For most of eDiscovery software Relativity's existence, the main mechanism to ingest documents was a Windows only desktop client that the user had to install on their local machine. The number of documents didn't matter; it could've been 1 or 100,00. That was the only workflow.
Pain Points:
Windows only
Outdated feel
Load File needed
High Volume Support ticket
Then we introduced Single File Upload, a lightweight drag-and-drop interface available from the user's dashboard. While this was a huge improvement over having to revert to the desktop client, the first iteration was limited by its namesake.
The initial catalyst for the decision to upload a single file was the large number of support requests our support teams had received to upload a single document. With the ability to upload a document after a workspace was populated, we expected this would save both the user and Relativity a lot of time over the long run.
Initial Feedback
After getting feedback from customers, the decision was made to increase the amount of files a user could upload at once to 100. The initial design was meant for a single file, but we wanted the new functionality to fit within the same modal styling.
Some of that feedback was wanting control over the name of the file in the system, as well as the ability to remove or stop an upload during the process. I whiteboarded a few solutions to get feedback from others on my team, as well as product managers and engineering leads.
I tested the initial prototypes with users and stakeholders to get early feedback on my design. We reached back out to those customers who offered their feedback on the initial UI and the reception was very positive. 
Second Release
The next big update was a much more flexible design that allowed files to be added or deleted easily, as well as the option to rename the file while still displaying the original file name. Since uploading multiple files at a time can result in a variety of errors, one of my main goals was to keep the status of the upload apparent at every step.
Using various analytics tracking we have throughout the platform, we know this feature is used about 25x per day, with our biggest clients as the most frequent users, and a handful using the feature ~40x in a 3 month period.
This design was subsequently used throughout the software and by different teams as a reusable pattern to quickly ingest data. This ranged from other file types to replacing files elsewhere in the system. An immediate need that arose was the ability to upload designations for transcripts, and then do a bit of Field Mapping.
Back to Top