Large Segments, Targeted Impact: Controling Feature Rollouts at Scale

Releasing new features at enterprise scale isn’t just about flipping a switch—it’s about precision, control, and managing complexity at an enormous scale. Imagine trying to roll out a critical update to millions of users, or needing to target a specific subset of customers impacted by a security incident. Most feature flagging tools and homegrown solutions simply can’t provide this level of segmentation.

That’s why Harness Feature Management & Experimentation (FME) introduced Large Segments—unlocking a new level of control for enterprise teams looking to target and release features at scale, without the headaches of managing massive user lists manually.

Why Enterprises Need Feature Management at Scale

According to a recent survey conducted by LeadDev, 42% of enterprise customers are still building and maintaining their own homegrown feature flag tools. While DIY solutions might work for startups or small-scale applications, they fail to meet the demands of enterprise-scale experimentation and rollouts.

Here’s why:

• Security & Performance Risks: Homegrown tools often lack the security, governance, and infrastructure necessary to operate at enterprise scale.
• Experimentation Bottlenecks: Enterprises need to safely test and validate features before full rollout, but DIY solutions often lack robust A/B testing capabilities.
• Phased Rollouts Are a Nightmare: Without an enterprise-grade feature management system, targeting millions of users in waves (e.g., 10% → 25% → 50%) becomes a time-consuming, manual process. 

The further your enterprise grows its digital initiatives, the more managing releases and experiments becomes a logistical nightmare. If you want to experiment, target, and release safely and efficiently, it’s time to embrace a solution built for enterprise-scale feature management with large segmentation capabilities.

Scaling Beyond Traditional Segments

Typically, feature flagging tools allow for small to medium-sized segments, often limited to a few thousand to a few hundred thousand users. But what if your business has 100 million users? How do you efficiently roll out new features or address urgent issues without sinking time into manual targeting?

This is where Large Segments built for enterprise-scale come into play. With Large Segments from Harness FME, you can:

• Target up to 1 million users per segment (expandable to 10 million or more).
• Instantly roll out or roll back features for massive user groups.
• Use pre-built user lists when attribute-based targeting isn’t feasible.

Here are real-world examples:

Imagine a data breach affecting 2 million users of a financial services app. You don’t want to notify unaffected customers—just those impacted. Large segments allow you to create a group of affected users based on imports. Then, you can serve them a targeted notification in-app, offering guidance or security updates. In the end, you’ll ensure a seamless, controlled response, without disrupting the experience for the other 20 million users.

Or, let’s say you’re an eCommerce site launching a new AI-powered recommendation engine. With Large Segments, you can first roll out the feature to 1 million high-value customers, analyze engagement and sales impact, then expand to 10 million casual shoppers, ensuring performance and user experience remain stable before a full release.

This isn’t just adding a little precision to your game; this is huge.

6 Benefits of Large Segments

Large Segments by Harness FME is designed to simplify, speed up, and scale enterprise rollouts and experiments. Here’s how:

1. Faster, Safer Feature Rollouts–In the Millions

With Large Segments, you can enable features for millions of users simultaneously, eliminating the need for slow, incremental updates. This ensures that high-traffic applications maintain stability while rolling out new functionality. It also allows for seamless phased rollouts, such as enabling a feature for 10% of users, then expanding to 50%, and eventually reaching 100%—all while monitoring impact and mitigating risk.

2. Targeting at Large Segments Without Slowing Down Apps

Traditional segmentation methods often rely on database queries that slow down application performance, but Large Segments are optimized for speed. By eliminating these costly lookups, rollouts happen almost instantly, even at an enterprise scale. Updates to segments also occur in real time without requiring redeployment, ensuring teams can adapt quickly without disrupting user experiences.

3. Experimentation on a Massive Scale

Running A/B tests or canary deployments is more effective when you can target large, statistically significant user groups. With Large Segments, enterprises can confidently experiment with millions of users, gathering meaningful insights that lead to data-driven decisions. This ensures that product teams have enough data to measure impact before rolling out features more broadly.

4. Consistent User Experiences

Large Segments ensure that users included in a rollout experience the same feature behavior across all devices and sessions. This prevents issues like “flag flapping,” where a user unpredictably toggles between feature variations due to inconsistent targeting. By maintaining a stable and predictable feature experience, companies can avoid frustrating inconsistencies that impact customer trust.

5. Granular Control Without Complexity

Managing enterprise-scale feature rollouts doesn’t have to involve complex rules or extensive engineering effort. Large Segments allow teams to define user groups based on uploaded lists, making it easy to target specific audiences without writing custom logic. This empowers non-technical teams, such as product managers and marketers, to manage segmentation efficiently without relying on developers.

6. Enterprise-Ready Governance & Security

Enterprises operating in regulated industries require strict governance and compliance controls for feature rollouts. Large Segments help organizations meet requirements like GDPR and CCPA by allowing precise user targeting based on regulatory needs. Additionally, with built-in approval workflows, audit logs, and role-based access controls (RBAC), teams can maintain security while ensuring that only authorized personnel can modify or deploy critical updates.

Large Segments With Harness FME

Large Segments are available to enterprise-tier Feature Management & Experimentation customers.

• Supports up to 1 million keys per segment by default (expandable to 10M+).
• All segment types are now in one place, with a visual indicator of segment type.
• Works client-side only for now (server-side support coming soon).
• Upload entire data files in one go, rather than incrementally.
• Immutable by design, meaning segments cannot be changed once created.

For enterprises, this means greater control, faster experimentation, and more powerful rollouts—all at an unprecedented scale.

Want to learn more? Talk to our team at Harness and see how Large Segments can revolutionize how you release features at scale.