BC547 Transistor based Logic level converter reliability in Industrial Applications
That circuit is a single-transistor bidirectional buffer. I would put a 1k-10k resistor between 3V3 and emitter as well, by the way. Note that this circuit should be used for comm lines that are kept high on idle (e.g. UART RX/TX).

If the speed is low enough (say, 57.6kBaud) then it will work. Input capacitances of the transmitter and receiver nodes play role as well.

PS: I'm using BC237/BC817 for low-distance (max. 3-meter-long) comms with speeds of under 100kHz.