Been using this for some time and honestly, along with Skuid, was the only way I could reasonably expect our company to willingly make the jump to Salesforce!

Pat -

DLRS is awesome!  I’ve evaluated and used a couple of rollup tools and decided to go with DLRS for a number of reasons over the others.  Most notably, the fact that it’s open source and can be customized (I’ve made several contributions to the project over the last couple of months - see jondavis9898 pull requests) as well as the community effort that goes in to continually improving it.

For Skuid, I’ve built a javascript framework that handles rollups client side to mirror the rollup functionality provided by Skuid.  It wasn’t an easy undertaking but works well for the specific needs of the project I’m working on.

It would be insane if Skuid could build in a client side rollup tool similar to the Formula Field feature that was introduced in Banzai!  Absolutely insanely awesome!

Barry put me onto DLRS and it was a great tip. The source code is weighty, but we’ve made it do what we want and it’s really powerful.

On a related note, for those writing more than just basic trigger code in APEX, highly recommend the Financial Force APEX Common Enterprise Library.  The mocking framework alone is worth using it let alone the development patterns that are more a kin to traditional enterprise development (Unit Of Work, Domain, etc.)

Apex Common - https://github.com/financialforcedev/fflib-apex-common.
Apex Mocks - https://github.com/financialforcedev/fflib-apex-mocks

We certainly have tossed around the idea of roll up formulas.  We’ve got plenty of work still to do with the current batch of formula functions (As Matt Sones can attest)  but these guys are on the list…