Thoughtworks advice on Enterprise Software and Monoliths

Main Themes

1. Decentralization
2. Really understand your business needs (models)

Highlights

• Bringing about change
• Grassroots with support from exec level
• Really understand the upcoming business needs
• Drawbacks of centralized infrastructure (CD, Stage environments, etc)
• Teams should own their own build pipeline and infrastructure 
• Teams fork their own image of production
• Kafka can become a bottleneck
• Leave control of events to the individual domains/services
• Same with API gateway
• Testing
• Decentralize: do NOT rely on integration tests (they become a bottleneck)
• Use consumer-driven contract based testing instead
• Focus on recovery (MTTR) instead of prevention
• Security
• Need to consider security earlier in the process rather than late rejections
• Can no longer rely on a central security perimeter
• Each microservice - validates and cannot trust
• Monolith
• High entropy
• Start where it matters
• Business needs - What is coming down the pipeline?
• Social code analysis - what changes very often?
• Evolutionary changes, not revolutionary
• What is the smallest unit of change to get us closer to the goal
• Don't leave multiple implementations: old and new 
• Options
• Rewriting selectively is many times the right approach
• Break out what's most important
• Facade with APIs/GraphQL (good start, but..)
• Unfortunately, core functionality is still locked into the monolith
• Data pipeline
• Experimentation
• Important when production costs are high
• Consume first, build next
• Observability (logging/tracing/etc) should be included from the start
• Developers as the primary producers and consumers of Splunk, etc.