The GigaTracKer is a hybrid silicon pixel detector designed for the fixed-target experiment NA62 at the CERN SPS aiming to measure the branching ratio of the very rare kaon decay $K^+ \rightarrow \pi^+\nu \bar{\nu}$ with 10\% precision.
The detector has to provide measurements of momentum, direction and time of beam particles arriving at a rate of 750 MHz.
The tracking system consists of four stations installed in vacuum ($\sim10^{-6}$ mbar), $60.8 \times 27\ \text{mm}^2$ each, with a total material budget of less than 2X$_0$.
Each station is cooled with a microchannel cooling plate used for the first time in a high energy physics experiment.
The beam particles are tracked in 4 dimensions by means of time-stamping pixels ($300\times300\ \mu \text{m}^{2}$) with the single hit time resolution reaching 115 ps.
This performance has to be maintained despite the beam irradiation amounting to a yearly fluence of $4.5 \times 10^{14}\ 1MeV\ n_{\text{eq}}/200\ \text{days}$.
The detector has been fully operational since 2016.
We describe the GigaTracKer design and performance in the 2016-2022 years of NA62 data taking.