Building an in-house mobile app monitoring tool : what it takes and key considerations

As mobile apps become complex and number of users increase, ensuring optimal performance becomes critical. Many companies face a key decision: build a custom internal performance monitoring tool or just subscribe to a SaaS. Building a mobile app performance monitoring tool in-house is a substantial but rewarding challenge. It allows your team full control over the data, customisation options, and direct alignment with business needs. While it's a strategic investment, there are critical steps, components, and challenges you should keep in mind to ensure success.

Here’s what it takes to build your own tool and key things to look out for along the way:

1. Establishing Clear Goals and Metrics

Before you dive into development, it's crucial to define what success looks like for your mobile app’s performance. Ask yourself:

• What specific metrics do you need to monitor? These could include crash rates, user engagement, session lengths, network performance, or memory usage.
• How often should data be collected and analysed? Some metrics require real-time monitoring, while others might need periodic analysis.
• What types of alerts or notifications are necessary? Your team may need immediate notifications when thresholds are crossed, such as when crashes spike after a new release.

Takeaway: Clearly defining your goals upfront will keep your project focused and prevent scope creep during development.

2. Developing the SDK for Data Collection

The core of any mobile performance monitoring tool is the SDK (Software Development Kit) that runs within your app and collects data. Here’s what to focus on:

• Lightweight & Non-Intrusive: The SDK should have minimal impact on app performance. A heavy SDK can skew performance metrics and degrade the user experience.
• Platform-Specific Needs: Whether your app is built for Android, iOS, or both, you'll need to design SDKs that are optimised for each platform, considering their unique environments.
• Custom Metrics: While you can start with basic metrics like crashes, memory leaks, and battery consumption, the SDK should be designed to easily add custom metrics as your monitoring needs evolve.

Takeaway: Ensure the SDK is efficient and flexible so that it evolves alongside your app’s performance needs.

3. Building the Data Pipeline: API & Backend

Once data is collected through the SDK, you need a robust pipeline to transmit, store, and analyse it. This involves creating a backend and API infrastructure to handle the incoming data.

• Efficient Data Transmission: The SDK needs to send data securely and efficiently to your backend without overloading the app's network usage.
• Scalable Storage Solutions: Depending on the volume of data, consider scalable storage options such as cloud databases or distributed storage systems. You’ll need the ability to store, index, and retrieve large datasets efficiently.
• Security and Compliance: Given that performance data might include user information, ensure that your data pipeline follows best practices for security (e.g., encryption, token-based authentication) and complies with regulations like GDPR.

Takeaway: Design your API and backend to handle scale, ensure data security, and keep future growth in mind.

4. Creating the Dashboard for Visualisation

A performance monitoring tool is only as good as the insights it provides. Your dashboard is where the collected data comes to life, helping you track app performance in real-time and analyse trends over time.

• Intuitive Design: Create a dashboard that is easy to navigate, even for non-technical stakeholders. Remember, every engineer who is pushing code to production will be using it.
• Customisable Views: Ensure the dashboard can be tailored to different users. Developers might want to see technical data, while managers may need a high-level overview of app health.
• Alerting and Reporting: Integrate features like automated alerts, so you can get notified of critical issues in real-time, as well as scheduled reporting for long-term performance trends.

Takeaway: A user-friendly, flexible dashboard is crucial for extracting actionable insights from the collected data.

5. Handling Data at Scale

As your app grows, the volume of performance data you collect will expand rapidly. You’ll need to design your tool with scalability in mind to avoid bottlenecks.

• Real-Time Data Processing: Consider implementing real-time processing for critical metrics, such as crash reports, to detect issues as they arise.
• Data Retention Policies: Define how long you’ll store data. While recent data is crucial for real-time monitoring, long-term data may be needed for trend analysis or compliance purposes.
• Scalable Infrastructure: Use cloud-based or distributed systems that can grow with your app’s user base. Scaling vertically or horizontally will ensure that your system can handle peak loads without losing data.

Takeaway: Plan for scalability from day one, so you can maintain performance as your data and user base grow.

6. Maintenance and Continuous Improvement

Building the tool is just the beginning. Continuous monitoring, bug fixing, and feature updates will be an ongoing task.

• Bug Fixes & Enhancements: Expect that the tool itself will need updates and bug fixes, particularly as your app’s architecture evolves or when you introduce new features.
• Performance Tuning: Regularly review how the SDK and backend perform under real-world conditions. You’ll likely need to optimise both to ensure they don’t impact the app’s performance.
• Staying Ahead of Emerging Trends: As mobile platforms evolve, so do performance challenges. Regularly update your tool to handle new issues (e.g., changes in OS versions, device fragmentation, new networking technologies). If you want to adopt Compose / SwiftUI / Flutter / React Native; you need to update your tool first.

Takeaway: Treat your performance monitoring tool as a dynamic product that requires ongoing refinement to stay effective.

7. Challenges to look out for

While building an internal tool offers many advantages, it also comes with its share of challenges. Here’s what to be mindful of:

• Resource Investment: Building such a tool is resource-intensive. Make sure you have the necessary engineering expertise and time commitment, as this is not a one-time project.
• Potential for Scope Creep: With internal tools, there’s always the temptation to keep adding features. Stay disciplined and focus on the core requirements first before expanding.
• Cross-Departmental Coordination: Performance monitoring tools often require input from various teams (e.g., mobile developers, PMs, designers, researchers). Make sure communication is streamlined and all stakeholders are aligned.
• Balancing Speed with Accuracy: Collecting performance data quickly is important, but accuracy is paramount. Be careful not to trade precision for speed, as poor data will lead to misguided optimisations.

Takeaway: Be prepared to manage these challenges, but know that the result will be a powerful tool that enhances your app’s performance and user experience.

Is It Worth the Effort?

Building a mobile app performance monitoring tool internally is a significant endeavour, but it pays off by offering you full control over how your app’s performance is measured and improved. With clear goals, a dedicated team, and the right design considerations, you can create a tool that not only monitors app health but drives long-term success.

I came across few team who have either built such a tool or are thinking of it. Most of them say that it's not being maintained as the priorities have changed. People who are thinking of building it are struggling with putting together a team either by hiring internally or externally. There is a cost of running this team and it always competes with other priority. Make sure to align everyone to a long term outlook.

Remember, the journey won’t be easy, but it will give you a solution that’s perfectly tailored to your needs. You’ve got this! ??

Alternative: Adopt Measure

We are building Measure; an open source tool to monitor mobile app. You can self host it. It captures crashes, ANRs, navigation events, API requests, and much more to create detailed session timelines that helps spot patterns and get to the root cause. Checkout on GitHub and star it for updates- https://github.com/measure-sh/measure