diff --git a/examples/bitcoin-tracker/AIRFLOW_INTEGRATION.md b/examples/bitcoin-tracker/AIRFLOW_INTEGRATION.md
index 082651f..a59702a 100644
--- a/examples/bitcoin-tracker/AIRFLOW_INTEGRATION.md
+++ b/examples/bitcoin-tracker/AIRFLOW_INTEGRATION.md
@@ -200,6 +200,10 @@ sys.path.insert(0, os.path.abspath(os.path.dirname(__file__) + "/../.."))
 
 from ingest_bitcoin_prices import fetch_bitcoin_price, insert_to_bigquery
 
+# Configuration from environment variables
+GCP_PROJECT_ID = os.environ["GCP_PROJECT_ID"]  # required: fail at parse time rather than
+# targeting a placeholder project that does not exist
+
 # Default arguments
 default_args = {
     "owner": "data-engineering",
@@ -256,7 +260,7 @@ with DAG(
         """Insert price data to BigQuery."""
         price_data = context["ti"].xcom_pull(task_ids="fetch_bitcoin_price")
         
-        project_id = os.environ.get("GCP_PROJECT_ID", "<<YOUR_PROJECT_HERE>>")
+        project_id = GCP_PROJECT_ID
         dataset = "crypto_data"
         table = "bitcoin_prices"
         
@@ -286,7 +290,7 @@ with DAG(
         task_id="check_data_quality",
         sql=f"""
         SELECT COUNT(*) > 0
-        FROM `{os.environ.get('GCP_PROJECT_ID', '<<YOUR_PROJECT_HERE>>')}.crypto_data.bitcoin_prices`
+        FROM `{GCP_PROJECT_ID}.crypto_data.bitcoin_prices`
         WHERE DATE(timestamp) = CURRENT_DATE()
         """,
         use_legacy_sql=False,
@@ -297,7 +301,7 @@ with DAG(
         task_id="verify_transformations",
         sql=f"""
         SELECT COUNT(*) > 0
-        FROM `{os.environ.get('GCP_PROJECT_ID', '<<YOUR_PROJECT_HERE>>')}.crypto_data.daily_price_summary`
+        FROM `{GCP_PROJECT_ID}.crypto_data.daily_price_summary`
         WHERE price_date >= DATE_SUB(CURRENT_DATE(), INTERVAL 1 DAY)
         """,
         use_legacy_sql=False,
diff --git a/examples/bitcoin-tracker/airflow-quickstart.sh b/examples/bitcoin-tracker/airflow-quickstart.sh
index 7ca6788..5eb079e 100755
--- a/examples/bitcoin-tracker/airflow-quickstart.sh
+++ b/examples/bitcoin-tracker/airflow-quickstart.sh
@@ -18,7 +18,12 @@ NC='\033[0m' # No Color
 # Configuration
 PROJECT_DIR=$(pwd)
 AIRFLOW_HOME=${AIRFLOW_HOME:-$HOME/airflow}
-GCP_PROJECT_ID=${GCP_PROJECT_ID:-<<YOUR_PROJECT_HERE>>}
+GCP_PROJECT_ID=${GCP_PROJECT_ID:-}
+if [ -z "$GCP_PROJECT_ID" ]; then
+    echo "❌ Error: GCP_PROJECT_ID environment variable not set"
+    echo "Usage: export GCP_PROJECT_ID=your-project-id && ./airflow-quickstart.sh"
+    exit 1
+fi
 
 echo -e "${BLUE}Configuration:${NC}"
 echo "  Project Directory: $PROJECT_DIR"
diff --git a/examples/bitcoin-tracker/load_bitcoin_price_batch.py b/examples/bitcoin-tracker/load_bitcoin_price_batch.py
index dd45a97..5a24be9 100644
--- a/examples/bitcoin-tracker/load_bitcoin_price_batch.py
+++ b/examples/bitcoin-tracker/load_bitcoin_price_batch.py
@@ -6,6 +6,7 @@
 from google.cloud import bigquery
 from datetime import datetime
 import os
+import sys
 import json
 import tempfile
 
@@ -67,7 +68,17 @@ def load_to_bigquery_batch(row, project_id, dataset_id="crypto_data", table_id="
         os.unlink(temp_file)
 
 if __name__ == "__main__":
-    project_id = os.getenv("GCP_PROJECT_ID", "<<YOUR_PROJECT_HERE>>")
+    # Get project ID from environment or command line
+    project_id = os.getenv("GCP_PROJECT_ID")
+
+    if not project_id and len(sys.argv) > 1:
+        project_id = sys.argv[1]
+
+    if not project_id:
+        print("❌ Error: GCP_PROJECT_ID environment variable not set")
+        print("Usage: python load_bitcoin_price_batch.py [PROJECT_ID]")
+        print("   or: export GCP_PROJECT_ID=your-project-id && python load_bitcoin_price_batch.py")
+        sys.exit(1)
     
     print(f"🚀 Fetching Bitcoin price...")
     price_data = fetch_bitcoin_price()
diff --git a/examples/bitcoin-tracker/runtime/ingest_bitcoin_prices.py b/examples/bitcoin-tracker/runtime/ingest_bitcoin_prices.py
index 8107182..8265138 100644
--- a/examples/bitcoin-tracker/runtime/ingest_bitcoin_prices.py
+++ b/examples/bitcoin-tracker/runtime/ingest_bitcoin_prices.py
@@ -12,6 +12,19 @@
 
 def main():
     """Fetch Bitcoin price from CoinGecko API and insert to BigQuery"""
+    # Resolve the target project before doing any work, so a missing
+    # GCP_PROJECT_ID fails here rather than silently targeting a placeholder.
+    project_id = os.getenv("GCP_PROJECT_ID")
+
+    if not project_id and len(sys.argv) > 1:
+        project_id = sys.argv[1]
+
+    if not project_id:
+        print("❌ Error: GCP_PROJECT_ID environment variable not set")
+        print("Usage: python ingest_bitcoin_prices.py [PROJECT_ID]")
+        print("   or: export GCP_PROJECT_ID=your-project-id && python ingest_bitcoin_prices.py")
+        sys.exit(1)
+
     print("🚀 Starting Bitcoin price ingestion...")
     
     # Fetch from CoinGecko API (free tier, no auth required)
@@ -47,7 +60,6 @@ def main():
     }
     
     # Insert to BigQuery
-    project_id = os.getenv("GCP_PROJECT_ID", "<<YOUR_PROJECT_HERE>>")
     dataset_id = "crypto_data"
     table_id = "bitcoin_prices"