Frontend GUI Implementation in Vaadin and Spring

Vaadin experience required. Vaadin experience required. Vaadin experience required. Need to create a front-end GUI "browser" application that will a. Authenticate users against Active Directory b. Fetch their roles from Active Directory c. Provide them application privileges [read/edit/approve/admin] fetched from Active Directory d. Read structure of a database table from the database dictionary e. Provide user the capability to search on list of tables e. Provide user the capability to search and read the records from any table in a tabular, paginated format f. Provide user the capability to edit these records on the frontend GUI or download an excel template for the same g. Provide user the capability to upload a filled-up excel template or save the edits on the front-end GUI h. Provide user the capability to submit the edits for approval i. Provide user the capability to approve/reject the edits j. Create a csv output file with the approved edits k. Handover output file to a back-end framework that processes the payload The back-end framework is NOT part of this project. The front-end would deal with a total of 5 tables for this project, the structure of which may be changed. Note that this app will NOT insert/update/delete to the database. It will only read from the database, fetch table structure and be able to show that structure and search the data on that structure dynamically, agnostic of the changes to the structure itself. It will also perform users and roles management. This will be a web app. GUI specifications are provided below. A. Fixed Header Row - DB column names B. Ability to reposition columns C. Ability to freeze columns D. Ability to write query 1. Just the where clause - return only business column if column not mentioned; order is natural keys first, then business keys 2. The entire query - either select * or select specific columns a. If columns are mentioned, display in the order they were mentioned E. Ability to resize columns F. Display Density - 3 depths G. Ability to use optional pagination - 10, 20, 50, 100, 500, Infinite Scroll H. Ability to sort on a column I. Inline Editing J. Ability to highlight multiple rows K. Expandable Rows [dropdown on natural keys to show audit columns] (or QuickView or Modal) L. Filtering on a column based on its datatype >, >=, =, <, <=, !=, like, not like, regex [Date should display a calendar and time and an optional start and end] M. Search on a column N. Add notes on a row O. Ability to hide columns or pick certain columns only P. Ability to provide x and y axis to see chart [visual table summary] Q. Hover Actions - Mark for deletion, Ignore, Generate Event Z. Exception Handling 1. GUI should always display non-technical error messages for any/all exceptions Visual Elements a. Progress Bar for all actions Looking for an experienced Spring and Vaadin front end developer for the above. Note that you must have Vaadin experience and we will want to see your past Vaadin work samples/demos/examples.