Logging is one of those things that remains mostly an afterthought for a lot of languages, frameworks, and engineers. It's not that hard to get organized. Here

Logging is one of those things that remains mostly an afterthought for a lot of languages, frameworks, and engineers. It's not that hard to get organized. Here's what I've been doing since the last ten years on most of my projects (Java & Kotlin mostly but you should be bale to do this for anything). 1) log levels matter. Debug/tracing is disabled in production. Info is informational only and should not have a signal to noise ratio that gets annoying (people doing debug logging at info level). Warning frequency should be low. If you are not going to fix it, it's not worthy of a warning. Errors should cause alerts and people to be woken up. Simple rule but only if you enforce it. Don't log at error level unless it really is worth waking somebody up for (e.g. me). An error is not "something totally expected happened but I could not be arsed to think about handling that in a sane way". I've seen projects that routinely log thousands of errors per hour and never fix anything until after customers start yelling on the phone. Log levels are totally irrelevant in such projects. Nobody bothers to look at those errors. They are no longer actionable. If errors are normal and expected behavior, how do you tell when something abnormal and unexpected happens? You can't; unless you make people do something about those errors and create a culture where having errors is simply not an acceptable state for the product to be in. Life is great when you do that. We have zero errors on most days. When they do happen, it's usually because something changed. And then we fix that and it goes quiet again. Simple rule to enforce. Generates very little work. But you have to enforce it. 2) Java logging frameworks have something called a mapped diagnostic context (MDC). This is great. Basically it means every log entry can have a context where you can keep track of things in e.g. your request like headers, user agents, ip addresses, session ids, etc. Why don't other languages have this? I don't know. Seriously, how is this not a thing for any web development framework worthy of the name. Why would you not want to know this information when something happens? 3) Logging messages are structured data. Whether you like it or not. Plain text is a shitty way to represent structured data. If you can, log in json format. You have timestamps, logger names, log levels, attributes in your MDC, attributes coming from your server environment like the host name, service name, etc. All of it is relevant. 4) Tailing and grepping plain text logs simply does not scale. It's what you have to do when your ops team is too incompetent to setup proper logging. Usually goes hand in hand with having snow flake servers that people ssh into. It's actually the #1 excuse to have boxes you can ssh into to begin with. Solution: logs go into a data store that allows you to filter on this data. Not having this is the equivalent of running blind. Completely and utterly unacceptable. Most cloud environments come with a reasonably OK logging console but you might want to upgrade to something with a bit more querying capability. But done right even those default logging consoles can be capable enough. 5) Your logs should have alerts on them. If errors happen, alerts should happen and people should do things about those errors. If logs go silent when they shouldn't be, alerts should happen because something is probably broken. If there's a weird spike in logging volume, alerts should happen. Alerts should be actionable and be exceptional. If something is alerting all the time, nobody will check when something important actually does happen. Tricky to get right but once you do, you can react quickly to any incidents. Deliberately keeping product names out of this. There are plenty of libraries, tools and products that allow you to do this properly. That most likely includes your preferred software stack. And if it doesn't, use something more production ready that does. Or fix it (not that hard usually).