diff --git a/.gitignore b/.gitignore
index 40402a5..a7bf151 100644
--- a/.gitignore
+++ b/.gitignore
@@ -132,3 +132,4 @@ dmypy.json
 
 .vscode/**
 requirements_temp.txt
+data
\ No newline at end of file
diff --git a/kickstarter/data_extraction/__init__.py b/kickstarter/data_extraction/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/kickstarter/data_extraction/preprocess.py b/kickstarter/data_extraction/preprocess.py
new file mode 100644
index 0000000..e7b9151
--- /dev/null
+++ b/kickstarter/data_extraction/preprocess.py
@@ -0,0 +1,52 @@
+import json
+from typing import Dict, List
+
+from kickstarter.models import CategoryModel, CreatorModel, ProjectModel
+
+
+def process_json(
+    filename: str,
+    projects: Dict[int, ProjectModel],
+    categories: Dict[int, CategoryModel],
+    creators: Dict[int, CreatorModel],
+):
+    with open(
+        filename,
+        "r",
+        encoding="utf-8",
+    ) as file:
+        filetype = file.read(1)
+        file.seek(0)
+        if filetype == "[":
+            jsondata: List[dict] = json.load(file)
+            for proyects_dict_wrapper in jsondata:
+                projects_dict_list: List[Dict] = proyects_dict_wrapper["projects"]
+                for project_dict in projects_dict_list:
+                    process_new_project(project_dict, projects, categories, creators)
+        elif filetype == "{":
+            for line in file:
+                project_dict = json.loads(line)["data"]
+                process_new_project(project_dict, projects, categories, creators)
+        else:
+            raise Exception("Invalid file format")
+
+
+def process_new_project(
+    project_dict: Dict,
+    projects: Dict[int, ProjectModel],
+    categories: Dict[int, CategoryModel],
+    creators: Dict[int, CreatorModel],
+):
+    project = ProjectModel(**project_dict)
+    category = CategoryModel(**project_dict["category"])
+    creator = CreatorModel(**project_dict["creator"])
+
+    if (
+        project.id in projects
+        and projects[project.id].state_changed_at > project.state_changed_at
+    ):
+        return
+
+    projects[project.id] = project
+    categories[category.id] = category
+    creators[creator.id] = creator