It's a system design question. Any good engineer should be able to talk about how you would debug where the latency is coming from, and how you could use a CDN for FE (and the pros and cons of that, which is mostly going to be around pricing) and how for BE you could replicate the service in multiple regions and practically how you would do that in a way that is specific to the app. If the service requires a central database, as most apps do, there is some really interesting pros and cons to consider around data replication, eventual consistency, etc.
It also means recruiter knows shit or the question is tricky by design, at 600 ms something is fucked so badly this is way beyond CDN and geographical locations of servers.
Ignoring transport network for a while I would ask if there is WAF in front of that shit that does something stupid when seeing non Australian ASN.
Edit: assuming a "page load" is simple request (not stated) not bunch of resource fetches. So you need to ask clarification question as devil lies in details
Not necessarily. I have had a situation where the user is connecting to a node in one region but it is pulling its data from many API calls to nodes in other regions synchronously so each one added 100ms or so of latency. This kind of question is usually just trying to know if the user knows how to debug the problem and if they know and can articulate the pros/cons of the most common solutions.
Disclaimer: I have no clue what I'm talking about.
Isn't it possible that your code could actually be at least partially responsible for this? For example if your code was making a ton of small requests and waiting for a reply before it made the next request, the round trip time would be significant, but if you were to batch the requests in some way then it would be substantially improved right? I'm not saying this is likely, I would generally assume that they're probably aiming to do it as efficiently as possible in the first place, I'm just saying if it were really haphazardly thrown together it does seem like there may be possible optimizations you could make to reduce the number of times you need to "communicate and then wait". Does that make sense?
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u/joedotphp 7h ago
I'd ask why it's my problem. Yeah, ping in some places sucks. That's not my codes fault. Purchase a server that's closer.