Online Exam System with smart statistics (Read entire project first)

Namaste! I am planning to create an online exam service with a subscription model. For example, My exam has 4 subjects, Each subject has 2~4 sections, Each of those sections contains a few questions in a group. Unlike traditional tests, Questions are grouped and often times answers are shared with other questions within the same group. Hirearchy: Exam -> Subject -> Section -> Question Set -> Part A/B/C (Parts are set of questions) Those parts are like articles we post on WP/Medium where inserting [answer-16] will be used as either a text box / drag-n-drop / choices / selection while taking the exam. User will write content like this and put space for an answer like [answer-19] this and so on... While placing [answer-19] it actually clicks on question type button and selects a respective option such as selection/choices/drag-n-drop/to fill the blank etc. With that option, the user will be offered to provide options/possible answers/variations and marks to display in the final output. Just like the answer short code, I need drag-n-drop option shortcode like [dd] to place options, that can be dragged, like this[/dd] Admin will create exams with a manual selection of qs where a bunch of question automatically will be added into an exam like a full exam will contain a total of 10 QS(question-sets) from 4 different subjects. The exam will contain long paragraphs as a reference as well it will contain pictures / audio / flow chart (admin will need some function to put simple flow charts / picture with option to point on specific part to let user select/write answer (f.e. there's a car picture and we put two fields one on windshield and another on tire and user will see space on both those places where they can write down or drag n drop answer) Everything user answers in the exam should be recorded (create DB to collect answers) and other information which I shall be able to display for a recommendation like what subject is strong/weak and so on. Now subscription model; User will have to buy a membership plan to access all exams. User can add his friends into his/her account with a few features limited like performance statistics and all which can be purchased as an addon. What you'll need to do? Try to understand this project and find out the best way to turn it into a real-life product. Suggest platform/technology/database and alternative options that is scalable, easy to manage, ideal for a product like mine. Your proposal should start with You should hire me because... (your expertise goes here). We can go for readymade subscription scripts if required to avoid additional development time/cost. Don't forget to open attachment and visit URL as well learn basic concept for the same. Thank you, Namaste!