[delayed]

Launch Darkly charges on volume across multiple dimensions, including MAU and server-side connections, plus log, trace and error counts. It's bonkers and anyone who can actually predict what it will cost (good luck) will run away as fast as they can.

There is no way a Feature Flag system is a multi Billion dollar company based on the tech, and if there IS a Saas-pocalypse it's coming for players like LD first.

What would you recommend as an alternative?

Unleash Cloud ?

Put flags in your own DB(s)?

What if your DB is down?

Have a safe default fallback.

Wouldn't you be having bigger problems if the DB is down (especially if you have good defaults for the flags)?

My website company 20 years ago was running Memcached keys for each of the feature flags so they only had to be loaded about once per session from the DB most of the time.

Scaling things like this is a mostly solved problem. Having your website load when the DB is down is not.

Ex-LD engineer here. This was a classic mistake we saw most of our customers make, before they had to switch to LD or its competitors when they scaled a little bit more. Using a db is fine but can put heavy load on the server depending on the number of flags. In addition, it doesn't give you various features such as tagetting by users, segments, etc. Nor does it give you things like progressive rollout or automated rollback (yes we were using that in house and had saved us at least a few times).

I'm not advocating for LD, I'm advocating for any feature management system.

I've designed such a "classic mistake".

> In addition, it doesn't give you various features such as tagetting by users, segments, etc. Nor does it give you things like progressive rollout or automated rollback (yes we were using that in house and had saved us at least a few times).

These are things you can think of quite easily, or you just survey the landscape of what challenges other implementations run into and they inform you of this. The first iteration of our design had all of those; we could target users, always-subscribe internal users, we could have two features have the same segment/ordering of rollout, etc.

Database load wasn't ever a problem, because you're talking about quite literally a single SELECT on an already established & otherwise in use DB connection. But caching is not that much to bolt on afterwards should it become an issue.

It's never been clear to me that the simplicity of understanding that a single query has, even if it might be short a few features, is outweighed by the complexity of a full dependency to an external service.

As it was, our FF system outlived the company, and was sunset when the company ended.

Eh, I built a feature flagging system for service with millions of daily active users and it: wasn't hard to do, was easy to extend to support targeting, segments, and progressive rollout, and on top of it flags are easy to cache, so the database pressure was not that big. We did this long before LLMs, and it occupied maybe a month of engineering time for me, here and there as we needed new features, while I was doing other things. We did choose the wrong hash for bucketing in the beginning, but we noticed the stairstep patterns in our buckets quickly (an advantage of having millions of requests per day to measure) and picked a better one. It was much better this way since it meant backend flags without a roundtrip to a 3rd party service (that was the main motivation, we wanted this kind of control without adding latency to our requests). I remain baffled by launch darkly or other such services. And today, with LLMs, just build it yourself is hard to argue against.

As I mentioned, I'm not advocating for LD. I'm advocating for feature management systems (over env vars/db values and other similar naive implementations). The build vs buy is a separate argument.

> that was the main motivation, we wanted this kind of control without adding latency to our requests

Right, and most, if not all, off the shelf feature management systems have this problem solved already. For example LD uses a streaming architecture by default to push out flags to your application within 200ms. I believe Unleash does something similar.

this was almost a decade ago, the options were imo pretty bad

Posthog is absolutely awesome. Its free tier is insanely generous too .91% of its users don't pay anything or something. We use it at a startup I'm involved in (~5k MAU) and we have never paid a penny which I am constantly surprised by since it's such a backbone for us.

There are a number of providers that provide flat-rate or near flat-rate pricing in this space. I'll go ahead and recommend featureflip.io as one such example. ConfigCat is another common one.

I am affiliated with featureflip but it does a ton of the same things for a sane price.

I've built GO Feature Flag and we have built everything on top of OpenFeature since we believe that the standard is the only way to go.

The main difference is that we have a gitops approach where all the changes are in a file and no UI is needed. You can host your feature flags where you want (S3, github, GCP, ...) you don't need to run a database or pay per MAU at all.

It's MIT-licensed with no paid tier: [gofeatureflag.org](https://gofeatureflag.org/?utm_source=hn)

This seems entirely too dismissive of what LaunchDarkly's service does.

I don't know about first. Feature flags is somewhere down the list, behind email and comms and scheduling and todo's. AI can vibe code the shit out of a Todo app. Google Workspace wants $7/$14/or $22 per user per month. Times 50 or 100 people, that's not insignificant. Closely behind that there's the (financial) books. QuickBooks is the 800 lb gorilla of that industry and everyone just goes with them because book keepers know how to use them. There's no shortage of competition, especially AI competition to replace the human bookkeeper with an LLM. We'll just have to see where things go though.

On Unleash Cloud: 100M request per month on Unleash cloud would be $235 + 75$ per seat ($53 Million requests included).

Shoutout to ConfigCat, https://configcat.com/

Same features as all these big guys, EU hosted, and down-to-earth pricing. Even the free tier got me quite far.

I'm unaffiliated btw.

The ConfigCat team is great!

Unleash also originates from Europe.

[delayed]