cmd/reddit-scraper/main.go b/cmd/reddit-scraper/main.go
index 57c221f..c4a70f2 100644
--- a/cmd/reddit-scraper/main.go
+++ b/cmd/reddit-scraper/main.go
@@ -2,34 +2,34 @@ package main
 
 import (
 	"context"
-	"flag"
 	"fmt"
 	"os"
 	"os/signal"
 	"syscall"
 	"time"
+
+	"github.com/yourname/reddit-scraper/internal/config"
+	"github.com/yourname/reddit-scraper/internal/logging"
 )
 
 func main() {
-	keyword := flag.String("keyword", "", "Search keyword (required)")
-	limit := flag.Int("limit", 100, "Max posts to fetch")
-	flag.Parse()
-
-	if *keyword == "" {
-		fmt.Fprintln(os.Stderr, "-keyword is required")
+	cfg, err := config.Load()
+	if err != nil {
+		fmt.Fprintln(os.Stderr, "config load:", err)
 		os.Exit(2)
 	}
 
+	logger := logging.Init(cfg.LogLevel)
+	logger.Info("starting", "keyword", cfg.Keyword, "limit", cfg.Limit, "concurrency", cfg.Concurrency)
+
 	ctx, cancel := signal.NotifyContext(context.Background(), syscall.SIGINT, syscall.SIGTERM)
 	defer cancel()
 
 	// placeholder: in future wire up controller
-	fmt.Printf("Starting crawl for keyword=%s limit=%d\n", *keyword, *limit)
-
 	select {
 	case <-time.After(1 * time.Second):
-		fmt.Println("Done (placeholder)")
+		logger.Info("done (placeholder)")
 	case <-ctx.Done():
-		fmt.Println("Cancelled")
+		logger.Info("cancelled")
 	}
 }
diff --git a/internal/config/config.go b/internal/config/config.go
index 6637577..499d813 100644
--- a/internal/config/config.go
+++ b/internal/config/config.go
@@ -62,6 +62,28 @@ func Load() (*Config, error) {
 		return nil, fmt.Errorf("creating output dir: %w", err)
 	}
 
+	// Basic validation
+	if cfg.Limit <= 0 {
+		return nil, fmt.Errorf("limit must be > 0")
+	}
+	if cfg.Concurrency <= 0 {
+		return nil, fmt.Errorf("concurrency must be > 0")
+	}
+	if cfg.RetryLimit < 0 {
+		return nil, fmt.Errorf("retry-limit must be >= 0")
+	}
+	if cfg.RateLimitDelay <= 0 {
+		return nil, fmt.Errorf("rate-limit delay must be > 0")
+	}
+
+	// Ensure dedup cache parent dir exists
+	dedupDir := filepath.Dir(cfg.DedupCachePath)
+	if dedupDir != "" && dedupDir != "." {
+		if err := os.MkdirAll(filepath.Clean(dedupDir), 0o755); err != nil {
+			return nil, fmt.Errorf("creating dedup cache dir: %w", err)
+		}
+	}
+
 	return cfg, nil
 }
 
diff --git a/internal/logging/logger.go b/internal/logging/logger.go
index 35a50b0..9284cc4 100644
--- a/internal/logging/logger.go
+++ b/internal/logging/logger.go
@@ -3,13 +3,30 @@ package logging
 import (
 	"log/slog"
 	"os"
+	"strings"
 )
 
+func parseLevel(s string) slog.Level {
+	s = strings.ToUpper(strings.TrimSpace(s))
+	switch s {
+	case "TRACE":
+		return slog.LevelDebug
+	case "DEBUG":
+		return slog.LevelDebug
+	case "INFO":
+		return slog.LevelInfo
+	case "WARN", "WARNING":
+		return slog.LevelWarn
+	case "ERROR":
+		return slog.LevelError
+	default:
+		return slog.LevelInfo
+	}
+}
+
 // Init initializes a global logger and returns it. Level is a string like "INFO" or "DEBUG".
 func Init(level string) *slog.Logger {
-	handler := slog.NewTextHandler(os.Stderr, &slog.HandlerOptions{AddSource: false})
-	logger := slog.New(handler)
-	// Note: slog's level filtering is configured per Handler via HandlerOptions in Go 1.25;
-	// here we rely on consumer code to not spam at debug when level is INFO.
-	return logger
+	lvl := parseLevel(level)
+	handler := slog.NewTextHandler(os.Stderr, &slog.HandlerOptions{AddSource: false, Level: lvl})
+	return slog.New(handler)
 }