TL;DR - Over two separate contracts with VaynerMedia, I helped to plan both minor service upgrades (web pages and online video) and major projects (Chase's FINN service) for Chase's student banking initiatives
The briefing for FINN really consisted of a basic set of business needs and a loosely defined demographic - Chase wanted to onboard students and in the process they wanted very specific details about who they were dealing with.

Because of this, we saw a series of silo'd forms and "levels of engagement"
To study this onboarding properly we produced a series of documents to take a look at the overall process of onboarding over time, and examine why people would "fail out" of it
Moving on from here we began to discuss the kinds of features and functionality that made it pretty certain that this would be 100% mobile as a service
Then we spent a short period of time creating very basic but visually adventurous versions of a usable mobile demo in order to investigate how the service might "feel in your hand"
These small mobile demos were ni turn slotted into the onboarding flow in order to present how the service might still cover all of its needs
As can be seen below, this resulted on a complex application / sign-in flow which nonetheless was made up of individual, easy to edit, modular pages
After this work came the simple upgrading of a "student hub" page which was at the time carrying bespoke video content from an ongoing campaign. In order to lay out the pages amd make sure they were delivered properly via Chase's CMS we had to do a bit of presenting and researching in order for it to work "In most browsers" 
As can be seen below, chase's CMS were using a variety of page types each of which responded differently to narrower and broader page sizes:
Once we had clear communication, constructing the final pages was simple
Chase 2018-2019
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Chase 2018-2019

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