Restoring rent payments. Reducing AWS costs.

The existing application had incomplete property-management workflows. Tenant rent payments failed even when landlords had configured how to receive payments, and the Settings navigation did not work.

I rebuilt the frontend and backend and handled deployment as part of my work at Mashup Garage, and did about 95% of the work on the new application myself. It uses an AWS Amplify frontend, a Docker-based backend on Elastic Beanstalk, and DynamoDB for data storage.

I used AI-assisted development during the rebuild. While implementing the replacement application, I checked the old application’s behavior, identified incomplete workflows, and addressed them in the new implementation.

• Tenant rent payments: the fault was in the Stripe Checkout session that tenants used to pay rent. I updated the Stripe configuration and the webhook in the rebuilt backend.
• Settings navigation: replaced the broken navigation as part of the frontend rebuild.

The client’s monthly AWS bill went from $400+ to $150+, more than 62% lower. Two changes drove the reduction: removing unused infrastructure and changing the AWS support plan.