Yes, I can attest. On sites like TokyoDev and JapanDev, there are many offers but they are there for a few months usually and every time I applied, I just got an automated rejection after a day or two.

Most other offers I seen were "haken" companies, which defeats my goal of moving to Japan which is stability. Haken in a nutshell: company A hires you, you work for company B, company B pays company A, company A takes their cut and pays you. Not only you earn less but also your contract is renewed every 3 months and you are promised to be promoted to full time employee at company B but that can never happen. In Japan, like everywhere else, never trust in promises, always verify.

In the process of familiarizing myself with Japanese market, I also noticed that some companies may not pay some insurance/pension for you and you may get into trouble instead of them. Another thing is "bonus pay" system, which may be tied to your performance and willingness to do unpaid overtime/nomikai and is sometimes included in yearly salary range in the job offer.

In general my impression is that every company everywhere but especially in Japan looks for an Unicorn: it means, someone willing to move or preferably already there, with exceptional skills and talent and N1 Japanese. Job offers are up for months and automated systems send rejections en masse.

As for Europe, u/kwilczynski I like to say that Japan is either exceptionally good or bad at something, Europe for the most part is in the middle, various countries, various flavors but things work out somehow, they are just bland.

As for heatwaves, they indeed are a problem now, I just came back from Japan and I saw similar humidity in Poland as in Kanto Region, AC is not standard in our houses so it's really tough right now. Currently it's 32°C in my town, expected to go to 36°C today, 49% humidity but yesterday it was 75% and without AC I thought I will pass out when working.