Rogue-Like Interface, heavily inspired by the layout of A.A.C (An Average Campaign on roblox), decided to rebuild their entire lobby interface:

FOR INTERFACE ONLY PACK IS ON MY STORE/PAGE, THIS PACK INCLUDES INTERFACE + MODULAR ARCHITECTURE!:

A full character creation workspace: Appearance, races, classes, presets, branching skill tree, boons, outfits, accessories, and a hair-ID picker
A party/campaign interactive system: create-party -> party settings -> party menu with rosters and modifiers
Shop window (Simple transaction window for in-game purchases)
112 buttons (NOT WIRED IN INTERFACE ONLY PACK) ranging from paletters, sliders, toggles, all ranged in different adaptive regions (Top Bottom Left Right Center)
3,260+GUI Instances, fully responsive and scale to adapt to all devices (phone/tablet/desktop)

INTERFACE + MODULAR ARCHITECTURE PACK:

Interface Index - for looking up and configuring different interface elements
Button Interaction - configuring different button actions and for wiring
Window Manager - one-window state machine with 13 window modules
Controls - self tuning for different regions in the user interface
API - for hooking up and integrating different events into your game system
Config/Typography + TextScaling - built-in text scaling system to configure text labels and sizes
One bootstrap script (CLIENT)
Full fast and easy integration and implementation document written as a module
Never touches game-logic, this modular architecture will never write into your game!

FEATURES ALONGISDE MODULAR ARCHITECTURE:
Adding a button takes seconds: Name a button, write one function with that same name inside button interaction and done!
A self-indexing system: Instead of writing down a ton of WaitForChild chains one module indexes the whole tree by "Parent.Element" for fast and easy access to whatever element you chose!
Fault-isolated warnings: each module runs on a pcall so even if one window breaks it won't take down the whole interface and the warning will warn you of which window it was!