Illustration of the TSNPE algorithm applied to our pulsar population synthesis. Here, we show results for inferring the five magneto- rotational parameters (as for Paper I) of the observed neutron star population in Experiment 1 with 1000 simulations in round 1. Each row corresponds to one round of inference. The last column shows the coverage probability computed on the test dataset. In each panel, the current round’s computed values are shown in blue, while values from previous rounds are shown in light grey. The grey shaded area in the one-dimensional marginal posterior represents the 95% credibility interval of the approximated posterior for that round. In each of these 1D marginal posterior distributions, the horizontal axes represent the parameters’ prior ranges. For comparison, the posterior distribution estimated in Paper I is shown as black solid lines.