Firstly, applying the divide and conquer strategy for the development of a website. We will be using a Model 2 Architecture for this. There are three tiers in Model 2 Architecture, namely, Database, Business/Application, and UI.
First, start with the DB because it is the core and heart of any App. Design tables and relations followed by reusable stored procedures and functions which are not supposed to have much business workflow but can act like microservices. Keep on reviewing and revising it for making the DB efficient. The DB can be hosted on a third party Host or Cloud.
Second, create RESTful wrappers in the choice of your language on top of the DB created above. The RESTful wrappers simply call the stored procs and functions in the DB and return JSON. These wrappers can be generated or modified with a generic template of a RESTful wrapper in the choice of your language. Ensure the common code like getting a connection to DB and other minor functions are grouped in a separate file/class. Deploy these RESTful wrappers on the same host as the DB. Don't forget to allow cross-domain access by declaring header Access-Control-Allow-Origin: * in the .htaccess file. For help see this link.
Create a highly customizable and responsive UI using a CMS like Wix.com. The advantage with this the site can be tailored or customized dynamically at a click of the mouse.
I recommend divide and conquer strategy development here too. Have a core UI to RESTful delegators and common UI handlers as a small homegrown framework suiting your requirements. Create a JavaScript/ jQuery based UI handlers for handling the UI validations and events on top of the core JS file for the UI created in Step 3! Wix allows one to add common code snippets at the global level and customized code at the page level too, so we don't have to worry about it.
Avoid reinventing the wheel and look on Google to see whether the functionality you are looking for is available or not on the Internet. For example, addthis.com, webpushr.com, etc; are some of the widgets.
Use Cloudflare on top of the RESTful tier and with a firewall rule of allowing only the UI domain as a referrer so that it cannot be hacked.
Test the PageSpeed, SEO, and optimize accordingly. Keep building Website authority.
This strategy takes days for implementation rather than months. Please contact me at vasanth@fallov.com if you have any questions.