Tempest, the framework Brent Roose is working on, allows you to attach a tag to a singleton definition, which means you can have multiple singletons of the same class, as long as their tags differ.
PHP
Logarithmic auto-scaling for Laravel Horizon
A thoughtful write-up on adding logarithmic auto-scaling to Laravel Horizon. It shows how log-based weighting keeps huge queue spikes from starving smaller realtime queues while still giving large backlogs enough workers. Read more