Cloud & DevOps

Ship Faster, Safer: A Guide to Feature Flags for Canary Releases & A/B Testing

Decouple deployment from release. Learn how Meerako uses Feature Flags (e.g., LaunchDarkly) for safe rollouts, canary releases, and backend A/B testing.

Jessica Wu
AWS Certified Architect
October 29, 2025
11 min read
Ship Faster, Safer: A Guide to Feature Flags for Canary Releases & A/B Testing

Ship Faster, Safer: A Guide to Feature Flags for Canary Releases & A/B Testing

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Meerako — Dallas-based DevOps experts implementing modern deployment strategies like Feature Flags.

Introduction

Traditional software deployment is risky. You merge a big new feature, deploy it to production, and pray nothing breaks. If it does, you have a frantic rollback, downtime, and unhappy users.

Modern DevOps practices aim to reduce this risk. One of the most powerful tools is Feature Flags (also known as Feature Toggles).

A feature flag is essentially an if statement in your code that allows you to turn features on or off in production without deploying new code. This simple concept unlocks incredibly powerful deployment strategies.

At Meerako, we leverage feature flags (often using managed services like LaunchDarkly or Flagsmith) as a core part of our CI/CD pipeline. This guide explains how.

What You'll Learn

  • What a Feature Flag is.
  • How flags decouple deployment from release.
  • Using flags for Canary Releases (gradual rollouts).
  • Using flags for Backend A/B Testing.
  • Why managed services (LaunchDarkly) are often better than DIY.

What is a Feature Flag?

It's as simple as this (pseudocode):

// Check if the 'new-dashboard' feature is enabled for the current user if (featureFlags.isEnabled('new-dashboard', currentUser)) { // Show the new dashboard component renderNewDashboard(); } else { // Show the old dashboard component renderOldDashboard(); }
The magic is that the isEnabled check doesn't involve a code change. It typically queries a remote configuration service (like LaunchDarkly) which allows you (the product manager or engineer) to control who sees which version via a web UI.

Benefit 1: Decouple Deployment from Release

  • Traditional: Code Deploy = Feature Release.
  • With Flags: You can deploy the code for your new feature (wrapped in a flag, turned off by default) safely into production weeks in advance. The code is live, but no users see it. When marketing is ready for the big launch, you simply log into the feature flag UI and flip the switch to 100%.
  • Result: Reduces the stress and risk of "big bang" releases.

Benefit 2: Canary Releases & Gradual Rollouts

  • The Problem: Releasing a major new feature to 100% of users at once is risky. What if there's a hidden bug?
  • The Solution (Canary Release): Use your feature flag service to release the new feature gradually:
    1. Day 1: Turn it on for Internal Employees only.
    2. Day 2: Turn it on for 1% of all users.
    3. Day 3: Turn it on for 10% of users.
    4. Day 4: Turn it on for 50%...
    5. Day 5: 100% rollout.
  • Result: You can monitor performance and errors (using your observability stack) at each stage. If you see problems at 10%, you can instantly flip the flag off and only 10% of users are affected. No frantic rollback needed!

Benefit 3: Backend A/B Testing

A/B testing isn't just for button colors! You can use feature flags to test different backend logic.

  • Example: You have a new AI recommendation algorithm. Use a flag to send 50% of users to the old algorithm and 50% to the new one. Track which group has a higher conversion rate.
  • Result: Data-driven decisions about complex backend changes.

Benefit 4: Kill Switches & Maintenance Mode

  • Kill Switch: Is a specific feature causing unexpected server load? Instantly disable just that feature with its flag, without taking the whole site down.
  • Maintenance: Need to take a specific part of your app offline for maintenance? Wrap it in a flag and turn it off.

Why Use a Managed Service (LaunchDarkly, Flagsmith)?

You could build your own feature flag system (e.g., using a database table). Don't.

Managed services provide critical features out-of-the-box:

  • Sophisticated Targeting Rules: Release features based on user attributes (email, location, subscription plan), percentage rollouts, etc.
  • Audit Logs: See who changed which flag and when.
  • Performance: They have globally distributed infrastructure to serve flag evaluations in milliseconds.
  • SDKs: Pre-built libraries for every language (Node.js, React, Go, etc.).

Meerako's Choice: We often recommend LaunchDarkly for its enterprise-grade features, or Flagsmith (which offers a self-hosted option) for clients needing more control.

Conclusion

Feature flags are a cornerstone of modern, safe, continuous deployment. They transform releases from high-risk events into low-stress, controlled experiments. By decoupling deployment from release, enabling gradual rollouts, and facilitating backend A/B testing, feature flags allow your team to ship faster and with more confidence.

At Meerako, we integrate feature flagging into our CI/CD process to ensure our 5.0★ clients get the benefits of both speed and stability.

Ready to implement safer, more flexible deployment strategies?

🧠 Meerako — Your Trusted Dallas Technology Partner.

From concept to scale, we deliver world-class SaaS, web, and AI solutions.

📞 Call us at +1 469-336-9968 or 💌 email [email protected] for a free consultation.

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#Feature Flags#CI/CD#DevOps#Canary Release#A/B Testing#LaunchDarkly#Meerako#Dallas

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About Jessica Wu

AWS Certified Architect

Jessica Wu is a AWS Certified Architect at Meerako with extensive experience in building scalable applications and leading technical teams. Passionate about sharing knowledge and helping developers grow their skills.

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