XP teams take every iteration commitment seriously by delivering working software. Continuous Delivery of working product increments and early releasing gives concrete feedback about the state of the system at any time and also increases customer satisfaction.

1. The Journey to
Continuous
Delivery
2 Dec. 2020

2. Presented By &
Introduction
It's an initiative for gathering people
interested in Agile, eXtreme
Programming (aka: XP), Scrum,
Coding, etc.
The Idea of XP Days was found at
November 2019 and since that we
have conducted lots of knowledge
sharing meetups and webinars.
Agile Arena is an Agile Consulting and Training company. We
specialize in agile adoption and transformation for companies
and teams through:
• Designing their agile adoption programs
• Executing our programs and guiding the team through their
journey to sustainable agility .
• We also provide training for teams and individuals to help
them coping with the agility trend in the market.

3. This Webinar
is Held By:
Hesham Amin
Principal Developer
Class Ltd.

4. Presented By &
AGENDA
 Challenges of building software.
 Why is software delivery painful. While it shouldn't
 Agile as a continuous experimentation process
 Continuous delivery and feedback loops
 Principals of Continuous delivery
 Implementation of Continuous delivery
 Impact on software architecture
 Impact on teams
 Discussion

5. Presented By &
Challenges of Software
Development

6. Presented By &
Uncertainty

7. Presented By &
Uncertainty
 “Software is easy to make, except when you want it to do something new. And then, of
course, there is a corollary: The only software that's worth making is software that does
something new.” Scott Rosenberg, Dreaming in Code
 A startup is a human institution designed to create a new product or service
under conditions of extreme uncertainty.” Eric Ries
 Unlike when building a house, when it comes to software it's almost impossible to know
what you want. And even if you did know, it would be impossible to know how long each
part would take to do. Patrick Gleeson, Working with Coders: A Guide to Software Development for the
Perplexed Non-Techie

8. Presented By &
Uncertainty
Continuous Delivery
End Uncertainty Means Uncertainty

9. Presented By &
Mindset change
Experimentation!

10. Presented By &
The scientific method
The scientific method
Hypothesis
Design an experiment
Carry on the experiment
Evaluat
e

11. Presented By &
Fast Feedback

12. Presented By &
Delayed delivery of value
Tim
e
Valu
e
R1
R2
R3
R4
Lost
value

13. Presented By &
Execution Challenges
 Humans make mistakes!
 Deployment “drama”
 Long Cycle time
 Not enough experimentation
 Lack of innovation
 Non value-adding activities

14. Presented By &
What is Continuous Delivery
The ability to get changes of all types into
production, or into the hands of users, safely
and quickly in a sustainable way.

15. Presented By &
Agile manifesto
 Working software over comprehensive documentation
 Our highest priority is to satisfy the customer through early and continuous delivery of valuable software.
 Deliver working software frequently, from a couple of weeks to a couple of months, with a preference to the
shorter timescale.
 Working software is the primary measure of progress.

16. Presented By &
How quick?
 Mean time between deployments:
 11.6 Seconds
 Max. deployments in a single hour:
 1079
 Mean number of hosts simultaneously
receiving a deployment
 1000

 30 Deployments per day
 200+ People
 10000 deployments in 2011

17. Presented By &
Continuous Delivery is a...
 Holistic approach to SW development
 The whole value chain
 Shortest path from business idea to customer value

18. Presented By &
Feedback cycles
Pairing
TDD
Continuous
Integration
Production
monitoring

19. Presented By &
Principles of Continuous Delivery
 Build quality in.
 Work in small batches
 Computers perform repetitive tasks, people
solve problems
 Relentlessly pursue continuous improvement
 Everyone is responsible

20. Presented By &
https://puppet.com/resources/report/2020-state-of-devops-report/

21. Presented By &
Implementation of Continuous Delivery
 Repeatable, reliable process for releasing software
 Computers perform repetitive tasks, people solve problems
 Automate almost everything
 Static analysis
 Test
 Infra
 Deployment

22. Presented By &
Implementation of Continuous Delivery
 Keep (Almost) Everything under source control
 Trunk based development
 Trunk is always deployable
 Check in to trunk at least daily
Trunk
Feature
/ Task

23. Presented By &
Implementation of Continuous Delivery
 If it hearts, do it more often
 “If releasing is hard, people will always find a reason not to release.”
 Gereon Hermkes, Scaling Done Right: How to Achieve Business Agility with Scrum@Scale and Make the
Competition Irrelevant
 Everybody is responsible for the release process
 Visibility

24. Presented By &
Process - Deployment pipeline
VCS
TDD
CI Build
+ automated tests
Artifact
repo
Acceptance
testing
(automated)
Component
Performance
Testing
Production
+ APM
System
Performance
Testing
Manual Testing
Staging

25. Presented By &

26. Presented By &
Impact on Architecture
 Quality attributes: meet cross functional requirements
 Availability:
 Rolling deployment
 Stateless when possible
 DB replicas
 Deployability
 Asynchronous architecture
 Caching & invalidation

27. Presented By &
Impact on Architecture
 Don’t break your clients. Including internal clients
 API versions
 Consumer driven contract testing
 Try to avoid orchestrated deployments

28. Presented By &
Impact on Architecture
 Configurations are stored on the environment
 Environment variables
 Parameters / secrets store
 Observability
 Logs
 Metrics
 APM

29. Presented By &
Patterns of Continuous Delivery
 Expand/Contract:
 Add new stuff first then remove old versions:
 New static content
 New API version
 Expanded DB schema
 Then deprecate old ones
 Blue-Green deployments
 Also a great test for DR
 Deployment != Release
 Feature toggles
 Canary releasing:
 Slowly rolling out the change to a small subset of users before rolling it out to the entire
infrastructure and making it available to everybody

30. Presented By &
Team structure
 Narrow focused teams with clear responsibilities
 Features / not layers
 Cross-team collaboration is usually harder
 You build it – you own it/run it.

31. Presented By &
No end
state

32. Presented By &
https://heshamamin.com/
@heshamamin
https://www.linkedin.com/in/heshamaamin/
https://www.facebook.com/HeshamAminSW/
https://www.youtube.com/c/HeshamAmin

33. Presented By &Continuous Delivery
DISCUSSION