Workflow of automated Multi Tenant SaaS Platform

We run a workflow-automation SaaS that lets customers build event-driven processes, route approvals, and call external services. The stack is Java 17, Spring Boot, PostgreSQL, Celery, Redis, Docker and AWS, all delivered in a fully multi-tenant environment.

The immediate goal is to harden security and drive horizontal scalability without slowing feature delivery. That means:

• Strengthening authentication, authorization and tenant-isolation layers
• Stress-testing and tuning PostgreSQL schemas, indexes and queries for millions of tenant rows
• Refining REST/JSON APIs so third-party services can plug in cleanly, with versioning and clear contracts
• Profiling Spring Boot services, Celery workers and Redis caching to remove bottlenecks, then containerising improvements for smooth AWS deploys
• Contributing design proposals and code reviews so architectural choices stay maintainable

Deliverables will include the updated code (clean, tested, documented), migration scripts if schemas change, API docs (OpenAPI preferred), a short decision log for any architectural changes, and a reproducible Docker build. A change is accepted when automated tests pass, load tests show equal or better performance, and the new container images deploy on our staging cluster without regression.

You will have access to the existing Git repo, CI pipeline and Terraform-based AWS staging account the moment we start.