Custom Wordpress plugin development (simple job)

The plugin generates a button via shortcode with the following features 1. A button "Join Meditation NOW" is displayed 2. Below the button 2 statistics are displayed 1 - Meditators Today XX 2 - Meditators Alltime XX (XX is the number of meditators) 3. When clicking the button the page section is refreshed via ajax and some html code is displaied in place of the button 4. When clicking the button a new "Meditator" is registered in the statistics (the statistics are now showed on top of whatever content is displayed in place of the button) 5. Each button will have an ID and be connected to different statistics 6. In one page/post there can be more than 1 buttons We do not need an admin panel or any particular feature in backend, just the possibility to add a shortcode in frontend posts and pages You will be given full access to a test website and FTP access =========================== Other notes: 1. "Meditators Today XX" statistics are being automatically reset every 24 hours at UCT 0.00 2. "Meditators Today XX" statistics are being updated automatically every minute even if the user stays on the page, not refreshing it (can this cause too much load on the server?) 3. If the page is refreshed or closed/opened after clicking the button, the user will still see the html content while the button will be visible again (and the content hidden) only after 12 hours from the first click (via cookie or similar method) 4. The button shortcode has an "ID" value connected to its statistics, meaning that buttons with the same ID will update and show the same statistics, even if they are placed in different pages. 5. Shortcode example: [MEDBUTTON ID="XX"] some html code here: iframe, div, etc. [/MEDBUTTON] 6. All the labels/words should be translatable via backend using a plugin such as "Loco Translate" or "WPML" 7. Both the button and the statistics should have css classes so that they can easily be styled: Statistics html code example: <div class="medbutton-stats"><div class="medbutton-stats-now"><i class="fa fa-users"> Meditators Today XX</div> <div class="medbutton-stats-alltime"><i class="fa fa-users"> Meditators Alltime XX</div></div> 8. Everything must work normally even when a cache plugin is active (we use "WP-Optmize" cache plugin)