I international transited through SVO twice in the last 2 weeks, both times very quick and easy.
After deplaning, simply follow the Transit signs, show your connecting boarding pass (or get one from the service desk), and head to your next gate. Not more than a 5 minute delay, really.
One transit was from Terminal D to Terminal F, which is a bit of a long walk- 20 minutes at a good pace, and the terminals along the way are crowded. But no issues, just a long walk.
On a side note, the lounges at SVO are OK. Not great not terrible. Depending on timing, they can be empty and quiet. The SVO lounges in WAW were really nice and new, with good hot and cold foods and tempting desserts and pastries...