A conduit pulls information from earlier conduits in the same pipeline, only requesting the next item when it needs to do more work in order to process a request for a value from a conduit later in the pipeline. This means that inside the conduit itself there is perfect backpressure: you cannot overload any buffers between conduits because there aren't any.
Of course, depending on the rest of the system you could still have a bottleneck somewhere. For example: if you pull jobs from a queue in (say) Redis but don't have enough capacity to process jobs faster than they are enqueued, the queue will eventually fill up.
Of course, depending on the rest of the system you could still have a bottleneck somewhere. For example: if you pull jobs from a queue in (say) Redis but don't have enough capacity to process jobs faster than they are enqueued, the queue will eventually fill up.