Personalized Push Notifications: Dynamic Variables, Intelligent Delivery, A/B Testing

How Personalized Push Notifications Prevent CTR from Dropping?

Imagine: you send a push "20% off everything!" — CTR drops 15%, unsubscribes double. Without personalization, 80% of notifications remain unopened, and every second unsubscribe happens after the first message. True personalization means the notification includes the user's name, favorite category, and arrives during their habitual activity. Such notifications achieve CTR 1.5–2 times higher, with conversion reaching 25–35%. We've solved similar tasks for dozens of mobile projects, from e-commerce to fintech apps. For example, for a fintech app we boosted CTR from 8% to 22% in a month by implementing dynamic variables and Intelligent Delivery. Let's break down the technical implementation on the OneSignal, Firebase, and Braze stack. Get a consultation on your scenario — we'll help you choose the optimal solution.

How Dynamic Variables Solve Low CTR?

Dynamic variables in the payload are the foundation of personalization. OneSignal and Braze support templates with variables that the server renders before sending.

Example payload for OneSignal:

{
  "app_id": "YOUR_APP_ID",
  "include_aliases": { "external_id": ["user_88234"] },
  "headings": { "ru": "{{first_name}}, your favorite product is cheaper" },
  "contents": { "ru": "{{product_name}} now costs {{new_price}} — {{discount_percent}}% less" },
  "data": { "product_id": "{{product_id}}", "screen": "product_detail" }
}

Variable values are taken from user tags. The first_name tag is set on the client:

OneSignal.User.addTag("first_name", user.firstName)
OneSignal.User.addTag("preferred_category", user.topCategory)

Personalized Based on Behavior

This is more complex — it requires an analytics layer on the backend. A typical scheme:

1. The client logs events (product view, wishlist add).
2. The backend or ML service generates recommendations for the user.
3. When sending, the payload is enriched with recommended content.

If you don't have your own engine, use Firebase Personalization or Braze Recommendations. Example logging in Kotlin:

firebaseAnalytics.logEvent(FirebaseAnalytics.Event.VIEW_ITEM) {
    param(FirebaseAnalytics.Param.ITEM_ID, product.id)
    param(FirebaseAnalytics.Param.ITEM_CATEGORY, product.category)
    param(FirebaseAnalytics.Param.PRICE, product.price)
}

Why Intelligent Delivery Is Not a Luxury but a Necessity?

OneSignal Intelligent Delivery and Braze Optimal Time track activity patterns of each user and delay delivery until the period with the highest open probability. For one user it's 8 AM, for another it's 11 PM. It's enabled with a single parameter: "delayed_option": "last-active". A more precise version is "intelligent_delivery": true. According to our data, this increases CTR by 25–40% — the best result among all time-optimization methods.

How to A/B Test Push Notifications?

Without A/B, you can't claim personalization works. OneSignal supports native split tests: send multiple variants (e.g., two different headings), and after gathering statistics the algorithm automatically shows the winner. Example:

{
  "name": "price_drop_ab_test",
  "messages": [
    {
      "variant_id": "A",
      "contents": { "ru": "{{product_name}} got {{discount}}% cheaper" },
      "weight": 50
    },
    {
      "variant_id": "B",
      "contents": { "ru": "{{discount}}% off an item from your wishlist" },
      "weight": 50
    }
  ]
}

After the test, OneSignal shows CTR per variant. The winner is embedded into the template.

How to Set Up Personalization in 6 Steps

1. Integrate the OneSignal SDK (iOS/Android) or Firebase Cloud Messaging.
2. Set up user tags on the client: name, category, last visit.
3. Create push templates with variables {{first_name}}, {{product_name}}.
4. Enable Intelligent Delivery (OneSignal) or Optimal Time (Braze).
5. Run an A/B test with two heading variants and automatic winner determination.
6. Set up conversion tracking via outcome events.

Personalization Methods Comparison

Conversion Tracking

CTR is an intermediate metric. What matters more is whether the user performed the target action. For that you need outcome events:

OneSignal.Notifications.addClickListener { event ->
    val productId = event.notification.additionalData?.getString("product_id")
    OneSignal.Session.addOutcome("notification_click_to_product")
}

OneSignal.Session.addOutcomeWithValue("purchase_from_notification", orderValue.toFloat())

This links conversion to a specific notification. In our projects, post-click conversion reaches 35%.

Push Notification Platform Comparison

Common Personalization Mistakes

What Our Work Includes

• Audit of current notifications and metrics
• Setting up dynamic templates and SDK integration
• Enabling Intelligent Delivery and A/B tests
• Setting up conversion tracking (outcome events)
• Delivery documentation and 2 weeks of post-launch support

Timeline and Cost

Implementation of the basic set (dynamic variables, Intelligent Delivery, A/B testing) takes 6–10 business days. If a custom recommendation layer on the backend or integration with an external ML system is needed, timelines are discussed individually. Savings on notification costs from CTR improvement can reach 30% with our approach. Cost is calculated individually for your project.

Our experience: over 5 years in mobile development, more than 50 personalization projects delivered. Certified OneSignal and Firebase specialists ensure quality.

Order an audit of your push notifications — contact us. We'll assess your project for free and suggest a solution. Get a consultation on your scenario — we'll help you choose the optimal solution.

Push Notifications in Mobile App: APNs, FCM, Segmentation, Rich Push

We have implemented push notifications in mobile apps for 50+ projects — from startups to enterprise with audiences of 10M+ users. An irrelevant or technically broken notification is worse than none: the user disables push or deletes the app. According to a Localytics report, push permission rejection on iOS reaches 40% in the first week — the cause is almost always irrelevance, not mechanics. Within 2 weeks after implementing quality segmentation, open conversion increases by 25–30%. Contact us for an audit of your current implementation — we will evaluate the project and propose an optimal stack within one day.

How the Infrastructure Works: APNs and FCM

APNs is the only delivery channel on iOS. Everything else (OneSignal, Braze, Airship) is a wrapper on top of it. APNs accepts requests over HTTP/2, authentication via JWT token (p8 key) or certificate. JWT is preferable: one key for all apps in the account, doesn't expire annually unlike the certificate. For more details, see the official documentation.

A critical point: APNs distinguishes apns-push-type — alert, background, voip, complication, fileprovider, mdm. An incorrect type on iOS 13+ causes background notifications not to wake the app. We've seen projects where content-available: 1 was sent without apns-push-type: background — the app didn't receive silent push on some devices, and the team spent a month looking for an 'app bug'.

FCM on Android works through Google Play Services. For devices without GMS (Huawei, part of the Chinese market), Huawei Push Kit or a direct WebSocket is needed — a separate task. FCM supports data messages (handled in onMessageReceived) and notification messages (the system displays automatically if the app is in the background). Mixing them requires caution: if the notification block has a click_action but the deep link is not registered in the app, tapping the notification simply opens the main screen without navigation.

Why Segmentation Is the Foundation of Effective Push Notifications?

Sending to everyone indiscriminately quickly exhausts user loyalty. Personalized messages are clicked 3 times more often than bulk ones, and proper segmentation reduces churn by 25% (on one project it brought significant additional revenue per quarter). The cost of setting up segmentation in OneSignal or a custom backend depends on the complexity of filters.

Proper segmentation is built on several levels.

Topics are for broad categories: 'new promotions', 'order status updates'. User subscribes via FirebaseMessaging.getInstance().subscribeToTopic("orders"). Simple, but no flexible filtering.

Attribute-based segments — via OneSignal, Braze, or custom backend. We store in the user profile: language, device type, last activity, LTV segment. Notification goes only to those with last_active < 7_days and plan = premium. OneSignal allows building such filters in the interface without code.

Personalized — by specific device_token. It's important to store tokens correctly: the token updates on app reinstall, restoration from backup on a new phone, or resetting settings. On iOS, use UNUserNotificationCenter + didRegisterForRemoteNotificationsWithDeviceToken, save to backend on every launch, not just the first. Otherwise, after 3 months 30% of tokens in the database are outdated.

What Is Rich Push and How Does It Boost Conversion?

A standard notification with title and text is clicked less often than a rich push with image and action buttons — by 3 times. But implementing rich push is a separate task on each platform.

On iOS, rich content requires UNNotificationServiceExtension (to modify payload) and UNNotificationContentExtension (custom UI). The extension runs in a separate process with limited time and memory. If the extension crashes or exceeds the timeout, the system shows the original payload without media. A typical mistake is trying to load an image over HTTP (not HTTPS): ATS blocks the request, the extension silently fails, and the user sees a notification without an image.

On Android with API 26+, notifications are tied to NotificationChannel. If the channel is created with IMPORTANCE_LOW, sound and vibration are unavailable. Different notification types (transactional, marketing) should be in different channels so the user can disable marketing without losing order notifications. BigPictureStyle, MessagingStyle, InboxStyle are templates for expanded notifications. MessagingStyle with Person and avatars is the best choice for chats.

How to Track Delivery and Conversion of Push Notifications?

Sending a notification is half the work. It's important to know: was it delivered, opened, and did it lead to a target action.

FCM returns a MessageId on send, but does not guarantee a delivery callback — by design. For open tracking, custom logic is needed: on notification tap in onMessageReceived or via getInitialNotification() / onNotificationOpenedApp (OneSignal SDK), send an event to analytics with notification_id.

OneSignal provides built-in delivery and CTR analytics. For more detailed analysis — integrate with Amplitude or Mixpanel via webhook on open events. The budget for such a dashboard varies depending on event volume.

How We Implement Push Notifications: Typical Process

1. Audit current implementation — check token storage, update handling, notification types.
2. Design architecture — choose transport (FCM + APNs), segmentation layer (OneSignal/Braze/custom), personalization method.
3. Implementation — write registration code, inbound handling, rich push, deep linking.
4. Testing — send test campaigns, verify delivery on different devices, simulators, regions.
5. Monitoring and analytics — set up dashboard, open and conversion events.
6. Documentation and training — hand over operational materials to the team.

Typical stack: FCM + APNs at transport level, OneSignal or Firebase Notifications Composer for segmentation, custom backend for personalized event-based notifications. For large apps with >1M users, OneSignal has pricing limits — then we use Braze or a custom implementation on AWS SNS.

Timelines depend on complexity: basic FCM+APNs integration with transactional notifications — 1–2 weeks. A full system with segmentation, rich push, analytics, and A/B testing — 4–8 weeks. Order an audit of your current push infrastructure or get a consultation on implementing push notifications in your mobile app — we will contact you within a day and provide an accurate estimate.