The Hidden Cost of Login: How I Decoupled Session Cleanup from Authentication in NestJs

A developer optimized their NestJs login flow by moving session cleanup to a scheduled job, reducing database contention and improving user experience. This is achieved by decoupling session cleanup from authentication, keeping the critical path lean and focused on the user's login request. The fix involves using @nestjs/schedule to run the cleanup job periodically, rather than blocking the login response with a DELETE operation. This principle of separating critical path operations from housekeeping tasks can be applied to other areas of software development.