HeadSpin Proposes Speed Optimizations as Cruising Altitude for Delta Air Lines


Overview and Methodology For Our Analysis




iPhone 7 / Verizon / Mountain View

Samsung Galaxy S8 / AT&T / New York

Products Used:

HeadSpin Connected Intelligence Platform


  • Review POST calls to endpoints for flight load page
  • Optimize connection reuse on iOS
  • Review of slow servers
  • HeadSpin analyzed the latest version of the Delta App on an iPhone 7 located in Mountain View on Verizon, and a Galaxy S8 located in New York on AT&T.
  • NO SDK, code change or instrumentation was needed to run the remote performance sessions.
  • HeadSpin’s AI engine sifted through network traffic, client-side metrics, and videos of the test execution to find areas of poor user experience and performance bottlenecks.
  • Recommendations were provided for every issue that was surfaced.

User Reviews

HeadSpin looked at Fly Delta’s reviews in the App Store and found many users were struggling with performance issues and functional errors.

Fly Delta’s ratings is currently 4.8/5 on the App Store and 3.2/5 on the Play Store.


Insights and Recommendations

HeadSpin’s proprietary AI technology analyzes and prioritizes the core issues impacting critical user journeys. Using computer vision techniques to quantify blank screens, time to interact, loading time, loading or buffering animations, and content quality, our AI models can automatically diagnose server-side issues whether they arise from infrastructure deployment issues, poor performance, or API errors. For a custom analysis of your app, request a Performance Insight report from HeadSpin. 

HeadSpin Performance Session for iPhone 7 (link)

Launch Time

The Fly Delta iOS app took 4.44 seconds to launch.

Loading Animation — Flight Load Time

It took 6 seconds for the selected flight to load. The top reasons of the slowdown were POST calls to these endpoints: Endpoint A and Endpoint B.

The calls took 1.72 and 1.93 seconds, respectively.


HEADSPIN RECOMMENDATION: Figure out why these hosts are so slow. It’s likely that they are performing a lot of server-side work before giving a response to the app. Try to reduce this if possible.

Connection Reuse

There were 11 instances of the Delta app creating new connections with Delta APIs instead of reusing existing ones.


HEADSPIN RECOMMENDATION: Consider organizing your connections into a few large buckets, versus many small buckets. Since every connection to your server keeps the device radio on, it’s crucial to minimize the connections that occur to preserve the battery consumption and cellular data used.

HeadSpin Performance Session for Samsung Galaxy S8 (link)

Launch Time

The launch time for the Delta Android app was 4.60 seconds.

Slower Server

These calls to the host all took over 500 ms before receiving a response. They took 2.83 seconds, 1.6 seconds, and 1.96 seconds, respectively. Clicking on the calls provides more detail on the request/response. They corresponded with the user searching for flights, loading a seat map, and loading the flight itself.

The endpoints are listed in order: Endpoint 1 (POST), Endpoint 2 (GET), Endpoint 3 (POST).

HEADSPIN RECOMMENDATION: Look into how much work these servers are performing before fulfilling these requests.

How to Work With HeadSpin

HeadSpin Powers Flawless Mobile App Performance

HeadSpin’s state-of-the-art Digital Experience Intelligence Platform™ will empower your engineering teams to:

  • Execute automation tests on real carrier-enabled devices worldwide
  • Discover performance bottlenecks
  • Collect and visualize your performance data
  • Seamlessly integrate with your CI/CD workflow
  • Monitor every critical user flow of your mobile experience
  • Pinpoint issues that cause performance regressions and impact user experience earlier in your development cycle
Overarching Areas of Opportunities

  • Launch new features confidently by monitoring and analyzing root causes of performance issues throughout the development life cycle
  • Drive new user installs and user engagement with optimized performance
  • Forge user trust and safety, accelerating consumer services for critical user paths across your apps and website
  • Benchmark KPIs for mobile performance to understand how your user experience for your mobile app and website compares to your peers in the same industry
  • Support localized testing across thousands of devices and 70+ countries around the world, on real devices under real-world conditions
Expert Holistic Consultation and Strategy 

HeadSpin has the product and solutions expertise to help you perfect the digital experience for your customers! Our team hails from digital pioneers, such as Google and Facebook, and has already delivered enhanced mobile-centric experiences for a diverse set of Fortune 1000 clients. HeadSpin’s strategic insights can help you:

  • Drive new user acquisition, user engagement, and feature adoption
  • Deploy app security measures on iOS and Android
  • Build consistent performance standards and experiences across all your mobile apps and websites 

... insight from HeadSpin helps us prioritize issues so we could deliver a better user experience.

Maria Zhang, CTO, Tinder