Rails binding to 'ip':3000 is giving me connection timeout

Hi im following this tutorial

https://www.digitalocean.com/community/tutorials/how-to-deploy-a-rails-app-with-puma-and-nginx-on-ubuntu-14-04

except that im using Ubuntu 16 The problem is after i bundle install my app, and following the

RAILS_ENV=production rails server --binding=server_public_IP

and try to access it via web app, all i get is err_conn_timeout

my app is indeed running, and this is what it shows

=> Booting Puma
=> Rails 5.1.4 application starting in production 
=> Run `rails server -h` for more startup options
Puma starting in single mode...
* Version 3.10.0 (ruby 2.4.1-p111), codename: Russell's Teapot
* Min threads: 5, max threads: 5
* Environment: production
* Listening on tcp://my.ip:3000
Use Ctrl-C to stop

i only followed the instructions on the tutorial and im not yet installing nginx. Im also quite new on this stuff, i had to rebuild my droplet cause i thought i broke something on my first run as i really can’t see my app and now im quite loss

this was also my netstat

Proto Recv-Q Send-Q Local Address           Foreign Address         State       User       Inode       PID/Program name
tcp        0      0 127.0.0.1:27017         0.0.0.0:*               LISTEN      112        31543       -               
tcp        0      0 0.0.0.0:22              0.0.0.0:*               LISTEN      0          16055       -               
tcp        0      0 my.ip.:3000    0.0.0.0:*               LISTEN      1000       97890       14743/my.ip.1
tcp        0      0 my.ip.:22      some.ip:42964    ESTABLISHED 0          80263       -               
tcp        0    664 my.ip.:22      some.ip:44726    ESTABLISHED 0          98189       -               
tcp        0      0 my.ip.:22      some.ip:34704     SYN_RECV    0          0           -               
tcp6       0      0 :::22                   :::*                    LISTEN      0          16074       -```