The document discusses how Homedepot.com transitioned from a monolithic architecture to microservices between 1996 and 2015, aiming to increase development speed and operational stability. Key strategies included setting clear objectives, implementing continuous integration, defining boundaries, and preparing for future changes while adopting cloud technologies. The result was a significant increase in sales, developer count, and deployment frequency.

1. Evolving toward microservices
How HomeDepot.com made the switch

2. About me
Christopher Grant
Sr Architect HomeDepot.com
cgrant
cgrant

3. Building the monolith

4. 1996

5. 2011
• 2 GB Java Deploy that took an hour
• Locking SCM (Clear Case) with no CI
• 3 Month long release Cycles
• 2-4 hour deploy outages

6. Breaking Down the Monolith

7. Our Objective
• Increase the rate of change
• Increase number developers
• Maintain and enhance operations

8. Agile

9. Domain Spaces

10. Continuous Integration Tooling

11. APIs

12. Feature Throttles

13. Result
2011 2015
Apps 1 30
Sales $1b $5b
Developers 170 300
Deploy frequency 3 month Weekly

14. 2015 began moving to
cloud & micro services
Butwait
Theres more!!

15. Evolving Architectures

16. Iterative Architecture?

17. Changing the wheels while driving?

18. Evolutionary Architecture

19. Start with a vision
• Have a vision
• Understand your objectives
• Choose what matters
• Implement in stages

20. Decompose & Define Boundaries
• Understand business products & domains
• Identify people structures
• Review data models
• Look for the hard things

21. Architect for Change
• Prepare for future changes
• Be proactive not reactive
• Delay until the last responsible moment
• Expect but minimize future rework

22. Implement Safely
• Automate early and often
• Consider in-place and green-field
• Utilize feature switches and traffic throttles
• Encourage separation and independence