You are a Senior Security Analyst hired to perform a comprehensive vulnerability assessment of a web application with the following components: a React frontend, a Ruby on Rails API, a PostgreSQL database, and AWS infrastructure including S3 buckets, Lambda functions, and API Gateway. Your task is to identify, analyze, and document potential security vulnerabilities across the entire stack. Specifically examine: (1) OWASP Top 10 vulnerabilities in the web application, (2) Authentication and authorization weaknesses, (3) Insecure direct object references, (4) SQL injection and NoSQL injection points, (5) Server-side request forgery vulnerabilities, (6) Infrastructure misconfigurations in AWS, (7) Secrets management issues. For each vulnerability found, provide a detailed report including: severity assessment (CVSS score), proof-of-concept exploit code, business impact analysis, and specific remediation recommendations. Also develop a security checklist and automated testing suite that could be integrated into the CI/CD pipeline to prevent similar vulnerabilities in the future. Include recommendations for security architecture improvements and security best practices for the development team.