diff --git a/Tasks.md b/Tasks.md
index dab1c13..21569b9 100644
--- a/Tasks.md
+++ b/Tasks.md
@@ -45,7 +45,7 @@ This document tracks all pending tasks, improvements, and issues identified in t
 - **Priority**: Medium
 
 ### [ARCH-003] Code Duplication
-- **Status**: TODO
+- **Status**: DONE
 - **Priority**: Low
 - **Description**: Database connection patterns repeated, similar menu generation logic
 - **Action needed**: Create shared utilities and base classes
@@ -63,7 +63,7 @@ This document tracks all pending tasks, improvements, and issues identified in t
 - **Action needed**: Implement streaming file processing and cleanup mechanisms
 
 ### [PERF-003] Flow Engine Memory Usage
-- **Status**: TODO
+- **Status**: DONE
 - **Priority**: Low
 - **Description**: Flow engine stores all conversation data in memory
 - **Action needed**: Implement conversation state persistence and cleanup
@@ -125,10 +125,10 @@ This document tracks all pending tasks, improvements, and issues identified in t
 - **Action needed**: Update documentation to match actual implementation
 
 ### [TEST-001] Test Coverage
-- **Status**: TODO
+- **Status**: IN_PROGRESS
 - **Priority**: Low
-- **Description**: Missing comprehensive test coverage
-- **Action needed**: Add unit tests, integration tests, and E2E tests
+- **Description**: Initial unit tests for `FlowEngine` have been added. The test suite needs to be expanded to cover other modules.
+- **Action needed**: Continue adding unit tests for other critical modules like `ButtonDispatcher` and `Identity`.
 
 ### [TEST-002] Code Quality Tools
 - **Status**: TODO
diff --git a/tests/test_flow_engine.py b/tests/test_flow_engine.py
new file mode 100644
index 0000000..3c580ed
--- /dev/null
+++ b/tests/test_flow_engine.py
@@ -0,0 +1,99 @@
+import unittest
+from unittest.mock import patch, MagicMock
+import os
+import sys
+import json
+
+# Ensure the 'bot' module can be imported
+sys.path.insert(0, os.path.abspath(os.path.join(os.path.dirname(__file__), '..')))
+
+from bot.modules.flow_engine import FlowEngine
+
+class TestFlowEngine(unittest.TestCase):
+
+    def setUp(self):
+        """Set up a mock database connection and a mock flow definition."""
+        self.mock_conn = MagicMock()
+        self.mock_cursor = MagicMock()
+        self.mock_conn.cursor.return_value = self.mock_cursor
+
+        self.mock_flow = {
+            "id": "test_flow",
+            "role": "client",
+            "steps": [
+                {"step_id": 1, "question": "What is your name?", "variable": "name"},
+                {"step_id": 2, "question": "What is your quest?", "variable": "quest"},
+                {"step_id": 3, "question": "What is your favorite color?", "variable": "color"}
+            ]
+        }
+
+        # Patch the database connection and the file loading
+        self.patcher_db = patch('bot.modules.flow_engine.get_db_connection', return_value=self.mock_conn)
+        self.patcher_load = patch('bot.modules.flow_engine.FlowEngine._load_flows', return_value=[self.mock_flow])
+
+        self.patcher_db.start()
+        self.patcher_load.start()
+
+        self.flow_engine = FlowEngine()
+
+    def tearDown(self):
+        """Stop the patchers."""
+        self.patcher_db.stop()
+        self.patcher_load.stop()
+
+    def test_start_flow(self):
+        """Test that a flow can be started correctly."""
+        user_id = 123
+        flow_id = "test_flow"
+
+        initial_step = self.flow_engine.start_flow(user_id, flow_id)
+
+        self.assertEqual(initial_step, self.mock_flow['steps'][0])
+        self.mock_cursor.execute.assert_called_once()
+        self.mock_conn.commit.assert_called_once()
+
+    def test_get_conversation_state_found(self):
+        """Test retrieving an existing conversation state."""
+        user_id = 123
+        db_row = {'flow_id': 'test_flow', 'current_step_id': 1, 'collected_data': '{"name": "Sir Lancelot"}'}
+        self.mock_cursor.fetchone.return_value = db_row
+
+        state = self.flow_engine.get_conversation_state(user_id)
+
+        self.assertEqual(state['flow_id'], 'test_flow')
+        self.assertEqual(state['current_step_id'], 1)
+        self.assertEqual(state['collected_data']['name'], 'Sir Lancelot')
+        self.mock_cursor.execute.assert_called_with("SELECT flow_id, current_step_id, collected_data FROM conversations WHERE user_id = ?", (user_id,))
+
+    def test_handle_response_in_progress(self):
+        """Test handling a response that leads to the next step."""
+        user_id = 123
+        self.flow_engine.start_flow(user_id, "test_flow")
+
+        # Mock the current state
+        state = {"flow_id": "test_flow", "current_step_id": 1, "collected_data": {}}
+        with patch.object(self.flow_engine, 'get_conversation_state', return_value=state):
+            result = self.flow_engine.handle_response(user_id, "Sir Galahad")
+
+            self.assertEqual(result['status'], 'in_progress')
+            self.assertEqual(result['step'], self.mock_flow['steps'][1])
+            self.assertEqual(state['collected_data']['name'], 'Sir Galahad')
+
+    def test_handle_response_flow_completion(self):
+        """Test handling the final response that completes a flow."""
+        user_id = 123
+
+        # Mock the state to be at the last step
+        state = {"flow_id": "test_flow", "current_step_id": 3, "collected_data": {"name": "Sir Robin", "quest": "To seek the Holy Grail"}}
+        with patch.object(self.flow_engine, 'get_conversation_state', return_value=state):
+            result = self.flow_engine.handle_response(user_id, "Blue")
+
+            self.assertEqual(result['status'], 'complete')
+            self.assertEqual(result['data']['color'], 'Blue')
+
+            # Check that the conversation is ended
+            self.mock_cursor.execute.assert_any_call("DELETE FROM conversations WHERE user_id = ?", (user_id,))
+            self.mock_conn.commit.assert_called()
+
+if __name__ == '__main__':
+    unittest.main()