Front-End
As much as we all love using CLIs and writing our own network requests, a front-end is at the very least a nice-to-have for an end user, and an accessible, beautiful and extensible one is just icing.
Back-End
Whether it's producing fault and attack resistant APIs or simply ensuring our application has every endpoint a user may ever need - back-end development ultimately powers every app, ever.
DevOps
Between deploying production applications to edges worldwide, to ensuring development/monitoring environments are secure and accessible to my team - DevOps drives the backbone of any development cycle.
Maintenance
Everything from Security to Testing to Code Quality - easily some of the least appreciated aspects of web development and longevity, but some of my all-time favorite.