DO092 – Developing Cloud-Native Applications with Microservices Architectures — Lesson 1: Cloud-Native Principles, Twelve-Factor Practices, and Application Modernization

Learning Objectives

• Interpret the architecture, dependencies, and expected behavior of cloud-native principles, twelve-factor practices, and modernization drivers.
• Apply delivery speed and operability while preserving reviewable technical evidence.
• Recognize and correct the risk where a hidden prerequisite causes the first configuration step to produce an incomplete result.

Detailed Topics

• cloud-native principles: apply the concept to an application architecture team evaluating how to decompose and modernize a traditional enterprise application, record the relevant settings or decisions, and explain the operational consequence.
• twelve-factor practices: apply the concept to an application architecture team evaluating how to decompose and modernize a traditional enterprise application, record the relevant settings or decisions, and explain the operational consequence.
• modernization drivers: apply the concept to an application architecture team evaluating how to decompose and modernize a traditional enterprise application, record the relevant settings or decisions, and explain the operational consequence.
• delivery speed: apply the concept to an application architecture team evaluating how to decompose and modernize a traditional enterprise application, record the relevant settings or decisions, and explain the operational consequence.
• operability: apply the concept to an application architecture team evaluating how to decompose and modernize a traditional enterprise application, record the relevant settings or decisions, and explain the operational consequence.

Instructor Demonstration

The instructor demonstrates cloud-native principles, twelve-factor practices, and application modernization by tracing the relevant architecture, commands, configuration, messages, and evidence. The walkthrough highlights how a hidden prerequisite causes the first configuration step to produce an incomplete result and shows how to isolate the cause without masking dependent issues.

Hands-On Exercise

Build a baseline and capture the initial state for Cloud-Native Principles, Twelve-Factor Practices, and Application Modernization. Add verified outcomes to the microservices suitability assessment, service-boundary map, architecture risks, and modernization roadmap.

1. Confirm the scope, versions, access, dependencies, and success criteria.
2. Perform the workflow while recording commands, settings, output, and platform events.
3. Test one expected case and one controlled exception specific to this lesson.
4. Retest the correction and document ownership, rollback, and follow-up actions.

Scenario Analysis

• Identify which dependency most strongly influences cloud-native principles in the stated scenario.
• Compare two approaches for delivery speed and explain the security, reliability, and support trade-offs.
• Decide what evidence must be retained in the microservices suitability assessment, service-boundary map, architecture risks, and modernization roadmap before operational acceptance.

Troubleshooting Guidance

Begin with the first observable difference from the expected result. Check architecture, access, dependencies, and starting conditions separately, then correlate logs, events, commands, and configuration history. Do not accept the initial assumption that a hidden prerequisite causes the first configuration step to produce an incomplete result; confirm the cause with a reproducible retest.

Validation Checklist

• The required architecture, access, dependencies, and starting conditions were checked and recorded.
• The normal path and a course-specific exception were tested.
• The microservices suitability assessment, service-boundary map, architecture risks, and modernization roadmap links conclusions to commands, configuration, logs, or other objective evidence.
• Corrective actions, rollback steps, ownership, and handover notes are complete.

Lesson Outcome

Learners can apply Cloud-Native Principles, Twelve-Factor Practices, and Application Modernization, explain the observed Red Hat platform behavior, and support the result with a reviewable microservices suitability assessment, service-boundary map, architecture risks, and modernization roadmap.