Design GitOps Workflow - System Design | WinJob

Problem Statement: GitOps as Cluster Source of Truth

GitOps treats Git as the single source of truth for Kubernetes (and often VM) desired state. Argo CD, Flux, and GitLab Agent continuously reconcile live clusters to manifests in Git—PRs become change requests, merges trigger automated sync, and rollbacks are often git revert.

Core interview story

Declarative manifests in Git (Helm, Kustomize, plain YAML, OCI artifacts).
Continuous reconciliation — operators detect drift and repair or alert.
Environment promotion via branches or directories (env/staging, env/prod).
Progressive delivery with sync waves, health checks, and optional Argo Rollouts.

Scale anchors (state aloud)

400 microservices across 12 EKS/GKE/AKS clusters, ~2,000 Applications in Argo CD.
~800 manifest commits/day; webhook bursts ~30 events/sec after large merges.
Reconciliation: poll + webhook driven; target p95 sync latency < 3 min for non-prod, manual/auto gates for prod.

javaOne Dark Pro

1 public final class SyncPolicyGate {
2   public boolean allowAutoSync(boolean prod, boolean prMerged, boolean policyPass) {
3     if (prod) return prMerged && policyPass;
4     return policyPass;
5   }
6 }

pythonOne Dark Pro

1 from dataclasses import dataclass
2  
3 @dataclass
4 class DesiredRevision:
5     repo_url: str
6     target_revision: str
7     path: str
8  
9 def out_of_sync(live_hash: str, desired_hash: str) -> bool:
10     return live_hash != desired_hash

typescriptOne Dark Pro

1 interface ApplicationSpec {
2   project: string;
3   destinationCluster: string;
4   path: string;
5   autoSync: boolean;
6 }
7  
8 export function shouldReconcile(app: ApplicationSpec, driftDetected: boolean): boolean {
9   return driftDetected || app.autoSync;
10 }

How to open this one

The framing that lands for GitOps is Git as the single source of truth with a controller continuously reconciling the cluster toward the committed manifests — so a deploy is a merge and a rollback is a git revert. Lead with the reconcile loop and drift detection (the controller reverts manual kubectl changes back to what Git declares), and the failure story that proves it: someone hot-patches prod by hand, the controller notices the drift and restores the declared state. That shows you understand GitOps makes the repo, not the cluster, authoritative.

Key Highlights

•GitOps workflow limits blast radius by measuring candidate traffic before full promotion.
•Baseline comparison beats global averages when traffic is diurnal.
•Fail closed on stale metrics or failed mesh ACKs.
•Expand-contract migrations are mandatory under split traffic.

1	public final class SyncPolicyGate {
2	public boolean allowAutoSync(boolean prod, boolean prMerged, boolean policyPass) {
3	if (prod) return prMerged && policyPass;
4	return policyPass;
5	}
6	}

1	from dataclasses import dataclass
2
3	@dataclass
4	class DesiredRevision:
5	repo_url: str
6	target_revision: str
7	path: str
8
9	def out_of_sync(live_hash: str, desired_hash: str) -> bool:
10	return live_hash != desired_hash

1	interface ApplicationSpec {
2	project: string;
3	destinationCluster: string;
4	path: string;
5	autoSync: boolean;
6	}
7
8	export function shouldReconcile(app: ApplicationSpec, driftDetected: boolean): boolean {
9	return driftDetected \|\| app.autoSync;
10	}

Problem Statement: GitOps as Cluster Source of Truth

Core interview story

Scale anchors (state aloud)

How to open this one

Key Highlights

Section Rescue Kit