mediainstance.com
The singular suits a product rather than a platform. One service, one clear function, which is how infrastructure components are actually sold.
Instance is cloud vocabulary for a running, provisioned thing. Applied to media it reads as on-demand media compute: transcoding, streaming, rendering, packaging.
That’s a demanding technical category, since media workloads are heavier than almost anything else companies run, and the services handling them sell to engineers who care about throughput and cost per hour rather than branding. A name in their vocabulary lands correctly.
It suits a transcoding service, a streaming infrastructure product, a rendering backend, or a media API. There’s a plainer reading too, where an instance is an occurrence, suiting media monitoring or clipping services.
Two words, no hyphen, .com.
Offers welcome.