How to debug startup times

The bootup times for my Ember app have been getting really slow as of late. How do I figure out what’s specifically causing the long load times and see if there’s something I can do to reduce the load times? The current output doesn’t really tell me a whole lot:

Build successful - 39847ms.

Slowest Trees                                 | Total               
----------------------------------------------+--------------------- 
Babel                                         | 10377ms              
Babel                                         | 5747ms              
Babel                                         | 2338ms              
Babel                                         | 2096ms              
Babel                                         | 2087ms              

Slowest Trees (cumulative)                    | Total (avg)         
----------------------------------------------+--------------------- 
Babel (41)                                    | 29469ms (718 ms)    
 (4)                                          | 2433ms (608 ms)     

I’m currently on ember-cli 2.7.3. I wouldn’t classify my app as huge, but it’s not small either. It has around 8-10 routes and maybe 40 or so components.

There’s a ton of stuff here. You’re likely going to be interested in broccoli-viz: https://github.com/ember-cli/ember-cli/blob/master/PERF_GUIDE.md