Legacy to Mobile First

We all dream of that greenfields project, using the latest technologies and targeting modern mobile devices, but most of us live in a world of existing legacy systems that weren't built with mobile in mind. In this presentation, I'll show how REA is tackling mobile development in a sea of legacy systems systems to make "mobile first" a reality. I look at the challenges and rewards of microservice architectures and hypermedia APIs, as well as how that influences client side development for mobile devices. The hardest aspect of building mobile apps is generally not the app itself, but in massaging the backend systems to provide the useful APIs that make developing mobile apps possible. Yesterday's software systems are unable to deliver today's mobile experiences. I present the shift from a monolithic desktop web app, to a system of microservice APIs with multiple mobile clients.

Transcript

1. LEGACY to MOBILE FIRST Stewart Gleadow | REA Group | stew@rea-group.com | @stewgleadow
2. ARCHITECTURE GUIDELINES DEALING WITH LEGACY TECHNICAL CHALLENGES DELIVERY TEAM STRUCTURE 1. 2. 3. 4.
3. ARCHITECTURE GUIDELINES DEALING WITH LEGACY TECHNICAL CHALLENGES DELIVERY TEAM STRUCTURE 1. 2. 3. 4.
4. OUR IDEAL ARCHITECTURE
5. Easy to adapt, quick to extend Deployed in the cloud OUR IDEAL ARCHITECTURE
6. SUGGEST small SERVICES LISTINGS USERS
7. LISTINGS USERS SUGGEST {…} {…} {…} API DRIVEN
8. MOBILE API simple CLIENTS
9. LISTINGS USERS SUGGEST MOBILE API
10. THE RULES ARE MORE WHAT YOU’D call GUIDELINES
11. ARCHITECTURE GUIDELINES DEALING WITH LEGACY TECHNICAL CHALLENGES DELIVERY TEAM STRUCTURE 1. 2. 3. 4.
12. LEGACY JAVA
13. LEGACY JAVA
14. LEGACY JAVA API
15. LEGACY JAVA API
16. LEGACY JAVA API
17. IT’S DIFFICULT TO evolve and maintain MONOLITHIC SYSTEMS
18. LEGACY JAVA residential LEGACY JAVA commercial
19. LEGACY JAVA residential LEGACY JAVA commercial API API
20. LEGACY JAVA API
21. LEGACY JAVA SEARCH API LISTINGS
22. LEGACY JAVA SEARCH API USERS LISTINGS
23. LEGACY JAVA SEARCH API LISTINGS USERS
24. LEGACY JAVA SEARCH API LISTINGS USERS
25. _links : { autosuggest : { href : “https://autosuggest.realestate.com.au/suburbs{/address}”, templated : true }, search : { href : “https://listings.realestate.com.au/listings{?query}”, templated : true }, login : { href : “https://users.realestate.com.au/users”, templated : false } } JSON endpoint configuration
26. Static site in an S3 bucket
27. Scala API Java API Ruby API
28. Javascript UI library
29. ARCHITECTURE GUIDELINES DEALING WITH LEGACY TECHNICAL CHALLENGES DELIVERY TEAM STRUCTURE 1. 2. 3. 4.
30. LEGACY JAVA SEARCH API USERS LISTINGS (artists impression)
31. LEGACY JAVA SEARCH API USERS LISTINGS (artists impression)
32. LEGACY JAVA SEARCH API USERS SUGGEST SAVED LISTINGS (artists impression)
33. LEGACY JAVA SEARCH API USERS SUGGEST SAVED LISTINGS
34. LEGACY JAVA SEARCH API USERS SUGGEST SAVED LISTINGS
35. © Igor Motov, Spiderweb, http://www.flickr.com/photos/71411059@N00/6171222658/ (modified). Creative Commons 4.0 Traded a complicated monolith for a complex web of interacting services
36. {…} LISTINGS USERS {…}
37. {…} LISTINGS USERS Pact: consumer driven contact testing {…} github.com/realestate-com-au/pact github.com/dius/pact-jvm
38. my_service_provider. given("something exists"). upon_receiving("a request for something”). with(method: :get, path: '/something'). will_respond_with( status: 200, headers: {'Content-Type' => 'application/json'}, body: {name: 'A small something'} ) ! subject.get_something
39. FREEDOM vs CONSISTENCY
40. Freedom within a service but consistency in deployment and interactions
41. COOKIE-CUTTER APPROACH TO NEW SERVICES
42. LISTINGS USERS SUGGEST LISTINGS USERS SUGGEST PROD STAGING
43. LISTINGS USERS SUGGEST LISTINGS USERS SUGGEST PROD STAGING
44. USERS LISTINGS USERS SUGGEST (new version)
45. USERS LISTINGS USERS SUGGEST (new version)
46. USERS LISTINGS USERS SUGGEST (new version)
47. _links : { autosuggest : { href : “https://autosuggest.realestate.com.au/suburbs{/address}”, templated : true }, search : { href : “https://listings.realestate.com.au/listings{?query}”, templated : true }, login : { href : “https://users.realestate.com.au/users”, templated : false } } Use entry points to test different environments
48. _links : { autosuggest : { href : “https://autosuggest.realestate.com.au/suburbs{/address}”, templated : true }, search : { href : “https://listings.realestate.com.au/listings{?query}”, templated : true }, login : { href : “https://users.realestate.com.au/users”, templated : false } } Use entry points to test different environments
49. _links : { autosuggest : { href : “https://autosuggest.realestate.com.au/suburbs{/address}”, templated : true }, search : { href : “https://listings.realestate.com.au/listings{?query}”, templated : true }, login : { href : “https://users.realestate.com.au/users”, templated : false } } Use entry points to test different environments “https://users.test.realestate.com.au/users”
50. ARCHITECTURE GUIDELINES DEALING WITH LEGACY TECHNICAL CHALLENGES DELIVERY TEAM STRUCTURE 1. 2. 3. 4.
51. ruby JAVA iOS
52. ruby JAVA iOS “mobile team”
53. ruby JAVA iOS “mobile team”
54. ruby JAVA iOS “mobile team”
55. ruby JAVA iOS Cross-functional squads
56. Mobile team? Treat the apps as a product http://en.wikipedia.org/wiki/IPhone_5S End-to-end delivery of an app experience
57. ARCHITECTURE GUIDELINES DEALING WITH LEGACY TECHNICAL CHALLENGES DELIVERY TEAM STRUCTURE 1. 2. 3. 4.
58. COMPLEX SOFTWARE SYSTEMS ARE still hard
59. http://en.wikipedia.org/wiki/Lego SMALL SERVICES SIMPLE CLIENTS POWERFUL APIs
60. THANKS
61. THANKS
62. STEWART GLEADOW stewgleadow.com/talks @stewgleadow stew@rea-group.com REA Group / realestate.com.au Talks: Twitter: Email:
64. REFERENCES • Martin Fowler, Microservices: http://martinfowler.com/articles/microservices.html • Sam Newman, Demistifying Conways Law: http://www.thoughtworks.com/insights/blog/demystifying-conways-law • Michael Feathers, Microservices Until Macro Complexity: https://michaelfeathers.silvrback.com/microservices-until-macro-complexity • Anthony Green, What Is A Microservice And Why Does It Matter: http://www.brunton-spall.co.uk/post/2014/05/21/what-is-a-microservice-and-why-does-it-matter • Richard Clayton, Failing At Microservices: https://rclayton.silvrback.com/failing-at-microservices • Fred George, Microservices Architecture: http://yow.eventer.com/yow-2012-1012/micro-services-architecture-by-fred-george-1286 • Todd Hoff, Microservices Not A Free Lunch: http://highscalability.com/blog/2014/4/8/microservices-not-a-free-lunch.html • Martin Fowler, Strangler Application: http://martinfowler.com/bliki/StranglerApplication.html • Mike Kelly, HAL JSON: http://stateless.co/hal_specification.html • Brandon Byars, Enterprise REST: http://martinfowler.com/articles/enterpriseREST.html • Stewart Gleadow, No App Is An Island: https://speakerdeck.com/sgleadow/no-app-is-an-island • Ronald Holshausen, Testing Interactions With Web Services Without Integration Tests In Ruby: http://techblog.realestate.com.au/testing-interactions-with-web-services-without- integration-tests-in-ruby/ • Ian Robinson, Consumer Driven Contracts: http://martinfowler.com/articles/consumerDrivenContracts.html • Beth Skurrie, Pact Github Repository: https://github.com/realestate-com-au/pact • Travis Dixon, Pact JVM Github Repository: https://github.com/DiUS/pact-jvm • Ronald Holshausen, Simlifying Micro-Service Testing With Pacts: http://dius.com.au/2014/05/19/simplifying-micro-service-testing-with-pacts/ • Henrik Kniberg & Anders Ivarsson, Scaling Agile @ Spotify: https://dl.dropboxusercontent.com/u/1018963/Articles/SpotifyScaling.pdf • Sam Newman, Practical Microservices: http://www.slideshare.net/spnewman/practical-microservices-yow-2013