Mario Gomes focused on backend reliability and payment integration across the Saleor codebase. On saleor/saleor, he stabilized Celery worker dependencies and integrated SQS-backed task queuing, improving asynchronous task reliability and simplifying deployment through clearer dependency management using Python and Dockerfile. He removed direct pycurl dependencies in favor of celery[sqs] extras, updating packaging files for reproducible builds and maintainability. In saleor/apps, Mario resolved Stripe PaymentIntent metadata propagation issues, ensuring webhook processing stability and traceability of Stripe transactions. He added targeted tests to validate metadata handling, demonstrating depth in API integration, backend development, and robust testing practices throughout his contributions.