Domain-Driven Design

1. Can you describe your experience with Event Storming, and how you’ve applied it in previous projects?

   • Rationale: Event Storming is a common DDD practice. A genuine candidate should be able to describe their role in facilitating or participating in Event Storming sessions, the outcomes, and how it influenced design decisions.

2. How do you typically identify bounded contexts in a large system, and what criteria do you use to define them?

   • Rationale: Identifying and defining bounded contexts is a core part of DDD. This question tests their understanding of DDD’s strategic design, and a real practitioner should be able to explain both the process and criteria for identifying contexts.

3. Can you walk me through a situation where you had to manage the communication between multiple bounded contexts? What patterns or strategies did you use?

   • Rationale: A candidate familiar with DDD should be able to discuss common strategies like Context Mapping, Anti-Corruption Layers, or Shared Kernel. This question tests their ability to handle the complexity of inter-context communication.

4. What role does ubiquitous language play in a DDD project, and can you share a specific example of how you’ve used it to bridge the gap between technical and non-technical stakeholders?

   • Rationale: Ubiquitous language is fundamental in DDD for ensuring clarity and alignment across teams. A solid candidate should be able to explain how they’ve created and maintained this language in collaboration with domain experts.

5. Can you describe a domain model you’ve designed? What challenges did you face, and how did you resolve them?

   • Rationale: This question evaluates whether the candidate can design a meaningful and accurate domain model. They should be able to discuss key concepts like entities, value objects, aggregates, and how they overcame design challenges.

6. How do you ensure that a system’s design stays aligned with the evolving business requirements in a DDD approach?

   • Rationale: DDD is intended to be iterative and adaptable to evolving business needs. A good architect should be able to explain how they keep the model flexible and how continuous collaboration with domain experts shapes the system’s evolution.

7. Have you ever faced a situation where you had to integrate an existing system with a DDD-designed system? How did you handle the legacy system’s design limitations?

   • Rationale: Integrating new DDD designs with legacy systems can be a challenge. A true DDD practitioner would know how to approach this issue, possibly through techniques like Anti-Corruption Layers or translating between old and new models.

8. In your experience, what are the key signs that a system might benefit from a Domain-Driven Design approach?

   • Rationale: This question checks whether the candidate understands when to apply DDD and can recognize complex domains that would benefit from this methodology. It tests their ability to assess projects and make the case for DDD when appropriate.

9. How do you handle conflicts or disagreements in a DDD context between technical team members and domain experts?

   • Rationale: This question assesses the candidate’s experience in facilitating communication between different stakeholders. Effective conflict resolution is key in DDD, especially when discussing domain models or bounded contexts.

10. Can you explain the difference between a value object and an entity? Give me an example of each from your past projects.

    • Rationale: This question tests the candidate’s knowledge of the basic DDD building blocks. A person with real experience will be able to distinguish between entities and value objects, offering concrete examples from their work.

These questions aim to reveal not just the candidate’s theoretical knowledge, but also how they’ve practically applied DDD in real-world scenarios. A genuine practitioner will be able to share specific examples, discuss challenges, and demonstrate their problem-solving skills in the context of DDD.