App modernization leveraging cloud serverless services, DX and CI/CD practices
Multi-tenant serverless platform replacing legacy infrastructure with zero downtime — 25,000 users, 200,000 invoices, 90% cost reduction.
Cloud infrastructure and web
AWS, Azure, React
Client Challenge
A fast-growing LATAM startup needed to replace its legacy infrastructure with a platform that could operate cost-effectively at scale. The business required automated, scalable processes to integrate with a wide range of national tax services — think Turbo Tax, but for their market.
The existing system couldn't support the growth the company was experiencing. Every new customer added operational overhead, onboarding was slow, and infrastructure costs were growing proportionally with usage. The team needed a multi-tenant solution that would allow quick deployment of core infrastructure on customer accounts and dramatically faster onboarding — without rebuilding everything from scratch each time.
Solution Delivered
Renaiss designed and built a cloud-native, serverless platform on AWS that replaced the legacy infrastructure with zero downtime. The architecture was multi-tenant from the ground up, enabling rapid deployment of core infrastructure on new customer accounts and dramatically faster onboarding.
Core functional components included user and admin authentication, payment gateway subscriptions, tax calculation and federal reporting, invoice issuance against federal systems, analytics, and automated alerts.
Full tech stack: AWS Lambda, DynamoDB, API Gateway, Cognito, SQS, SNS, SES, and S3 — orchestrated with Terraform and deployed through GitLab Pipelines, with a React frontend. Every component was chosen deliberately: Lambda eliminated always-on servers, DynamoDB handled variable workloads without performance degradation, and the SQS-driven architecture decoupled services so failures in one component didn't cascade across the system.
Project Results
The platform now serves more than 25,000 registered users and has processed over 200,000 invoices — numbers the previous infrastructure could never have supported at the same cost.
The shift to serverless architecture delivered a 90% reduction in infrastructure costs. The company went from paying for fixed capacity regardless of usage to paying only for what it actually consumed. Beyond cost savings, the move to CI/CD practices fundamentally changed how the team shipped software — releases that previously carried significant risk became routine, and the development team could move faster and respond to user feedback more quickly.