Pipeline & Application Architecture

1. Build a Deployment Pipeline

The first step is to create a single, automated deployment pipeline to production. Human intervention should be limited to approving stage gates where necessary.

Entangled Architecture - Requires Remediation

Common Entangled Practices

• Team Structure: Feature teams focused on cross-cutting deliverables
• Development Process: Long-lived feature branches
• Branching: Team branches with daily integration to trunk
• Testing: Inverted test pyramid common
• Pipeline: Focus on establishing reliable build/deploy automation
• Deploy Cadence / Risk: Extended delivery cadence, high risk

Entangled Improvement Plan

Find architectural boundaries to divide sub-systems between teams, creating product teams. This will realign to a tightly coupled architecture.

Tightly Coupled Architecture - Transitional

Common Tightly Coupled Practices

• Team Structure: Product teams focused on decoupling sub-systems
• Development Process: Continuous integration
• Branching: Trunk-Based Development
• Testing: Developer Driven Testing
• Pipeline: Working towards continuous delivery
• Deploy Cadence / Risk: More frequent deliveries, lower risk

Tightly Coupled Improvement Plan

1. Extract independent domain services with well-defined APIs
2. Consider wrapping infrequently changed, poorly tested components in APIs

Loosely Coupled Architecture - Goal

Common Loosely Coupled Practices

• Team Structure: Product teams maintain independent components
• Development Process: Continuous integration
• Branching: Trunk-Based Development
• Testing: Developer Driven Testing
• Pipeline: One or more independently deployable CD pipelines
• Deploy Cadence / Risk: On-demand or immediate delivery, lowest risk

2. Stabilize the Quality Signal

After establishing a production pipeline, focus on improving the quality signal:

1. Remove flaky tests from the pipeline
2. Identify causes for test instability and take corrective action
3. Bias towards testing enough, but not over-testing
4. Track pipeline duration and set a quality gate for maximum duration

3. Continuous Improvement

Use the Theory of Constraints (TOC) to continuously improve your delivery process:

1. Identify the system constraint
2. Decide how to exploit the constraint
3. Subordinate everything else to the above decisions
4. Elevate the constraint
5. If a constraint is broken, return to step one

Common constraints include:

• Resource Constraints: Limited capacity of people or environments
• Policy Constraints: Policies or practices that impede flow

Further Reading