Payment Processor Logger (AWS Lambda + CloudWatch)

A lightweight serverless payment logging service built with AWS Lambda.
It simulates payment processing, generates a transaction ID, and writes an audit log entry to CloudWatch Logs.

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✅ What this project does

• Receives a payment request (simulated event input)
• Generates a unique transaction ID
• Logs the payment event for audit + traceability
• Returns a structured success response

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🧱 Architecture (High-Level)

Client/Test Event → AWS Lambda → CloudWatch Logs

This mirrors how fintech systems handle audit trails, debugging, and traceability.

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📸 Screenshots (Evidence)

1) Lambda Function Test Result (Success Response)

2) CloudWatch Log Group Created Automatically

3) CloudWatch Log Stream Showing Transaction Event

4) Lambda Execution Log Output (Audit Evidence)

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🐞 Debugging & Lessons Learned (Real-World Troubleshooting)

Issue 1: DynamoDB Validation Errors

During development I attempted to store transactions in DynamoDB, but faced repeated errors due to missing partition key values and table configuration mismatches.

✅ Fix/Alternative: I switched to CloudWatch Logs to capture payment audit logs reliably while keeping the system lightweight.

Issue 2: Faster Logging & Reduced Complexity

CloudWatch logging removed the need for:

• DynamoDB table setup
• region mismatch issues
• IAM permission complexity
• schema constraints

✅ Result: a working, clean audit trail system.

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💼 Why this matters for businesses

This approach supports:

• Audit logging
• Transaction traceability
• Operational monitoring
• Compliance-style logging (useful in fintech + regulated environments)

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🛠️ Tech Stack

• AWS Lambda (Python)
• Amazon CloudWatch Logs

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✅ Next Improvements (Planned)

• Add API Gateway endpoint (REST)
• Add structured JSON logging
• Add error handling + retries
• Add metrics/alerts for failed transactions