Strongly agree -- I&#x27;m on a team at Facebook that has D code in production. There is a lot of investment that we&#x27;d have to do to make it what I&#x27;d call solidly production quality.<p>At one point, I found myself writing a heap profiler, since the tools available where inadequate. If your company doesn&#x27;t have the ability or will to fix issues deep within the runtime of the shiny new system you&#x27;re using, I&#x27;d be cautious about using a shiny new tool in production. I&#x27;m not necessarily saying &quot;Don&#x27;t do it&quot;, but you do need to think long and hard about how you&#x27;d handle a tricky bug in your tool.