Mobile Session Replay: built for real observability

Mobile engineers are flying blind

If you work on the backend, you've got it good. You have distributed tracing, structured logs, and granular metrics that can pinpoint a failure in seconds. On mobile, we've historically been happy just to get a stack trace. While crashes are important, most apps are 99% crash free. Crashes are just the tip of the iceberg. The issues that actually impact your user experience are things like: screen freezes, pages that take way too long to load, and random freezes. These issues have historically been gaps where crash reporters haven't been able to solve. This ushered in a new set of tools: session replay tools. They sound good on the surface, but they are just ported from web logic and they don't translate to the complexities of mobile apps. At bitdrift, we decided it was time to rethink Session Replay from the ground up.

Screen recordings are not observability

The industry standard for "replay" is basically just video capture or UI snapshots. Seeing what the user saw is fine for a UX researcher, but it's rarely enough for an engineer to find a root cause.

• The Sampling Trap: Video is heavy, expensive, and can accidentally catch PII. Most teams sample so aggressively that the long tail issues, the ones affecting 0.1% of your users, never even make it to your dashboard.
• High Cost, Low Confidence: Don't forget, shipping massive amounts of video data is a tax on your user's battery and data plan. It's a high friction approach that yields low fidelity results.
• Surface Level Data: A video may show a button not responding, but it won't tell you if the main thread was blocked by a heavy database write or if a network call was stuck in a queue.

Most tools will hopefully show what users saw, but often it stops there. They don't have a good way to show what else was going on under the hood. We built bitdrift's Session Replay to show what actually happened inside the app.

Why we built our Session Replay this way

Mobile apps are dynamic systems, not static UI flows. They run on millions of different devices, operating systems, and less-than-great network connections. To debug properly, you need visibility into the machine, not just the interface. That's why we built our Session Replay around two core beliefs:

1. Execution visibility over video: Engineers need to see processes, thread activity, and resource contention.
2. Runtime decisions: Observability should be dynamic. You shouldn't have to guess what to log three weeks before your next App Store release. Unless you're into that kind of thing.

What makes bitdrift Session Replay different?

We don't ship videos. This eliminates the overhead of capturing, storing, and sending of that data. Instead, bitdrift Session Replay is driven by on-device telemetry. By reconstructing the user journey using actual execution data, we can provide a 3D rendering of app behavior. Did you catch that? It's 3D and you can see every layer of your app. This isn't just a playback, it's a visualization of the app's internal state. We monitor:

• App Processes: Lifecycle state changes in real time.
• Thread Activity: Pinpoint exactly when and why the UI thread is fighting for resources.
• Network Context: See the timing and status of every request as it relates to the UI.
• Performance Bottlenecks: Identify the exact frame where the drop happened and what caused it.

The combination of this data coupled with 3D renders gives you full fidelity context without massive data overhead. Say that three times fast.

What this means for your workflow

bitdrift's approach to Session Replay shifts the mobile debugging experience from "best guesses" to "knowing."

• Solve the Unreproducible: Mobile engineers can finally diagnose the issues that only happen on specific OS versions or devices that they've never heard of.
• Stop the Release Cycle: Because bitdrift captures data dynamically, you find a root cause without having to add more logs, wait for a new build, and release just to hopefully catch the issue.
• See the Why: Just to drive this point home, you'll actually understand why a screen feels slow by seeing the app memory usage in real time and background processes competing for the CPU during that specific interaction.

Real world scenarios

• The Slow Checkout: We've all been there. Customers will report that a screen feels slow, or even worse, a laggy "Place Order" button. Instead of just seeing them tap repeatedly, you see a background analytics sync blocking the main thread at the exact moment of the interaction. Can you even imagine?
• The Battery Drain Complaint: What if you get reports of a new app update draining users batteries? Good luck catching that with just a video. bitdrift will help uncover a runaway loop or a resource that only triggers under specific conditions, causing a massive battery spike.
• The Minor UI Regression: Understand why a small tweak to a navigation flow caused users to get stuck in a loop, even when the app technically didn't crash or fail.

Log everything, send only what matters

bitdrift isn't a one trick pony. Session Replay is just one part of the bitdrift ecosystem. It's powered by our core methodology: Log everything locally, send only what matters. Our on device logging and dynamic control means that you send session and replay data only when you need it. You get the benefit of a local debug session with the scale of production, without the video recording data tax.

Make mobile debuggable, not a best guesstimate

Mobile engineers, now is your time to shine. You deserve backend grade observability. The user experience is no longer just a black box. bitdrift Session Replay, coupled with mobile telemetry, was built to help explain behavior, not just record it.

• Learn more: bitdrift.io/feature/replay
• The tech: Read about how we implemented Session Replay for Jetpack Compose on Android.