Symfony and Asset Management
Concatenation and sprites will have less of an impact than before, but they will still have some impact. The biggest issue with downloading multiple files instead of a single file with HTTP/1 isn't actually an HTTP-side problem, per se: there is some bandwidth-based overhead in requesting each file individually, but it's dwarfed by the time-based overhead of tearing down the TCP/IP session when you're done with one file, then starting up a new one for the next, and repeating this for every file you want to download.
Symfony3 and Assetic
Just this week the relevancy of Assetic in Symfony3 was questioned on Twitter:
An overwhelming number of respondents felt Assetic is no longer relevant in Symfony3. This quickly lead to a pull request for removing Assetic from the Symfony Standard Edition. There is plenty of good discussion about for and against the removal of Assetic. I recommend everyone interested in the matter to read the comments.
I am all for removing Assetic. Not that it's bad, but it continues to be alien to me and others. So while Assetic remains to be useful in applications built using it, I think we should let go and push it into maintenance for Symfony2/Symfony3 applications.
In fact many have already done so, but in a number of different ways, for example Gulp! Refreshment for Your Frontend Assets. Adopting alternative tools in Symfony3 requires clear documentation and a standard directory structure (Resources/private in Bundles?) to place the front end assets' source material.
Should Symfony3 adopt Puli?