diff --git a/backend/src/routes/pipelineRoutes.js b/backend/src/routes/pipelineRoutes.js
index 29a962f..002d69c 100644
--- a/backend/src/routes/pipelineRoutes.js
+++ b/backend/src/routes/pipelineRoutes.js
@@ -143,7 +143,9 @@ router.post(
     logger.info('post:audiobook:upload', {
       reqId: req.reqId,
       originalName: req.file.originalname,
-      sizeBytes: Number(req.file.size || 0)
+      sizeBytes: Number(req.file.size || 0),
+      mimeType: String(req.file.mimetype || '').trim() || null,
+      tempPath: String(req.file.path || '').trim() || null
     });
     const result = await pipelineService.uploadAudiobookFile(req.file, {
       format: req.body?.format,
diff --git a/backend/src/services/pipelineService.js b/backend/src/services/pipelineService.js
index e919e19..37c93f0 100644
--- a/backend/src/services/pipelineService.js
+++ b/backend/src/services/pipelineService.js
@@ -10804,6 +10804,14 @@ class PipelineService extends EventEmitter {
     try {
       await historyService.resetProcessLog(job.id);
       await historyService.appendLog(job.id, 'SYSTEM', `AAX-Upload empfangen: ${originalName}`);
+      logger.info('audiobook:upload:received', {
+        jobId: job.id,
+        originalName,
+        tempFilePath,
+        rawBaseDir,
+        outputFormat,
+        startImmediately
+      });
 
       const probeConfig = audiobookService.buildProbeCommand(ffprobeCommand, tempFilePath);
       const captured = await this.runCapturedCommand(probeConfig.cmd, probeConfig.args);
@@ -10822,12 +10830,25 @@ class PipelineService extends EventEmitter {
         rawTemplate,
         originalName
       );
+      logger.info('audiobook:upload:staging', {
+        jobId: job.id,
+        tempFilePath,
+        rawDir: storagePaths.rawDir,
+        rawFilePath: storagePaths.rawFilePath,
+        rawTemplate,
+        outputTemplate
+      });
 
       ensureDir(storagePaths.rawDir);
-      fs.renameSync(tempFilePath, storagePaths.rawFilePath);
+      moveFileWithFallback(tempFilePath, storagePaths.rawFilePath);
       stagedRawDir = storagePaths.rawDir;
       stagedRawFilePath = storagePaths.rawFilePath;
       chownRecursive(storagePaths.rawDir, settings?.raw_dir_owner);
+      logger.info('audiobook:upload:staged', {
+        jobId: job.id,
+        stagedRawDir,
+        stagedRawFilePath
+      });
 
       const makemkvInfo = this.withAnalyzeContextMediaProfile({
         status: 'SUCCESS',
@@ -10899,6 +10920,14 @@ class PipelineService extends EventEmitter {
         ...(startResult && typeof startResult === 'object' ? startResult : {})
       };
     } catch (error) {
+      logger.error('audiobook:upload:failed', {
+        jobId: job.id,
+        originalName,
+        tempFilePath,
+        stagedRawDir,
+        stagedRawFilePath,
+        error: errorToMeta(error)
+      });
       const updatePayload = {
         status: 'ERROR',
         last_state: 'ERROR',
diff --git a/install-dev.sh b/install-dev.sh
index ea16492..b7f84ce 100644
--- a/install-dev.sh
+++ b/install-dev.sh
@@ -119,6 +119,64 @@ info "Frontend-Host:         $FRONTEND_HOST"
 
 command_exists() { command -v "$1" &>/dev/null; }
 
+nginx_replace_or_insert_directive() {
+  local file="$1"
+  local directive_regex="$2"
+  local desired_line="$3"
+  local anchor_regex="$4"
+  local directive_sed_regex="${directive_regex//\//\\/}"
+  local anchor_sed_regex="${anchor_regex//\//\\/}"
+  local desired_sed_line="${desired_line//\//\\/}"
+
+  if grep -Eq "$directive_regex" "$file"; then
+    sed -i -E "0,/$directive_sed_regex/s//${desired_sed_line}/" "$file"
+    return 0
+  fi
+
+  sed -i "/$anchor_sed_regex/a\\$desired_line" "$file"
+}
+
+patch_existing_ripster_nginx_site() {
+  local file="$1"
+  local backup_file="${file}.bak-$(date +%Y%m%d%H%M%S)"
+
+  [[ -f "$file" ]] || return 1
+
+  cp -a "$file" "$backup_file"
+  info "Bestehende nginx-Konfiguration erkannt - ergänze Upload-/Proxy-Settings"
+  info "Backup erstellt: $backup_file"
+
+  nginx_replace_or_insert_directive \
+    "$file" \
+    '^[[:space:]]*client_max_body_size[[:space:]]+[^;]+;' \
+    '    client_max_body_size 8G;' \
+    'server_name .*;'
+
+  nginx_replace_or_insert_directive \
+    "$file" \
+    '^[[:space:]]*proxy_connect_timeout[[:space:]]+[^;]+;' \
+    '        proxy_connect_timeout 60s;' \
+    'location /api/ {'
+
+  nginx_replace_or_insert_directive \
+    "$file" \
+    '^[[:space:]]*proxy_send_timeout[[:space:]]+[^;]+;' \
+    '        proxy_send_timeout 3600s;' \
+    'location /api/ {'
+
+  nginx_replace_or_insert_directive \
+    "$file" \
+    '^[[:space:]]*proxy_read_timeout[[:space:]]+[^;]+;' \
+    '        proxy_read_timeout 3600s;' \
+    'location /api/ {'
+
+  nginx_replace_or_insert_directive \
+    "$file" \
+    '^[[:space:]]*proxy_request_buffering[[:space:]]+[^;]+;' \
+    '        proxy_request_buffering off;' \
+    'location /api/ {'
+}
+
 install_node() {
   header "Node.js installieren"
   local required_major=20
@@ -844,7 +902,10 @@ ok "ripster-backend.service erstellt"
 if [[ "$SKIP_NGINX" == false ]]; then
   header "nginx konfigurieren"
 
-  cat > /etc/nginx/sites-available/ripster <<EOF
+  if [[ -f /etc/nginx/sites-available/ripster ]]; then
+    patch_existing_ripster_nginx_site /etc/nginx/sites-available/ripster
+  else
+    cat > /etc/nginx/sites-available/ripster <<EOF
 server {
     listen 80;
     server_name ${FRONTEND_HOST} _;
@@ -866,8 +927,10 @@ server {
         proxy_set_header Host \$host;
         proxy_set_header X-Real-IP \$remote_addr;
         proxy_set_header X-Forwarded-For \$proxy_add_x_forwarded_for;
-        proxy_read_timeout 300s;
-        proxy_connect_timeout 10s;
+        proxy_read_timeout 3600s;
+        proxy_send_timeout 3600s;
+        proxy_connect_timeout 60s;
+        proxy_request_buffering off;
     }
 
     # WebSocket → Backend
@@ -882,6 +945,7 @@ server {
     }
 }
 EOF
+  fi
 
   # Alte Default-Seite deaktivieren, Ripster aktivieren
   rm -f /etc/nginx/sites-enabled/default
diff --git a/install.sh b/install.sh
index f1ebd15..8ec04b0 100644
--- a/install.sh
+++ b/install.sh
@@ -124,6 +124,64 @@ download_file() {
   return 1
 }
 
+nginx_replace_or_insert_directive() {
+  local file="$1"
+  local directive_regex="$2"
+  local desired_line="$3"
+  local anchor_regex="$4"
+  local directive_sed_regex="${directive_regex//\//\\/}"
+  local anchor_sed_regex="${anchor_regex//\//\\/}"
+  local desired_sed_line="${desired_line//\//\\/}"
+
+  if grep -Eq "$directive_regex" "$file"; then
+    sed -i -E "0,/$directive_sed_regex/s//${desired_sed_line}/" "$file"
+    return 0
+  fi
+
+  sed -i "/$anchor_sed_regex/a\\$desired_line" "$file"
+}
+
+patch_existing_ripster_nginx_site() {
+  local file="$1"
+  local backup_file="${file}.bak-$(date +%Y%m%d%H%M%S)"
+
+  [[ -f "$file" ]] || return 1
+
+  cp -a "$file" "$backup_file"
+  info "Bestehende nginx-Konfiguration erkannt - ergänze Upload-/Proxy-Settings"
+  info "Backup erstellt: $backup_file"
+
+  nginx_replace_or_insert_directive \
+    "$file" \
+    '^[[:space:]]*client_max_body_size[[:space:]]+[^;]+;' \
+    '    client_max_body_size 8G;' \
+    'server_name .*;'
+
+  nginx_replace_or_insert_directive \
+    "$file" \
+    '^[[:space:]]*proxy_connect_timeout[[:space:]]+[^;]+;' \
+    '        proxy_connect_timeout 60s;' \
+    'location /api/ {'
+
+  nginx_replace_or_insert_directive \
+    "$file" \
+    '^[[:space:]]*proxy_send_timeout[[:space:]]+[^;]+;' \
+    '        proxy_send_timeout 3600s;' \
+    'location /api/ {'
+
+  nginx_replace_or_insert_directive \
+    "$file" \
+    '^[[:space:]]*proxy_read_timeout[[:space:]]+[^;]+;' \
+    '        proxy_read_timeout 3600s;' \
+    'location /api/ {'
+
+  nginx_replace_or_insert_directive \
+    "$file" \
+    '^[[:space:]]*proxy_request_buffering[[:space:]]+[^;]+;' \
+    '        proxy_request_buffering off;' \
+    'location /api/ {'
+}
+
 install_node() {
   header "Node.js installieren"
   local required_major=20
@@ -647,7 +705,10 @@ ok "ripster-backend.service erstellt"
 if [[ "$SKIP_NGINX" == false ]]; then
   header "nginx konfigurieren"
 
-  cat > /etc/nginx/sites-available/ripster <<EOF
+  if [[ -f /etc/nginx/sites-available/ripster ]]; then
+    patch_existing_ripster_nginx_site /etc/nginx/sites-available/ripster
+  else
+    cat > /etc/nginx/sites-available/ripster <<EOF
 server {
     listen 80;
     server_name ${FRONTEND_HOST} _;
@@ -666,8 +727,10 @@ server {
         proxy_set_header Host \$host;
         proxy_set_header X-Real-IP \$remote_addr;
         proxy_set_header X-Forwarded-For \$proxy_add_x_forwarded_for;
-        proxy_read_timeout 300s;
-        proxy_connect_timeout 10s;
+        proxy_read_timeout 3600s;
+        proxy_send_timeout 3600s;
+        proxy_connect_timeout 60s;
+        proxy_request_buffering off;
     }
 
     location /ws {
@@ -681,6 +744,7 @@ server {
     }
 }
 EOF
+  fi
 
   rm -f /etc/nginx/sites-enabled/default
   ln -sf /etc/nginx/sites-available/ripster /etc/nginx/sites-enabled/ripster