How many words do you need to know to start learning only in English?

Question

English learning tools

When meeting English text I use the plugin. I tried to read in English, writing down unfamiliar words. I don't know about 30% of the words, 15% of the 30% I heard, saw, translated, but didn't remember. Moreover, the content of the texts was quite trivial. The section about one service and article on technology which I studied last week.
If every time you climb into the translator, and even try to remember these words, then probably no one will survive. Not to mention the understanding of the text.
I decided to check my vocabulary on this service - testyourvocab.com. I got 3500 words, I also passed in Russian - 55k, passed English with the help of a plugin - 40k words (for a native speaker 30-35). How many words do you need to know in order to "learn" only in English without the help of a translator?
Learn = ask/answer/read questions on stackoverflow, read articles on sites similar to Habr, read documentation (not only on technologies already studied in Russian, but also on new ones).
Perhaps there is a way to learn exactly useful words? (Just do not recommend English books in IT, I know all the words that are there).
The prospect of learning 30,000 words is certainly not encouraging when I know 3500 English in 10+ years.

Answer 1

You know 3500 words and you can't understand the text without a dictionary... it's strange somehow. Your problem is most likely not in this.

Answer 2

Up to 5000 words you need to know + understand by ear more