Estonia's DNV is a visa, not a tax product. If you stay long enough or create sufficient ties, Estonian tax residency can become relevant.
183-day rule
Estonia generally treats individuals as tax resident if they stay in Estonia for at least 183 days over 12 consecutive calendar months. Tax treaties can change the final answer when two countries claim residence.
Foreign company vs Estonian company
Do not confuse the DNV with e-Residency. E-Residency helps manage an Estonian company online, but it does not grant residence. Running an Estonian company while living in Estonia can create different tax and corporate obligations from simply working for a foreign employer.