Nothing out of the ordinary here.
Are the 502 responses, tied to a specific input? (Perhaps a very long translation?) Is there a pattern to them? Does the problem happen if you make the requests one at a time instead of in parallel?
Edit: I did find a timeout setting for our wsgi workers that was set to 30s (it should have been 60s instead), perhaps that’s the cause.
Ok! Do you need to restart the servers? Or the changes will be directly applied?
They are already applied. But I’m still noticing some timeouts happening.
Perhaps we might have to adjust the maximum number of characters that we can reasonably process within 60s.
Our requests are maximum 4950 characters and we do not do more than 80 requests per minute.
After some more investigation, I think the root cause here is that our servers are unable to come up with a translation within a reasonable amount of time (60s). I’ve adjusted our offering to limit the number of characters to 2,000 per request. I apologize for this, we’re figuring out these limitations as we go. I can offer you a refund for your API key purchase if the new limit is not acceptable for your use case. 
It’s ok. Just needed to know the rules to optimize what we can do. Thanks!
@pierotofy I am almost done with my translation requests, but wanted to give you guys some feedback as that the parameters advertised are not meeting real life usage. I think it should be clearer what we can expect with the paid API. You mentioned you have put the timeout at 60 sec, but on the user’s end, it never goes beyond 51 seconds. Also, we are nowhere close to attain the theoretical limit of 2000 characters per request. In fact, many requests below 1500 characters hit the 50.12 sec limit and therefore, obtain a 520 response from the server. I can give you access of my logs if needed. Cheers.
Hey @miherb 
thanks for the feedback. I’ll look into the 520 response timeout. We definitely don’t want that to happen and I apologize for the issues; if you have suggestions on how we can better communicate expectations please get in touch.
Edit: I’ve bumped some timeout settings in the server settings, let me know if the issue persists?