Franken Theme - Reverse engineering contributed themes

Drupal has a large ecosystem of contributed and core themes. A lot of pieces can be reused and repurposed on custom themes. However, awareness about said themes and their quality of life improvements can at times be missed. It can be hard to recognize them unless you did it the hard way once. As learn from different projects, I will walk you through some scenarios and why those snippets, hooks, and modules, could come in handy. Let's brainstorm together and discover some new ones.

Learning Objectives

Understand the vast ecosystem of themes to play, contribute, and borrow ideas from. 
Examine how others use and work with Twig, SASS, SDC, CSS, hooks, bundlers, TailwindCSS, bootstrap, and more. 
Discover how others work around certain challenges and how that could save you time next time it crosses your TODO list.
If you have to upgrade or build a new theme hopefully this would save you time, frustration, and money.
Agenda

Base themes and their tradeoffs A quick brainstorming of theming challenges.
Challenges and some lessons learned about extending, creating, or modifying a theme.
Why contribute to other themes/initiatives? What to look for when reverse engineering a theme?
Why every theme should add a theme recipe?
A quick recap on how to do that.
Insights on experience builder and that may mean for community themes.
Let's explore theme 1.
Let's review my list of tips from this one and any other items you may have noticed.
Let's explore theme 2. 
Let's review my list of tips from this one and any other items you may have noticed.
Let's explore theme 3.
Let's review my list of tips from this one and any other items you may have noticed.

Projects we might explore include: OpenY, DrupalX, Drupal Commerce, Umami, DrupalGovCon2017, Drupal4Gov, fldrupal.camp, and maybe a few more.

Some of it will be guided and some hands-on.