The phrase "a stage through which" is correct and usable in written English.
It can be used to describe a process or phase that someone or something goes through in a sequence of events or development.
Example: "Adolescence is a stage through which every individual must navigate to reach adulthood."
Alternatives: "a phase in which" or "a step that involves".
Because of the visual nature of the product, Swift-Kanban allows you to visualize your workflow with post-it-like notes on a Kanban board, each representing a workflow stage through which your work can flow.
The actor Michael Gambon, who for some years has been struggling to remember scripts, admitted over the weekend he now wears an earpiece on stage through which a prompter can feed him lines.
Listening to records became a kind of mirror stage through which musicians confronted their "true" selves.
This is the preliminary stage through which everyone must pass, but a philosopher, and a divine philosopher (hakim muta'allih) at that, must go beyond this stage in pursuit of the quest for reality.
Most prominently there is a series of gauzy scrims across the stage, through which the audience views the play, and which function to render the town air mist-thick, the visibility hazy.
The mode is highly theatrical, beginning with a drawn red curtain at the back of the stage through which dancers enter and exit.
The multilevel, multifarious stage through which Mr. Murphy runs and jumps and (almost) levitates becomes the apparatus of memory itself.
They put opaque layers of ornament between street and stage, through which the paying customer would be ceremoniously conducted.
Atienza's participation was crucial – the derivation was picking up speed and moving towards the "passaging" stage through which the cell lines are divided and transferred to new culture dishes.
This brings me to my third and final stage through which biotech companies must pass on their way to becoming stock market winners.
