This document discusses some of the challenges with microservices architectures. It begins by describing how microservices aim to achieve isolation by separating systems into independent components. However, it notes that this can lead to new issues around coordination and dependencies between services. The document then examines various approaches and patterns for managing inter-service communication, including event buses, API gateways, and CQRS. It ultimately argues that microservices require a holistic, platform-based approach to address cross-cutting concerns like deployment, testing, and observability across independent services.

1. Microservices: The Dark Side
Prem Chandrasekaran Shelley Trout
With: Moderated by:
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4. About Prem Chandrasekaran
Premanand (Prem) Chandrasekaran is a distinguished engineer and group lead for platform services at Barclays
US. Previously, he was a principal consultant at ThoughtWorks. Over the last two decades, Prem has worked on a
variety of software projects, spanning varied functional and technical domains. He’s passionate about the
application of iterative methods to deliver software that enriches the lives of its end users and its maintainers
alike. His interests also include technical architecture, refactoring, and performance tuning, among others. When
not fiddling with his trusty laptop, he spends time with his son doing Lego Mindstorms and playing video games.
He’s also obsessed with playing and analyzing the nuances of the game of cricket.
About Shelley Trout
Shelley leads webinar production at Aggregage, the publisher of more than 40 B2B publications. She has
successfully produced hundreds of webinars featuring thought leaders, across a range of industries, and delivering
diverse and rich content and tens of thousands of targeted leads to webinar sponsors. Shelley is a published author
and writer, who previously worked as a director and producer on the West End while studying Theater in London.
After moving to the U.S., she majored in Anthropology & Archaeology at UC Berkeley, worked at the Center of Digital
Archaeology, and wrote her thesis on digital representations of people and their stories.
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5. About Me
premanandc
Working with containers since 1997 ;-)

6. ACT I: SETUP

7. Recognize Me?

8. Unsinkable!
RMS Titanic

9. Wrecked!

10. HMHS Britannic
Also... Wrecked!

11. SO… WHAT HAPPENED?

13. SO… WHAT’S THE POINT?

14. ISOLATION == VALUE!

15. ACT II: CONFRONTATION

16. The Mighty Monolith

17. Independent Service Extracted

18. Service Extraction - Contd.

19. Service Extraction - Contd.

20. Service Extraction - Contd.

21. Inter-Service Dependencies

22. Enter Event Bus
EVENT BUS

23. UI Orchestration
EVENT BUS
UI UI UI

24. Enter API Gateway
EVENT BUS
API GATEWAY
UI UI UI

25. What About Integration?
EVENT BUS
API GATEWAY
UI UI UI
G
A
T
E
W
A
Y
Legacy
Systems
G
A
T
E
W
A
Y
Partner
Systems
GATEWAY
Vendor Systems

26. CQRS - Did you mean Cars?
EVENT BUS
API GATEWAY
UI UI UI
Command Query

27. Free Lunch!!
Finally… We Have Arrived!!?!
EVENT BUS
API GATEWAY
UI UI UI
G
A
T
E
W
A
Y
Legacy
Systems
G
A
T
E
W
A
Y
Partner
Systems
GATEWAY
Vendor Systems

28. ACT III: RESOLUTION…?

29. 1. HOW DID WE END UP HERE…?
What problem are we solving again…?

30. Entities
Value Objects
Domain Events
Aggregates
Repositories
Domain Services
Factories
Orchestration Services
UI
1. DDD… NOT (ONLY) A TECH PRACTICE…!
Why can’t the architects and domain experts solve it…?

31. Service
GATEWAY
2. WHAT ARE WE BUILDING?
What do you mean we can’t just deploy to the cloud?
Service Service Service ServiceService
UI UIUI
Business Capabilities

32. Why can’t we just deploy to the cloud?
2. WHAT SHOULD WE BE BUILDING…?
Business Capabilities

33. Business Capabilities
Cross-Functional Capabilities
Infrastructure Capabilities
Engineering
Practices
App Config Secrets AuthN/Z
Log Agg. Monitoring Alerting
App Load
Balancer
Service
Discovery
Dashboards
API
Management
APM …
Messaging Database Cache
CPU Memory
Cert
Authority
DNS
Network
IT
Automation
Block Storage
Object
Storage …
Branching Versioning
Static
Analysis
Code
Reviews
Continuous
Integration
Automated
Testing
Automated
Deployments
Dependency
Management
Infrastructure
as Code
Chaos
Engineering
Evolutionary
Architecture …
Why can’t we just deploy to the cloud?
2. NON-BUSINESS CAPABILITIES?
Delivery
Capabilities
Source
Control
Build Server
Binary
Artifact Repo
Project
Tracking
Team Coll.
Wiki
Bug Tracking
Compliance
Persistent
Group Chat
Config
Management
Application
Templates
Developer
Workstations …

34. PROJECT PRODUCT PLATFORM
3. HOW SHOULD WE BUILD…?
You mean I shouldn’t reinvent the wheel…?

35. 3. PLATFORM THINKING
You mean I shouldn’t reinvent the wheel…?
Discoverable Reusable Self Service

36. 4. API OBSESSION
I won’t ReST until…
Glory of
Level 0: The Swamp of POX
Level 1: Resources
Level 2: HTTP Verbs
Level 3: Hypermedia
ReST
https://martinfowler.com/articles/richardsonMaturityModel.html
CQRS

37. Domain-Driven Design?
5. ENCAPSULATION
Should I hand you my wallet…?
Data Transfer Object
Driven Design :’-(

38. 6. CQRS
Can we just stick to talking about cars instead…?
EVENT BUS
API GATEWAY
UI UI UI
QueryCommand

39. 7. EVENTUAL CONSISTENCY
Partition
Tolerance
AvailabilityConsistency CA
CP AP
Please hold… Your call is important to us…

40. 8. API COORDINATION
The never-ending saga…

41. 8. ORCHESTRATION OR CHOREOGRAPHY?
The never-ending saga…
Graphics credit: https://www.freepik.com

42. 9. INDEPENDENT DEPLOYMENT PIPELINES
Version
Control
Build Unit Test Package
Expensive
Tests
Deploy To
Production
Measure &
Validate
Feedback
Is your future in your own hands…?

43. Version
Control
Build Unit Test Package
Expensive
Tests
Deploy To
Production
Measure &
Validate
Fe
Version
Control
Build Unit Test Package
Expensive
Tests
Deploy To
Production
Measure &
Validate
Fe
Version
Control
Build Unit Test Package
Expensive
Tests
Deploy To
Production
Measure &
Validate
Fe
Version
Control
Build Unit Test Package
Expensive
Tests
Deploy To
Production
Measure &
Validate
Fe
Version
Control
Build Unit Test Package
Expensive
Tests
Deploy To
Production
Measure &
Validate
Fe
Version
Control
Build Unit Test Package
Expensive
Tests
Deploy To
Production
Measure &
Validate
Fe
Version
Control
Build Unit Test Package
Expensive
Tests
Deploy To
Production
Measure &
Validate
Fe
Version
Control
Build Unit Test Package
Expensive
Tests
Deploy To
Production
Measure &
Validate
Fe
9. INDEPENDENT DEPLOYMENT PIPELINES
Is your future in your own hands…?

44. 10. TESTING PRACTICE
Unit
Service
UI
Manual Checks
https://www.mountaingoatsoftware.com/blog/the-forgotten-layer-of-the-test-automation-pyramid
I don’t always test my code… but when I do…

45. Unit
Service
UI
Manual Checks
ICE-CREAM CONETEST PYRAMID
Unit
Service
UI
Manual Checks

46. TEST PYRAMID
Unit
Service
UI
Manual Checks
ENHANCED PYRAMID
Unit
Service
UI
Contract
Manual Checks

47. PRODUCER
CONSUMER
CONSUMER
11. CONSUMER-DRIVEN CONTRACT TESTING
The customer is always right in control…

48. 12. VERSIONING
v1.0.0 v1.0.1 v1.1.0 v2.0.0
To do or not to do… that… is the question

49. 13. OBSERVABILITY
By Andrew Z. Colvin - Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=13251597
I can still see you…

50. SO… WHAT ELSE?
Hiring and Training Staff
Event Ordering
Environment Provisioning
Database Migrations
Test Data Management
Blue Green Deployments
Rolling Deployments
Feature TogglesService Discovery
12-Factor Applications
Secrets Management
API Management
Configuration Management
Information Security
Concurrency Control
DevOps as a Philosophy
Trunk-based Development
Code Reviews
Outcome Oriented Teams
Distributed Teams
Client-side Load Balancing
API Documentation
SecurityInfrastructure as Code

51. Otherwise…

52. The Modern Tech Stack
Webinar Series
Q&A
Shelley Trout
With: Moderated by:
Principal, ThoughtWorks
Linkedin page: /in/premanandc/
Twitter ID: @thoughtworks
Website: thoughtworks.com
Prem Chandrasekaran
Managing Editor, Aggregage
Linkedin page: /in/shelleytrout/
Twitter ID: @ctouniverse
Email: shelley@aggregage.com
Website: ctouniverse.com
https://www.ctouniverse.com/webinar-series/10744/the-modern-tech-stack