Deno Cron

I think the answer to that is the same as the answer to "how do I send an email in Deno?", since this lets you run arbitrary code.

System level cron needs that feature built in because you're just telling it a command to run, and you're limited in how you deal with error and output handling of that command. That's not a problem when you're in the language you're using to define the action. Just catch your errors, or grab all STDOUT/STDERR with some solution and do with it what you want on success or error.

The downside is that when it has to be done on a job-by-job basis, you can’t rely on the cron system handling failure modes you didn’t anticipate.

It's code. There is not necessarily a single solution that makes sense. The thing you're calling could throw an exception, or it could return a failure value. If it fails, you may want to set off some extra routine that retries, or perhaps you want to handle some specific errors and retry or notify, but other errors are critical and cause failure, not just notification. Having it handle those automatically is not a feature in some cases, it's a problem.

System cron is simple, by design, because as a DSL there's a benefit to not complicating it. If you're already in Javascript/Typescript, a lot of the benefits of that are mitigated by the benefits of having much more control over exactly how it functions in every care.

As an example of this, there's a bunch of cron "helpers" to deal with the shortcomings of cron's simplistic approach, such as those in moreutils[1].

P.S. Personally I wouldn't have even called this implementation cron and use the cron syntax for it, since that just makes people assume cron usage and the cron scheduling format is not an asset if you're already in a language where you could just pass in a structure with the specific fields you want set by name.

1: https://rentes.github.io/unix/utilities/2015/07/27/moreutils...

I am a lead on a small startup team and one of the biggest pain points is dealing with infrastructure. We have no dedicated devops person and much of that work falls on me and other people who would be better writing code. I think the cloud paradigm is experiencing a shift. Few of us want to deal with cloud infrastructure (whether clicking around or via Terraform or equivalent) to execute a function every X minutes - its unnecessary developer hours. The functionality is so common that it should just work. Perhaps stemming from that there seem to be two recent trends:

1. Services like this cron with Dyno Deploy or Vercel where the cloud things are abstracted away for you.

2. I have no data to back it up but it seems like JVM is experience a bit of a comeback with a few companies adopting Kotlin for backend and, also subjectively, talk about Elixir has increased here on Hacker News (we've all seen that table that shows how the Erlang VM is cron/background jobs/logging service/KV store all rolled into one). And if those are not the trends I feel like they should be.

Both of those are very appealing to me as a team lead. Honestly, I have never been a fan of managing services in AWS/GCP/etc - the setup overhead rarely seemed to outweigh the pros, at least until some heavy amount of data start moving around. I might be stating the obvious - less work is definitely better, but pretty much every company I have consulted for in the last few years had a (crappy) bespoke cloud setup that was a massive time sink.

> How exactly does Deno Deploy know there’s a cron in your code, even when there’s no web server handling requests?

> When a new production deployment of your project is created, an ephemeral V8 isolate is used to evaluate your project’s top-level scope and to discover any Deno.cron definitions. A global cron scheduler is then updated with your project’s latest cron definitions, which includes updates to your existing crons, new crons, and deleted crons.

Having cron jobs defined in the code itself just feels weird. I get the convenience of doing things "in one place", but it's such an orthogonal concept. But I suppose combining things is part of the allure of deno any way.

Now that aside, the Flavor Flav dinosaur is the best thing I've seen all week.