Nginx Cache with Reverse Proxy

NginxCache.conf

user nginx;
worker_processes 1;
error_log /var/log/nginx/error.log warn;
pid /var/run/nginx.pid;

events {
    worker_connections 1024;
}

http {
    include /etc/nginx/mime.types;
    default_type application/octet-stream;
    log_format main '$remote_addr - $remote_user [$time_local] -- "$server_name$uri" -- "$request" '
                    '$status $body_bytes_sent "$http_referer" "$http_user_agent" "$http_x_forwarded_for"';
    access_log /var/log/nginx/access.log main;
    sendfile on;
    keepalive_timeout 65;

    server {
        listen 80 default_server;
        server_name www.domain.com;
        server_tokens off;

        return 301 https://$server_name$request_uri;
    }

    server {
        listen 443 ssl http2;
        server_name www.domain.com;
        expires 1y;    # Here is the cache expiration
        server_tokens off;
        add_header X-Frame-Options "SAMEORIGIN";

        ssl_certificate /etc/letsencrypt/live/www.domain.com/fullchain.pem;
        ssl_certificate_key /etc/letsencrypt/live/www.domain.com/privkey.pem;

        location / {
            proxy_read_timeout 90;
            proxy_connect_timeout 90;
            proxy_redirect off;

            proxy_set_header Host $host;
            proxy_set_header X-Real-IP $remote_addr;
            proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
            proxy_set_header X-Forwarded-Proto $scheme;

            proxy_pass http://frontend:9000;
        }

        location /api/v1 {
            proxy_read_timeout 90;
            proxy_connect_timeout 90;
            proxy_redirect off;

            proxy_set_header Host $host;
            proxy_set_header X-Real-IP $remote_addr;
            proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
            proxy_set_header X-Forwarded-Proto $scheme;

            proxy_pass http://backend;
        }

        # Here is the cache setup on static files
        location ~* /.(css|js|png|jpg|jpeg|gif|ico)$ {
            add_header Cache-Control "public";
        }
    }
}