Full Stack / Web Developer needed for Online Data Portal Development

We are looking for a (team of) full stack web frontend & backend developer to develop a web portal for data file uploading, saving and basic visualization. Main tasks include: - Build overall server infrastructure - Build user management structure (three levels of users required: admin user, full user & limited user) 1) Admin user can add users to the team, purchase and assign subscriptions to other users, upload/download/analyze data file, view analyzed data of all users in the team 2) Full user can upload/download/analyze data file, view analyzed data shared from the file owner 3) Limited user can only view analyzed data shared from the file owner - Create online database for data management - Create a login page for user to register account and login - Create a user dashboard after login - Three functions are required on dashboard 1) Upload a data file (csv or wav, sample file will be provided) and save it as a record in database (I expect 10000 to 500000 data in each file) 2) View previously uploaded data and select a data record 3) Data visualization with plots for selected data record. Basic plotting features should be implemented (pan, zoom, cursor). Some basic signal processing/calculation will be required (we will provide instruction). The selected language/framework should be powerful enough to handle more advanced computation in the future. - Create subscription and payment structure for the admin user to purchase and distribute to other users in the team. Subscription options should include 30-day free trial, monthly subscription and yearly subscription. If you are interested, please create a proposal file to include: - Tools to be used (server, cloud, front-end language/framework, back-end language/framework, database, etc) - Briefly explain reason for each selected tool - Tools cost (e.g. server fee, cloud service fee, etc) - Total development cost and hours - Lead time - Some basic information about yourself 1) Link 3-5 of your best related work samples 2) How long have you been working in software development 3) Are you working individually or under a company 4) Do you have any coding related degree, if so list it 5) List your strong skills in Windows software development 6) Rate your English level from 0 to 10 7) Will you be available for weekly online audio/video meeting 8) Do you have development experience with other platforms