Optimize & Fix Node.js + MongoDB APIs (TypeScript) Specialist needed

We need a specialist to optimize and fix existing Node.js APIs built with TypeScript and MongoDB. The work includes identifying performance bottlenecks, improving API reliability, and resolving issues that affect stability and response times. You should be comfortable reviewing current code, diagnosing problems, and implementing fixes that improve overall system performance. This is a small, short-term project for someone who can work independently and deliver clear improvements quickly.