The difficulty arose from the fact that the base setup needed to change, elements like fonts with all their variants required changing. Secondly, the color pallet for the project had to be switched, as well as small details of rounded corners, backgrounds, footer, etc.
The first big hurdle was establishing the base for UI. Atomic design approach helped me get started quickly; our collection of rules and elements grew with us as a team. Involving programmers at the beginning, let me build reusable components, proper headings, and paragraphs from day one. We chose a system that combined Angular components with enough flexibility to mix with the brand requirements.
Starting with essential elements like forms, inputs, text layers, and hierarchy, we built a shared understanding between design and implementation. Reusing and iterating on established ingredients let us keep consistency as well as the freedom to adjust when needed accordingly.
This fundamental work we put in at the beginning of our project saved us a lot of time later on. Halfway through the project (unfortunately slightly late at that point), we received a directive to adjust to the corporate identity guidelines. Thanks to our base setup, changing all the details of UI was a medium task easily fitted into the sprint and corrected quickly.