The initial offers are often higher than 400 for Senior Software Eng, Senior Data Scientists, Senior Machine Learning Research Scientists and Engineers. 600 is actually pretty common for experienced people. On paper, there are no Juniors (there are associates in Marketing and Business and I think other teams). They pay top of the market according to their Excel sheets.

Netflix does not have "tech lead" or "Principal" roles for the Software or Science teams. It is Senior, then you have Managers (who can be paid less than Seniors), Directors (no senior Directors), VP (no Senior VPs), and C-suite (with comp that is publicly available).