DevOps / ArgoCD interview questions

How do ArgoCD Sync Waves and Sync Hooks work together to control deployment ordering?

ArgoCD provides two complementary mechanisms for controlling the order of resource application during a sync: Sync Waves control the sequence of resource groups, and Sync Hooks inject one-off Jobs at specific lifecycle phases.

Sync Waves

Every resource can be assigned an integer wave via the annotation argocd.argoproj.io/sync-wave. Resources with lower wave numbers are applied first; ArgoCD waits for all resources in wave N to become healthy before advancing to wave N+1. The default wave is 0. Negative waves are useful for CRDs or Namespaces that must exist before other resources reference them.

metadata:
  annotations:
    argocd.argoproj.io/sync-wave: "-1"  # Namespace first
---
metadata:
  annotations:
    argocd.argoproj.io/sync-wave: "0"   # Default: Deployments, Services
---
metadata:
  annotations:
    argocd.argoproj.io/sync-wave: "1"   # Last: Ingress or smoke-test Job

Sync Hooks

Hooks are Kubernetes resources (usually Jobs) annotated with argocd.argoproj.io/hook. Available hook phases:

Hook Phase	When it runs
PreSync	Before any resources are applied (e.g., database migrations)
Sync	During the sync alongside other resources
PostSync	After all resources are healthy (e.g., smoke tests, notifications)
SyncFail	Only when the sync fails (e.g., rollback alerting job)

Waves and hooks compose naturally: a PreSync hook runs before wave -1, and a PostSync hook runs after the highest wave reaches healthy. Use argocd.argoproj.io/hook-delete-policy to clean up completed hook Jobs automatically.

Take quiz

What does ArgoCD do between sync waves before advancing to the next wave?Waits for all resources in the current wave to become healthy

✓ Well done! ArgoCD health-gates each wave; the next wave only starts when all current wave resources are healthy.

Pauses for a configurable fixed timer between waves

✗ Try again — the gate is resource health status, not a timer.

Rolls back the previous wave before applying the next

✗ Try again — waves advance progressively; there is no automatic rollback between waves.

Which sync hook phase is best suited for running a database migration before application pods are deployed?PostSync

✗ Try again — PostSync runs after all resources are healthy, which is too late for a pre-deploy migration.

PreSync

✓ Well done! PreSync hooks run before any resource is applied, making them ideal for migration Jobs.

SyncFail

✗ Try again — SyncFail only triggers when the sync operation itself fails.

Sync

✗ Try again — the Sync phase runs alongside other resources, not before them.

More Related questions...

What is ArgoCD and what problem does it solve? What is GitOps and how does ArgoCD implement it? What are the core components of ArgoCD? What is an ArgoCD Application and what fields does its manifest require? What are the different application sync statuses in ArgoCD? How do you install ArgoCD on a Kubernetes cluster? What is an ArgoCD Project and how does it differ from a Kubernetes namespace? How does ArgoCD support Helm charts? How does ArgoCD support Kustomize? What is self-healing in ArgoCD and how do you enable it? What is the difference between ArgoCD automated sync and self-healing? How does ArgoCD handle resource pruning and what risks does enabling it carry? What is the ArgoCD App of Apps pattern and when should you use it? How do ArgoCD Sync Waves and Sync Hooks work together to control deployment ordering? What is an ArgoCD ApplicationSet and how does the Git generator work? How does ArgoCD integrate with external secret management tools like Vault or Sealed Secrets? How do you configure ArgoCD RBAC and what are the built-in roles? What is ArgoCD Image Updater and how does it automate container image updates? How does ArgoCD manage multiple clusters and what are the methods for registering them? What are ArgoCD Sync Windows and how do you configure them? How does ArgoCD handle ignoreDifferences and when should you use it? What are ArgoCD resource health checks and how do you write a custom one? How does ArgoCD handle SSO and what identity providers does it support? What is the ArgoCD CLI and what are the most common commands used day-to-day? How does ArgoCD compare to Flux and when would you choose one over the other? What is server-side apply in ArgoCD and why might you enable it? How does ArgoCD handle notifications and what channels does it support? How do you perform a rollback in ArgoCD? What is the ArgoCD repository server caching strategy and how does it affect performance?

Show more question and Answers...

GitLab CI Basics Interview Questions

	Interviews Questions Java Spring Hibernate DevOps Testing API BigData Web Erlang AI Database Integration Cloud Python Scala Tools Golang SAP	About Javapedia.net Javapedia.net is for Java and J2EE developers, technologist and college students who prepare of interview. Also this site includes many practical examples. This site is developed using J2EE technologies by Steve Antony, a senior Developer/lead at one of the logistics based company. Follow Javapedia updates
	contact: javatutorials2016[at]gmail[dot]com
Kindly consider donating for maintaining this website. Thanks.
	Copyright © 2026, javapedia.net, all rights reserved. Privacy Policy · Terms of Service.

DevOps / ArgoCD interview questions

How do ArgoCD Sync Waves and Sync Hooks work together to control deployment ordering?

Sync Waves

Sync Hooks

Comments & Discussions

Recently added questions