Finance and tax teams need integrated workflows, automation, and security at scale to perform at their best. Our challenge was clear: transform a proven Java monolith into a modern SaaS platform without losing the expertise built over two decades. This was an opportunity to build something meaningful while maintaining what made our product trusted by customers worldwide. That required thoughtful engineering and a strategy that balances innovation with reliability.
Our core architectural approach: Tenant pools and security-first design
One of the most impactful decisions in our architecture was introducing tenant pools as our core architectural concept. Working closely with our partner AWS, we evaluated what would work best with customer security as the primary focus. This led us to design AWS accounts that host up to 100 tenants each - think of tenant pools as neighborhoods in a city, each containing multiple homes with shared infrastructure but independent security. This model combines scalability, security, and operational efficiency, ensuring predictable growth without unnecessary complexity.
Why not one account for all tenants? Risk management shaped this choice, as security is embedded in everything we do. A single AWS account for all tenants would create a massive blast radius - one failure could impact everyone. Tenant pools reduce this risk by limiting the impact to up to 100 tenants per pool. The strategic thinking behind our architectural decisions addresses real operational challenges, avoiding “noisy neighbors”, implementing advanced attribute-based access controls for strict security are a few of those discussed.
Our in-house Control Plane enables dynamic resource allocation, ensuring we balance security isolation with operational efficiency while keeping costs fair for all customers.
Looking back
Two years into this journey, the team is confident in the decisions made. They recognize they made the right call. This architecture reflects our culture: we solve complex, real-world challenges that shape the future of SaaS. From designing secure multi-tenant environments to leveraging AWS for deep integration, our teams are empowered to innovate and make decisions that matter.
If you’re passionate about cloud architecture, security, and building platforms that redefine industry standards, Lucanet is the place for you. Become part of a team that turns ambition into purpose.
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