diff --git a/graphgen/engine.py b/graphgen/engine.py
index 7b871a61..2f1abf61 100644
--- a/graphgen/engine.py
+++ b/graphgen/engine.py
@@ -7,15 +7,12 @@
 
 import ray
 import ray.data
-from dotenv import load_dotenv
 from ray.data import DataContext
 
 from graphgen.bases import Config, Node
 from graphgen.common import init_llm, init_storage
 from graphgen.utils import logger
 
-load_dotenv()
-
 
 class Engine:
     def __init__(
diff --git a/graphgen/models/evaluator/kg/structure_evaluator.py b/graphgen/models/evaluator/kg/structure_evaluator.py
index 997639be..58e5b812 100644
--- a/graphgen/models/evaluator/kg/structure_evaluator.py
+++ b/graphgen/models/evaluator/kg/structure_evaluator.py
@@ -97,8 +97,8 @@ def _calculate_powerlaw_r2(degree_map: Dict[str, int]) -> Optional[float]:
             log_frequencies = np.log(frequencies)
 
             # Linear regression on log-log scale
-            r_value, *_ = stats.linregress(log_degrees, log_frequencies)
-            r2 = r_value**2
+            result = stats.linregress(log_degrees, log_frequencies)
+            r2 = result.rvalue**2
 
             return float(r2)
         except Exception as e:
diff --git a/graphgen/run.py b/graphgen/run.py
index d3d47cd3..6b303ee1 100644
--- a/graphgen/run.py
+++ b/graphgen/run.py
@@ -6,6 +6,7 @@
 
 import ray
 import yaml
+from dotenv import load_dotenv
 from ray.data.block import Block
 from ray.data.datasource.filename_provider import FilenameProvider
 
@@ -13,6 +14,8 @@
 from graphgen.operators import operators
 from graphgen.utils import CURRENT_LOGGER_VAR, logger, set_logger
 
+load_dotenv()
+
 sys_path = os.path.abspath(os.path.dirname(__file__))
 
 
diff --git a/webui/app.py b/webui/app.py
index 98b02601..695e1b87 100644
--- a/webui/app.py
+++ b/webui/app.py
@@ -160,6 +160,7 @@ def run_graphgen(params: WebuiParams, progress=gr.Progress()):
             "op_name": "generate",
             "type": "map_batch",
             "dependencies": ["partition"],
+            "save_output": True,
             "execution_params": {"replicas": 1, "batch_size": 128},
             "params": {
                 "method": params.mode,
@@ -168,14 +169,17 @@ def run_graphgen(params: WebuiParams, progress=gr.Progress()):
         }
     )
 
-    config = {"global_params": {"working_dir": working_dir}, "nodes": nodes}
+    config = {
+        "global_params": {
+            "working_dir": working_dir,
+            "graph_backend": "kuzu",
+            "kv_backend": "rocksdb",
+        },
+        "nodes": nodes,
+    }
 
     try:
         # 4. Initialize and Run Engine
-        # Initialize Ray if not already running (Engine handles this mostly, but good for safety)
-        if not ray.is_initialized():
-            ray.init(ignore_reinit_error=True, log_to_driver=True)
-
         engine = Engine(config, operators)
 
         # Start with an empty dataset to kick off the pipeline