Database Connection Pooling and Management

Re-use a set of active database connections rather than creating a new one for every request, preventing 'too many connections' errors and reducing latency.

Establishing a TCP connection and performing an SSL handshake for every query is incredibly slow. A Connection Pool maintains a 'warm' set of connections. When a query is made, it borrows a connection and returns it when done. In Node.js, libraries like pg, mysql2, or ORMs (Sequelize/Prisma) manage this. Senior engineers must tune the max and idle pool settings based on the server's traffic and the DB's capacity.