Introduction of the portal
Länsförsäkringar (“LF Bank”) is one of the early adopters of Open Banking in Sweden. More importantly, LF Bank has approached Open Banking from an opportunity perspective rather than just regulatory (PSD2 compliance). LF Bank explicitly invites third parties to collaborate and create innovative new services using the Bank's APIs. Obviously, that underscores the need for an accessible Developer Portal.
The Developer Portal has a very appealing, inviting user interface -- really inviting the interested developer to engage. The UI is very crisp (perhaps tidy, even - a fresh breath among portals offering an overwhelming amount of information). So it offers manageable chunks of information at a time. This is important, as Open Banking technical details tend to become quite overwhelming if you are not yet familiar with them. LF does a great job here.
The Portal is very user-friendly, with ample (though concise) explanation of the Portal's purpose, what actions can be taken to what end, etc. A page like https://developer.bank.lansforsakringar.se/#/home/learnmore is a clear example: clearly stating the objective and then clearly summarizing the steps that need to be taken to gain access to and test a given API.
Technical challenges, like ensuring the use of proper credentials, certificates, etc., are clearly explained. More importantly, the Portal offers an integrated API test facility that allows the developer to explore the API directly from the Portal environment (using Sandbox feature). To facilitate developers that prefer Postman, the Portal also offers a complete Postman collection for testing.
Furthermore, the Documentation offered in the Portal provides a nice, concise summary of important PSD2-related terminology and concepts, that gives the developer a good understanding of the fundamental use cases and related design choices, including functional flow diagrams and the like.