[racket] How to reduce my Racket web server's memory usage?

[fyooo]

I just bought a DigitalOcean 5$/month VPS with only 512M memory.


I started 3 different Racket webserver on different port, and using Nginx as 
reverse proxy. But I found that each process uses 80M average. I know that it's 
not a big deal in a machine with 16G memory, but in my VPS I have to merge all 
the webserver code in one rkt file in order to reduce the memory usage.‍
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