The author of this article switched from SQLite to PostgreSQL for a blog dashboard application after discovering that some queries were taking longer than expected. They found that while SQLite was easier to set up, it struggled with larger datasets and concurrent requests. In contrast, PostgreSQL performed better in these scenarios but required more configuration. After fine-tuning the memory settings for PostgreSQL, the author saw significant improvements in performance. The article emphasizes the importance of benchmarking and optimizing applications based on specific use cases and environments.