CI/CD Refresher for System Design
HOME | System Design Resource List
Don’t forget to get your copy of Designing Data Intensive Applications, the single most important book to read for system design interview prep!
Check out ByteByteGo’s popular System Design Interview Course
When preparing for system design interviews, understanding deployment strategies is as critical as designing scalable databases or robust APIs. Concepts like canary releases, build environments, blast radius, and blue-green deployments are foundational for designing safe, reliable software delivery pipelines. This article breaks these down in an interview-ready format — technical, yet easy to digest.
What Is a Canary Release?
Definition
A canary release is a software deployment strategy that slowly rolls out new features to a small subset of users before releasing to the entire user base.
Why It’s Important
- Minimizes the impact of bugs or performance issues.
- Helps gather real-world metrics and feedback before full deployment.
- Enables progressive delivery with rollback safety.
Implementation in Practice
- Use feature flags to enable/disable the new version.
- Monitor logs, error rates, and user behavior.
- Automatically promote or roll back based on thresholds.
Understanding Build Environments
Definition
Build environments are isolated stages in the CI/CD pipeline where code is compiled, tested, and validated before deployment.
Common Types
- Dev: For rapid iteration and initial developer testing.
- QA/Staging: Mimics production to test integrations and performance.
- Prod: Live environment where end-users interact with the application.
Key Benefits
- Prevents faulty code from reaching production.
- Isolates bugs and regressions early.
- Helps simulate real-world conditions before release.
If you are interviewing, consider buying our number#1 course for Java Multithreading Interviews.
Blast Radius
Definition
The blast radius is the scope or magnitude of the impact a system failure can cause.
Importance in Deployment
- Smaller blast radius = reduced risk.
- Critical in high-availability and microservices architectures.
- Influences rollback strategies and redundancy planning.
Ways to Reduce Blast Radius
- Deploy to isolated regions or availability zones.
- Use canaries and gradual rollouts.
- Isolate services using containers or Kubernetes pods.
Blue-Green Deployments
Definition
Blue-green deployment is a technique where two identical production environments — blue (current) and green (new) — are used to reduce downtime during release.
How It Works
- Deploy the new version to the green environment.
- Run tests and validations.
- Route traffic from blue to green.
- Rollback instantly by switching traffic back to blue if needed.
Pros
- Zero-downtime deployments.
- Fast rollback capability.
- Fully tested releases before user exposure.
Your Comprehensive Interview Kit for Big Tech Jobs
0. Grokking the Machine Learning Interview
This course helps you build that skill, and goes over some of the most popularly asked interview problems at big tech companies.
1. Grokking the System Design Interview
Learn how to prepare for system design interviews and practice common system design interview questions.
2. Grokking Dynamic Programming Patterns for Coding Interviews
Faster preparation for coding interviews.
3. Grokking the Advanced System Design Interview
Learn system design through architectural review of real systems.
4. Grokking the Coding Interview: Patterns for Coding Questions
Faster preparation for coding interviews.
5. Grokking the Object Oriented Design Interview
Learn how to prepare for object oriented design interviews and practice common object oriented design interview questions
6. Machine Learning System Design
