I've been working on a Magento2 site for a while now. and the entire site is quick, responsive, and working well in production mode. We work with Redis, and all caching on.
But when I place an order, this process takes over 1minute in load time. I even had to set the apache time-outs higher to not trigger a 503 error.
Is this a familiar issue. We don't have extensions running. Running on stable 2.1 and only did several design and layout modifications. Also on the normal theme, it's slow.