Custom CSV generating web app needed.

I have a CSV file that I have to manually edit and maintain that lists a number of network devices (routers) by unique serial number and then has 15 columns per group of network settings (each group of settings defines a VLAN).

To add a new group of network settings I have to add another 15 columns and make the headers unique (number sequentially). Then I can put the data in the columns.

When ready I then take the CSV and drag it into an online management platform to apply the settings to the target devices.

I want to automate it.
Three Stages:
1. MVP. A web interface that models 'unique devices' and 'vlan settings' then lets me build a new 'configuration' that combines any number of unique devices with any number of vlan settings. That configuration is then saved in a database and can at any time be used to generate a CSV in the right format that I can download.

2. Same as 1 but now for public users too. They can create an account, login and add their own devices, vlans and build their own configurations that they can then download as a CSV. This is a secure multi-user web app (and free).

3. Commercialisation of the web app for a set fee a month. And integration of the web app with the API of the device management app so configs can be applied remotely and don't need to be downloaded as CSVs.

I am only interested in stage 1 at this time.

Attached is a sample CSV. This has 4 sets of configurations (groups of columns) for three unique devices (rows).