Why a Homegrown Feature Flag System is a Trap

Feature flags empower teams to ship code safely, experiment quickly, and decouple deploys from releases. At first glance, building your own feature flag system seems like a quick win: a few conditionals in your code, a simple database table, and you’re off to the races. But reality sets in as the system grows. Maintaining that DIY solution steals time and focus from your core product.

The Hidden Cost of “Build It Ourselves”

Your in‑house flag tool will demand far more than the initial build. You’ll need to maintain APIs, update SDKs for new languages, scale the service, provide dashboards, handle audits, and add targeting rules. Every hour spent on these tasks is an hour not spent building differentiating features. Over time, that opportunity cost grows.

The Real Numbers Behind Maintenance

Many teams underestimate just how much time a home‑grown system will consume. Consider these data points:

• Engineers lose up to 30% of their time maintaining DIY feature flag tools^[1]. With a 40‑hour workweek, that equates to roughly 48–52 hours per month that could have been spent on core product development.
• A recent survey found that 70% of teams without commercial feature management spend more than 25% of their time on pre‑release testing and bug fixing^[2]
• Research on feature‑flag technical debt reveals that 73% of flags are never removed and that developers spend more than five hours per week navigating flag‑ridden code^[3]. For a ten‑developer team, that debt totals about 2600 lost hours per year, or around 22 hours per developer per month .
• Wayfair’s homegrown feature flag system cost the company over $3 million a year^[4] . By switching to a commercial platform, they cut that cost by two‑thirds.

These numbers make it clear: building your own feature flag system isn’t just a minor distraction, it’s a substantial drain on productivity and money.

The Bridge: OpenFeature

If you already have a home‑grown solution, you don’t need to throw it out overnight. OpenFeature offers an open standard that lets you wrap your existing system behind a common API. Think of it as Kubernetes for feature flags: a consistent set of SDKs that can switch between different backends. With OpenFeature you can:

• Keep using your current flags while migrating gradually.
• Add support for multiple languages and frameworks with standardized SDKs.
• Avoid vendor lock‑in by swapping providers without changing application code.

Example: Creating a Custom Provider

Here’s a simplified example in TypeScript showing how to wrap a home‑grown flag service with an OpenFeature provider. The provider fetches flag values from an internal dictionary but could easily call your own API or database.

// homegrown-provider.ts
import {
  Provider,
  ResolutionDetails,
  StandardResolutionReasons,
} from '@openfeature/server-sdk';

export class HomegrownProvider implements Provider {
  name = 'homegrown';

  async resolveBooleanEvaluation(
    flagKey: string,
    defaultValue: boolean,
  ): Promise<ResolutionDetails<boolean>> {
    // Replace with real DB or API call
    const flags: Record<string, boolean> = {
      'new-ui': true,
      'beta-mode': false,
    };

    return {
      value: flags[flagKey] ?? defaultValue,
      reason: StandardResolutionReasons.STATIC,
    };
  }
}

You register this provider and query it like this:

import { OpenFeature } from '@openfeature/server-sdk';
import { HomegrownProvider } from './homegrown-provider';

OpenFeature.setProvider(new HomegrownProvider());

const client = OpenFeature.getClient();
const enabled = await client.getBooleanValue('new-ui', false);
console.log(`New UI enabled? ${enabled}`);

This approach lets you standardize your flag API while still using your own backend.

Example: Migrating with a Split Provider

Once you’re ready to move away from your homegrown flags, you can plug in a commercial provider, such as Split, behind the same OpenFeature API. Here’s what that looks like:

import { OpenFeature } from '@openfeature/server-sdk';
import { SplitProvider } from '@openfeature/split-provider';

const splitProvider = new SplitProvider({
  apiKey: process.env.SPLIT_API_KEY!,
});

OpenFeature.setProvider(splitProvider);

const client = OpenFeature.getClient();
const enabled = await client.getBooleanValue('new-ui', false);
console.log(`New UI enabled via Split? ${enabled}`);

During migration you can even do a dual‑read strategy: call your homegrown provider first, then fall back to Split, and compare results. This incremental approach reduces risk by validating parity before switching fully.

import { MultiProvider } from '@openfeature/multi-provider'
import { OpenFeature } from '@openfeature/server-sdk'

const multiProvider = new MultiProvider([
  {
      provider: new ProviderA()
  },
  {
      provider: new ProviderB()
  }
])

await OpenFeature.setProviderAndWait(multiProvider)

const client = OpenFeature.getClient()

console.log("Evaluating flag")
console.log(await client.getBooleanDetails("my-flag", false))

Watch Jonathan Norris, CTO, DevCycle go through how to do this.

Commercial Providers: DevCycle and LaunchDarkly

After wrapping your DIY system with OpenFeature, you’ll want to adopt a provider whose core business is feature flags. DevCycle and LaunchDarkly are two strong options:

• DevCycle offers developer‑friendly workflows, experimentation tools, and a modern UI.
• LaunchDarkly provides enterprise‑grade compliance, advanced targeting, and a large ecosystem.

Both integrate seamlessly with OpenFeature, so migrating is as simple as swapping providers.

The Everyday DevOps Lesson

Building your own feature flag system might feel empowering at first, but the data shows it’s a costly detour. Teams spend dozens of hours each month maintaining infrastructure that doesn’t differentiate their product, and the opportunity cost grows as the system scales. The smarter path is to adopt OpenFeature early, wrap your existing system as a provider, and plan a gradual migration to a commercial platform. That way you keep your engineers focused on innovation instead of reinventing the wheel.