In einem Rutsch
verbatim: in one slide
This means: in one go, i.e. you perform what ever you have to do, without doing something else while you perform your work. So the focus is on "without any interruption". You perform your job like it was one inseparable task.
The phrase in einem Rutsch says nothing about how you structure your work within this monolithic task. It just says: The job is one single inseparable task.
If you have to do more than one task, then you still can use in einem Rutsch, but it's not the best choice.
Where it comes from:
I din't find any source, so this is what I think where it comes from. Maybe someone has a better explanation.
Imagine a pile of coal, and you add more and more pieces of coal on top of that pile. Suddenly on the side of the pile a larger amount of coal starts sliding down together. This movement of many pieces together is called "ein Rutsch" in German. I think, that this is where this phrase comes from.
German synonyms (sometimes with subtile differences in the meaning) are:
- auf einen Schlag - at one stoke
used for short tasks or events that happen together
- in einem Aufwasch - in one washing up
- in einem Schritt - in one step
- in einem Zug - in one move
(in this context: Zug = move in a game like chess)
- in einem Arbeitsgang - in one operation
- in einem Durchlauf - in one pass
- auf einmal - at once
- ohne Unterbrechung - without interrupt
"In einem Rutsch" can be interpreted as concurrent, but concurrency is not my first association when I hear "in einem Rutsch". If you explicitly want to express concurrency, than say one of these:
- zur selben Zeit
My first association with "in einem Rutsch" is consecutively. But as said above, it also can be interpreted as concurrent. If you want to be clear about consecutively say:
- Schlag auf Schlag
- der Reihe nach