Fly.io: The reclaimer of Heroku's magic

1. Multi-region deployment only work if your database is globally distributed too. However, making your database globally distributed creates a set of new problems, most of which take time away from your core business.

2. File persistence is fine but not typically necessary. S3 works just fine.

It's easy to forget that most companies are a handful of people or just solo devs. At the same time, most money comes from the enterprise, so products that reach sufficient traction tend to shift their focus to serving the needs of these larger clients.

I'm really glad Heroku froze when it did. Markets always demand growth at all costs, and I find it incredibly refreshing that Heroku ended up staying in its lane. IMO it was and remains the best PaaS for indie devs and small teams.

Guess what? fly.io offers a turnkey distributed/replicated Postgres for just this reason. You use an HTTP header to route writes to the region hosting your primary.

https://fly.io/docs/getting-started/multi-region-databases/

You do still need to consider the possibility of read replicas being behind the primary when designing your application. If your design considers that from day 1, I think it takes less away from solving your business problems.

Alternatively, you can also just ignore all the multi-region stuff and deploy to one place, as if it was old-school Heroku :-)

Doesn't this take away a lot of the benefits of global distribution?

For example if you pay Fly hundreds of dollars a month to distribute your small app in a few datacenters around the globe but your primary DB is in California then everyone from the EU is going to have about 150-200ms round trip latency every time you write to your DB because you can't get around the limitations of the speed of light.

Now we're back to non-distributed latency times every time you want to write to the DB which is quite often in a lot of types of apps. If you want to cache mostly static read-only pages at the CDN level you can do this with a number of services.

Fly has about 20 datacenters, hosting a small'ish web app that's distributed across them will be over $200 / month without counting extra storage or bandwidth just for the web app portion. Their pg pricing isn't clear but a fairly small cluster is $33.40 / month for 2GB of memory and 40GB of storage. Based on their pricing page it sounds like that's the cost for 1 datacenter, so if you wanted read-replicas in a bunch of other places it adds up. Before you know it you might be at $500 / month to host something that will have similar latency on DB writes as a $20 / month DigitalOcean server that you self manage, Fly also charges you $2 / month per Let's Encrypt wildcard cert where as that's free from Let's Encrypt directly.