Audit engagements with Series A SaaS companies reveal a common theme: infrastructure designed for rapid MVP prototyping breaks when transaction volumes surge. Aligning engineering velocity with infrastructure scaling requires avoiding three common mistakes.
1. Shared Database Connection Pools
In early stages, microservices often communicate directly with a single database using a shared connection pool. Under heavy traffic, query spikes from one minor service can exhaust connection pools, crashing the entire database and affecting all other systems.
2. Flat IAM and VPC Layouts
To move quickly, startups frequently deploy services inside a single VPC and share a root IAM role. This flat design exposes the entire infrastructure to security risks if a single web application is compromised, and complicates compliance preparation audits.
3. Runaway Cloud Watch and Logging Costs
Configuring debug logging levels on all production microservices can lead to massive data transfer charges. Companies often spend thousands of dollars streaming repetitive log data to log aggregators without setting up indexing filters.