Understanding the SDL and cross-cutting concerns for interviews.

— Software Development Lifecycle

Understanding the software development lifecycle of your product is one of the most essential things you should know. It reflects how deeply you understand your product end-to-end. Many engineers focus only on the code they write and miss the bigger picture.

Key Stages to Think About

When SDL questions come up in an interview, walk through each stage:

Stage	What You Need
Plan	Requirements documents, designs, specifications
Code	IDE, programming language, platform, collaborative code repository (e.g., Git)
Build	Build infrastructure — CI systems, artifact registries
Deploy	Deployment pipeline, infrastructure-as-code, release strategy
Run	Cloud or on-prem infrastructure to host services
Monitor	Observability — monitoring, logging, alerting
Dependencies	Third-party libraries, external services, SLAs

Cross-Cutting Concerns

For every stage above, consider these four dimensions:

• Security — Secure everything: code, dependencies, pipelines, infrastructure
• Maintainability — Can the team evolve this over time without pain?
• Scale — Will it handle 10x or 100x growth?
• Reliability — What happens when something fails?