diff --git a/src/deep_neurographs/geometry_utils.py b/src/deep_neurographs/geometry_utils.py
index 7bcb57b..ad929e7 100644
--- a/src/deep_neurographs/geometry_utils.py
+++ b/src/deep_neurographs/geometry_utils.py
@@ -9,7 +9,9 @@
 
 
 # Directional Vectors
-def get_directional(neurograph, i, proposal_tangent, window=5, n_svd_points=10):
+def get_directional(
+    neurograph, i, proposal_tangent, window=5, n_svd_points=10
+):
     directionals = []
     d = n_svd_points
     for branch in neurograph.get_branches(i):
@@ -18,7 +20,7 @@ def get_directional(neurograph, i, proposal_tangent, window=5, n_svd_points=10):
         elif branch.shape[0] <= d:
             xyz = deepcopy(branch)
         else:
-            xyz = deepcopy(branch[d : window + d, :])
+            xyz = deepcopy(branch[d: window + d, :])
         directionals.append(compute_tangent(xyz))
 
     # Determine best
@@ -94,7 +96,7 @@ def get_profile(img, xyz_arr, window=[5, 5, 5]):
 def fill_path(img, path, val=-1):
     for xyz in path:
         x, y, z = tuple(np.floor(xyz).astype(int))
-        img[x - 1 : x + 2, y - 1 : y + 2, z - 1 : z + 2] = val
+        img[x - 1: x + 2, y - 1: y + 2, z - 1: z + 2] = val
     return img
 
 
diff --git a/src/deep_neurographs/graph_utils.py b/src/deep_neurographs/graph_utils.py
index 79db58e..d82c084 100644
--- a/src/deep_neurographs/graph_utils.py
+++ b/src/deep_neurographs/graph_utils.py
@@ -21,16 +21,15 @@
 
 """
 
-from copy import deepcopy
 from random import sample
 
 import networkx as nx
 import numpy as np
 
-from deep_neurographs import geometry_utils, swc_utils, utils
+from deep_neurographs import geometry_utils, swc_utils
 
 
-def get_irreducibles(swc_dict, prune=True, depth=16, smooth=True):
+def get_irreducibles(swc_dict, swc_id=None, prune=True, depth=16, smooth=True):
     """
     Gets irreducible components of the graph stored in "swc_dict". The
     irreducible components consist of the leaf and junction nodes along with
@@ -40,6 +39,9 @@ def get_irreducibles(swc_dict, prune=True, depth=16, smooth=True):
     ----------
     swc_dict : dict
         Contents of an swc file.
+    swc_id : str, optional
+        Filename of swc which is used to run this routine with
+        multiprocessing. The default is None.
     prune : bool, optional
         Indication of whether to prune short branches. The default is True.
     depth : int, optional
@@ -85,7 +87,10 @@ def get_irreducibles(swc_dict, prune=True, depth=16, smooth=True):
             nbs = append_value(nbs, root, j)
             nbs = append_value(nbs, j, root)
             root = None
-    return {"leafs": leafs, "junctions": junctions, "edges": edges}
+
+    # Output
+    irreducibles = {"leafs": leafs, "junctions": junctions, "edges": edges}
+    return swc_id, irreducibles
 
 
 def get_irreducible_nodes(graph):
diff --git a/src/deep_neurographs/intake.py b/src/deep_neurographs/intake.py
index 997a18f..989c33e 100644
--- a/src/deep_neurographs/intake.py
+++ b/src/deep_neurographs/intake.py
@@ -8,9 +8,12 @@
 
 """
 
-import concurrent.futures
 import os
-from concurrent.futures import ThreadPoolExecutor, as_completed
+from concurrent.futures import (
+    ProcessPoolExecutor,
+    ThreadPoolExecutor,
+    as_completed,
+)
 from io import BytesIO
 from time import time
 from zipfile import ZipFile
@@ -65,7 +68,7 @@ def build_neurograph_from_local(
         prune=prune,
         prune_depth=prune_depth,
         smooth=smooth,
-        )
+    )
     print(f"build_neurograph(): {time() - t0} seconds")
 
     # Generate proposals
@@ -149,8 +152,7 @@ def build_neurograph_from_gcs_zips(
     )
     if search_radius > 0:
         neurograph.generate_proposals(
-            search_radius,
-            n_proposals_per_leaf=n_proposals_per_leaf,
+            search_radius, n_proposals_per_leaf=n_proposals_per_leaf
         )
     return neurograph
 
@@ -215,7 +217,6 @@ def download_zip(bucket, zip_path, min_size=0):
 
 
 def count_files_in_zips(bucket, zip_paths):
-    t0 = time()
     file_cnt = 0
     for zip_path in zip_paths:
         zip_blob = bucket.blob(zip_path)
@@ -244,7 +245,7 @@ def list_gcs_filenames(bucket, cloud_path, extension):
 
 
 # -- Build neurograph ---
-def build_neurograph(
+def build_neurograph_old(
     swc_dicts,
     bbox=None,
     img_path=None,
@@ -254,22 +255,53 @@ def build_neurograph(
 ):
     # Extract irreducibles
     t0 = time()
-    n_components = len(swc_dicts)
-    irreducibles = [None] * n_components
-    for i in range(n_components):
-        irreducibles[i] = gutils.get_irreducibles(
-            swc_dicts[i], prune=prune, depth=prune_depth, smooth=smooth
+    irreducibles = dict()
+    for key in swc_dicts.keys():
+        irreducibles[key] = gutils.get_irreducibles(
+            swc_dicts[key], prune=prune, depth=prune_depth, smooth=smooth
         )
     print(f"   --> get_irreducibles(): {time() - t0} seconds")
 
     # Build neurograph
     t0 = time()
-    neurograph = NeuroGraph(
-        bbox=bbox,
-        img_path=img_path,
-    )
-    for i in range(n_components):
-        neurograph.add_immutables(swc_dicts[i], irreducibles[i])
+    neurograph = NeuroGraph(bbox=bbox, img_path=img_path)
+    for key in swc_dicts.keys():
+        neurograph.add_immutables(swc_dicts[key], irreducibles[key])
+    print(f"   --> add_irreducibles(): {time() - t0} seconds")
+    return neurograph
+
+
+def build_neurograph(
+    swc_dicts,
+    bbox=None,
+    img_path=None,
+    prune=PRUNE,
+    prune_depth=PRUNE_DEPTH,
+    smooth=SMOOTH,
+):
+    # Extract irreducibles
+    irreducibles = dict()
+    with ProcessPoolExecutor() as executor:
+        # Assign Processes
+        processes = [None] * len(swc_dicts)
+        for i, key in enumerate(swc_dicts.keys()):
+            processes[i] = executor.submit(
+                gutils.get_irreducibles,
+                swc_dicts[key],
+                key,
+                prune,
+                prune_depth,
+                smooth,
+            )
+        for process in as_completed(processes):
+            process_id, result = process.result()
+            irreducibles[process_id] = result
+
+    # Build neurograph
+    t0 = time()
+    neurograph = NeuroGraph(bbox=bbox, img_path=img_path)
+    for key in swc_dicts.keys():
+        neurograph.add_immutables(irreducibles[key], swc_dicts[key], key)
     print(f"   --> add_irreducibles(): {time() - t0} seconds")
     return neurograph
 
@@ -283,8 +315,6 @@ def get_paths(swc_dir):
 
 
 def get_start_ids(swc_dicts):
-    # runtime: ~ 1 minute
-    t0 = time()
     node_ids = []
     cnt = 0
     for swc_dict in swc_dicts:
@@ -308,6 +338,6 @@ def report_runtimes(
     print(
         f"Runtime for Zips {files_processed}: {round(chunk_runtime, 4)} seconds"
     )
-    print(f"Zip Processing Rate: {file_rate} seconds")
+    print(f"Zip Processing Rate: {rate} seconds")
     print(f"Approximate Total Runtime: {round(eta, 4)} minutes")
     print("")
diff --git a/src/deep_neurographs/neurograph.py b/src/deep_neurographs/neurograph.py
index e648c6c..afbc893 100644
--- a/src/deep_neurographs/neurograph.py
+++ b/src/deep_neurographs/neurograph.py
@@ -9,7 +9,6 @@
 """
 
 from copy import deepcopy
-from time import time
 
 import networkx as nx
 import numpy as np
@@ -18,7 +17,7 @@
 
 from deep_neurographs import geometry_utils
 from deep_neurographs import graph_utils as gutils
-from deep_neurographs import swc_utils, utils
+from deep_neurographs import utils
 from deep_neurographs.densegraph import DenseGraph
 from deep_neurographs.geometry_utils import dist as get_dist
 
@@ -34,11 +33,7 @@ class NeuroGraph(nx.Graph):
     """
 
     def __init__(
-        self,
-        bbox=None,
-        swc_dir=None,
-        img_path=None,
-        label_mask=None,
+        self, bbox=None, swc_dir=None, img_path=None, label_mask=None
     ):
         super(NeuroGraph, self).__init__()
         # Initialize paths
@@ -85,7 +80,7 @@ def init_densegraph(self):
         self.densegraph = DenseGraph(self.swc_paths)
 
     # --- Add nodes or edges ---
-    def add_immutables(self, swc_dict, irreducibles):
+    def add_immutables(self, irreducibles, swc_dict, swc_id):
         # Add nodes
         node_id = dict()
         leafs = irreducibles["leafs"]
@@ -96,11 +91,10 @@ def add_immutables(self, swc_dict, irreducibles):
                 node_id[i],
                 xyz=np.array(swc_dict["xyz"][i]),
                 radius=swc_dict["radius"][i],
-                swc_id=swc_dict["swc_id"],
+                swc_id=swc_id,
             )
 
         # Add edges
-        t0 = time()
         edges = irreducibles["edges"]
         for i, j in edges.keys():
             # Get edge
@@ -111,11 +105,7 @@ def add_immutables(self, swc_dict, irreducibles):
             # Add edge
             self.immutable_edges.add(frozenset(edge))
             self.add_edge(
-                node_id[i],
-                node_id[j],
-                xyz=xyz,
-                radius=radii,
-                swc_id=swc_dict["swc_id"]
+                node_id[i], node_id[j], xyz=xyz, radius=radii, swc_id=swc_id
             )
             xyz_to_edge = dict((tuple(xyz), edge) for xyz in xyz)
             check_xyz = set(xyz_to_edge.keys())
@@ -133,7 +123,13 @@ def add_immutables(self, swc_dict, irreducibles):
             self.junctions.add(node_id[j])
 
     # --- Proposal Generation ---
-    def generate_proposals(self, search_radius, n_proposals_per_leaf=3, optimize=False, optimization_depth=10):
+    def generate_proposals(
+        self,
+        search_radius,
+        n_proposals_per_leaf=3,
+        optimize=False,
+        optimization_depth=10,
+    ):
         """
         Generates edges for the graph.
 
diff --git a/src/deep_neurographs/swc_utils.py b/src/deep_neurographs/swc_utils.py
index a97df60..a234808 100644
--- a/src/deep_neurographs/swc_utils.py
+++ b/src/deep_neurographs/swc_utils.py
@@ -9,10 +9,6 @@
 
 """
 
-import os
-from copy import deepcopy as cp
-from itertools import repeat
-
 import networkx as nx
 import numpy as np
 
@@ -23,11 +19,10 @@
 
 # -- io utils --
 def process_local_paths(paths, min_size, bbox=None):
-    swc_dicts = []
+    swc_dicts = dict()
     for path in paths:
-        swc_dict_i = parse_local_swc(path, bbox=bbox)
-        swc_dict_i["swc_id"] = utils.get_swc_id(path)
-        swc_dicts.append(swc_dict_i)
+        swc_id = utils.get_swc_id(path)
+        swc_dicts[swc_id] = parse_local_swc(path, bbox=bbox)
     return swc_dicts
 
 
diff --git a/src/deep_neurographs/utils.py b/src/deep_neurographs/utils.py
index 0cd9b0c..17b8602 100644
--- a/src/deep_neurographs/utils.py
+++ b/src/deep_neurographs/utils.py
@@ -255,21 +255,21 @@ def open_tensorstore(path, driver):
 def read_img_chunk(img, xyz, shape):
     start, end = get_start_end(xyz, shape)
     return img[
-        start[2] : end[2], start[1] : end[1], start[0] : end[0]
+        start[2]: end[2], start[1]: end[1], start[0]: end[0]
     ].transpose(2, 1, 0)
 
 
 def get_chunk(arr, xyz, shape):
     start, end = get_start_end(xyz, shape)
     return deepcopy(
-        arr[start[0] : end[0], start[1] : end[1], start[2] : end[2]]
+        arr[start[0]: end[0], start[1]: end[1], start[2]: end[2]]
     )
 
 
 def read_tensorstore(ts_arr, xyz, shape):
     start, end = get_start_end(xyz, shape)
     return (
-        ts_arr[start[0] : end[0], start[1] : end[1], start[2] : end[2]]
+        ts_arr[start[0]: end[0], start[1]: end[1], start[2]: end[2]]
         .read()
         .result()
     )