I have a 50min outbound and 55min inbound connection coming up (SFO-SIN-BLR; HYD-SIN-SFO). Typically I would not be very comfortable with such tight connections but my recent experiences connecting at Changi have been very efficient and I think it might be ok.

However I checked on flightaware today and SQ519 arrived late at 8:12pm and SQ34 departed at 8:21pm - so I am not sure I would have been able to make that connection.... but as the previous posts indicated SQ is good handling these situations.