Web-based user interface to quickly add values to text fields and select values in drop-down lists

Implement a fast user interface based on a text area where the user will introduce text to a) select values from drop-down lists and b) enter values in text fields. Emphasis must be placed on speed. i.e., the user interface must be fast, and feel as immediate and speedy as possible. 1) Frontend This is how it will work from the frontend point of view: 1-1) At the top of the page, there will be a text area. Below it, a list of drop-down lists and text fields. 1-2) When the user starts typing in the text area, he'll receive autosuggestions coming from the first text field or drop-down list below it. It must be possible to select any of these suggestions by using the up and down arrows and clicking enter. Again, put the emphasis on speed. If possible, there should not be database calls or AJAX requests at this point. 1-3) When the user types a delimiter character, let's make it the ";" character for now, the system will consider that the user has moved to the second drop-down list, thus providing autosuggestion coming from it. 1-4) For text fields, there will not be autosuggestions. The user will type in a value. However, being able to define rules for the information introduced in the text fields from the backend would be useful. For example, 1-4-1) Number greater than X and lower than Y. 1-4-2) Date 1-5) If the user selects a new value for a drop-down list by directly clicking on it, then the value must be changed in the text area too. Same goes for text fields. 2) Backend 2-1) Linked drop-down lists We'll define the available text fields and drop-down lists through a backend user interface. The backend should also allow us to specify dependencies between the drop-down lists and the text fields. For example, a particular drop-down list should only appear when the user selects a given value on a previous drop-down list, or has introduced a specific value on a preceding text field. This requirement probably makes necessary the use of a database, to set the relationships between tables that assure the integrity of the data. 2-2) Besides a name, each value in the drop-down lists will have an associated ID that identifies it. This ID will be alphanumeric. 2-3) At the bottom of the page, there will be a text area where the code of all the values selected in the dropdown lists will appear. For example, if the ID of the value selected in the first dropdown list is "100.1" and the value introduced in a text field that goes behind it is 200, then this area will display the following: 100.1 200 Please specify how long it'll take you to complete this project. What technologies are you going to use in this project? What Javascript framework, programming language, database, etc. How would you achieve the required goal of making the system as fast as possible?