Build a SaaS booking & invoicing software

I need a UK, US or EU based software developer. I will be selecting a freelancer Monday 12th Sept. Please show me previous examples of your work and list what programming languages you will use. I will need the selected developer to sign an NDA and other documents for security purposes. I will send wireframe designs of the software to freelancers once I have been in contact with yourselves. Once the main bulk of the coding is done, I am have a highly successful software company director reviewing it, so please no time wasters! I need someone who can develop a SaaS software that business owners can purchase for a monthly or annual fee. I will need a backend to activate customers accounts, see their details, their payments & apply discounts. The business owners will purchase the software, set up their account and create accounts for their employees to see registers, bookings and their rotas. It needs to be an app on the App Store (if not to expensive) and a website. WHAT I NEED: • My customers can purchase this software and create an account which allows them to create other accounts for their employees and also control their access to what they see (i.e employee wages and payslips data). • This software will allow management to create customer profiles and take bookings on certain days, input / select hourly or day rates and add in discounts. The employees can then access their account via website or app and tick if the customer has arrived and at what time and also then select what time they left. The management will need to be able to input their email in the setting and then create profiles for their customers allowing the management to see what days/times they have booked in/attended the past few months with their names and email and then directly email over the invoice from the software. • The management account will need to have a page to allow them to input on a calendar which employees are working and what time they start and finish with two boxes only the management account are able to see and control - their hourly/day rate and overtime. This needs to allow the management to be able to print pay slips from the data collected on each employee. MY QUESTIONS: • Can you link the mine and my customers data to the cloud? How would you link the software up to the cloud? • Would linking the software to a cloud cost extra and how much? • What coding languages would you use? • How long do you believe it would take to get to testing stages of this software? • How will you ensure my software and my customers data is protected? I will need support of the selected developer going forward to help maintain / upgrade this software so please disclose what your hourly fee is too. Depending on your experience / skills, one other project is in the pipeline. I look forward to hearing from you all. If you have any previous examples please attach them. Kindest regards, Elliott