Etienne contributed to the supabase/dbdev and supabase/pg_graphql repositories, focusing on security and database reliability. In dbdev, Etienne implemented Content Security Policy and X-Frame-Options headers using JavaScript and Next.js, reducing XSS and clickjacking risks by restricting resource origins and embedding. The CSP was dynamically configured to support preview environments, reflecting a nuanced approach to web security. Additionally, Etienne improved code maintainability by enforcing Prettier formatting standards. In pg_graphql, Etienne resolved a schema versioning bug by updating SQL logic to use explicit pg_catalog references, ensuring reliable schema increments and compatibility with evolving Cargo dependencies across deployment environments.