1. Mobile Consumer Experience: designing for fast response time OSCON 2013 David Elfi Intel

2. Introduction Working for AppUp since its conception More than 3 years of experience on application store businesses for different devices and areas (Consumers, Enterprise, Developers)

3. Motivation Mobile applications present several challenges related to performance Scope: Data driven applications This talk is based on the experience collected in the development of Tizen Common Store (v0.5)

4. Challenges - UX “3 seconds is the limit. 57% of consumers will abandon after 3 seconds of delay” 1 1. http://www.strangeloopnetworks.com/resources/infographics/web-stress/poster/http://www.strangeloopnetworks.com/resources/infographics/web-stress/poster/ 2. http://www.thestrategyweb.com/neurological-study-bad-websites-causing-web-stresshttp://www.thestrategyweb.com/neurological-study-bad-websites-causing-web-stress “Bad designed websites and slow loading times are causing ‘web stress’ for internet users” 2

5. Challenges - Mobile Mobile Network – Unreliable, High Variability in latency and bandwidth – Switch 3g/Wifi Source: http://blog.davidsingleton.org/mobiletcp/ (2011)http://blog.davidsingleton.org/mobiletcp/

6. Challenges - Mobile Device fragmentation Deployment: no-control over Updates

7. Your current thoughts: I know all of these, so, what is your proposal?

8. Hybrid application: – Beta testing – Make use of platform capabilities: HTML5 – Out of the box caching capabilities – Deals with different devices

9. Prepare Data: Decouple Backend logic from presentation into two layers

10. Presentation Layer Cache and DB syndication Caching & Syndication …… Backend logic 3 rd party services Services requests Load Balancer

11. Comparing Presentation Layer Pros – Adapt the data to be cached according to UX – Services mash ups just for presentation – Horizontal scalability – Specialized teams (Backend vs Presentation + FrontEnd) Cons – More infrastructure to maintain – More pieces to join for a single application

12. Be cache-ful: – Data as close to the device helps response time – Minimizes data transfer

13. Data design: Design and enable strong caching strategy

14. Date Design - Key Task Split data flows into general and user specific – Adapt General Data with user specific at Presentation layer

15. Application details – Skeleton cached – Asynch call for specific info

16. Identify Caching Points Presentation Layer Cache and DB syndication Caching & Syndication User Caching User Caching User Caching CDN with WW Coverage Device Network: Carrier Caching Proxies Cache by period of time Caching Point General Data User Specific Data

17. Results Be cache-ful using Presentation Layer – Immediate response time (warm start) – Cold start: CDN publishing minimizes round trip – Reduce data transfer (almost 50%) Hybrid application – Continuous development – Minimize Testing resources (AB Testing)

18. Network Optimization CDN caching  static and “dynamic” content Minimum number of HTTP requests Optimize CSS/JS files Avoid HTTPS for public data (cost/configuration) – Sign resources in case you want to validate source Zip data transfers (HTTP compression + packages to be installed) HTTP Pipelining

19. Remember! Always check performance on the client

20. Q&A

21. Thanks! david.r.elfi@intel.com @elfoTech