TL;DR For most scenarios yes.  #YMMV

Umbraco 8 was launched with much fanfair in Feburary 2019, and as with most software there were some initial teething troubles which were quickly fixed.  But with 6 months passing, we began to wonder was Umbraco 8 ready for use in production environments.

After much research and testing, including a practical Proof of Concept, we feel that without a doubt the core CMS is ready for use for most production scenarios.  However, there are some scenarios where you should be cautious before continuing, and some where Umbraco 8 is not production ready.

One area of concern for us, was whether Umbraco 8 was ready for production use in a Load Balanced scenario as there is still very few referenceable examples of companies going live with Umbraco 8 hosted in a Load Balanced configuration.  However, having reviewed the evidence of previous production examples, the problems that were identified and fixed in the Umbraco core we felt that a PoC was sensible. 

Our PoC was a simple site of a handful of page, with three language variants, with fairly simple templates that was load tested with LoadImpact simulating 50 users generating 2000 page views per hour on a load balanced, autoscaling Azure App Services container.  The result of the PoC demonstrated that the site performed well, and was resilient to failure, and horizontally scaled well.  However, we have identified an intermittent ModelsBuilder error which we have raised with Umbraco Support.

Umbraco 8 is not ready for production if you are dependent on certain packages. The absence of Umbraco Courier or Umbraco Deploy on Premise is a critical flaw that will prevent some clients, including those in the UK Public Sector and Financial Services, from adopting Umbraco 8 for production use. Last week it was confirmed to us by Umbraco HQ that Courier will not be upgraded to Umbraco 8, and that Deploy on Premise will be its successor but a release date has yet been confirmed. 

Other packages notable by their absence from the Umbraco 8 ecosystem include Tea Commerce and CMSImport both which have plans for an upgrade in the near future.  Also, Stacked Content is notably absent, and much missed by many Umbraco Devs, however there is currently no plan to upgrade it.

With this in mind, careful consideration needs to be given as to whether you start a new project on Umbraco 8 or play it safe with Umbraco 7 for a while longer.