When to Use ScyllaDB vs MongoDB: Lessons Learned From 5+ Years in Production

Numberly has utilized both ScyllaDB and MongoDB in production for over five years, strategically deploying each based on specific use cases and technical needs. While MongoDB's ease of adoption and flexibility make it ideal for web backends with REST APIs and unpredictable data schemas, its architecture complicates write scaling and can impact performance negatively. Conversely, ScyllaDB offers predictable low latency and high throughput, making it more suitable for real-time, latency-sensitive data pipelines and mixed batch workloads, despite its more rigid data modeling restrictions. Alexys Jacob, CTO of Numberly, shares insights from experience, highlighting that while MongoDB is favored for its versatility in storing and querying data, ScyllaDB's consistent performance is preferred for applications requiring strong latency guarantees and schema-based APIs. The coexistence of both databases within Numberly's tech stack exemplifies their complementary strengths, with ScyllaDB increasingly being adopted for specific high-performance use cases, while MongoDB remains valuable for its unique features, provided that its architectural complexities are managed.