Skip to content

Lab 25: Tech Lead Challenge

Field Value
Tier 5 — Capstone
Estimated Time 3 hours
Prerequisites All prior tiers
Auto-Grade Yes

Scenario

You have been promoted to Tech Lead for the platform team. In your first week, five critical decisions land on your desk, each with incomplete information and competing stakeholders. There is no clearly right answer — you need to analyze trade-offs, make a defensible decision, and document your reasoning. Then you need to implement a proof-of-concept for at least three of the five decisions.

This lab tests your ability to think at a systems level, balance competing priorities, communicate technical decisions to non-technical stakeholders, and turn decisions into working infrastructure.

Decisions

  1. Cluster strategy: Single large cluster vs. multiple small clusters per team. Constraint: 30 teams, budget for 500 nodes total.

  2. GitOps tooling: ArgoCD vs. Flux vs. custom pipeline. Constraint: 4 engineers to maintain, 200+ microservices.

  3. Secret management: Vault vs. Sealed Secrets vs. External Secrets Operator. Constraint: SOC2 compliance required, 3 environments.

  4. Observability stack: Datadog vs. self-hosted (Prometheus/Grafana/Loki). Constraint: $50k/year budget, 10TB logs/month.

  5. Deployment strategy: Blue-green vs. canary vs. rolling update as default. Constraint: Some services need zero-downtime, others are batch jobs.

Objectives

  • Write a decision document for each of the 5 decisions (/tmp/lab-techlead/decisions/)
  • Each decision includes: context, options analyzed, trade-offs, recommendation, reasoning
  • Implement PoC 1: Deploy multi-namespace cluster layout (decision 1)
  • Implement PoC 2: Deploy a GitOps-style workflow (decision 2)
  • Implement PoC 3: Deploy a secret management solution (decision 3)
  • All PoCs are running in namespace lab-techlead
  • Write an executive summary to /tmp/lab-techlead/executive-summary.txt

Setup

./setup.sh

Creates the working environment and namespace.

Hints

Hint 1: Decision document format Use the ADR (Architecture Decision Record) format: - Status: Proposed/Accepted/Deprecated - Context: Why this decision is needed - Options: 2-3 options with pros/cons - Decision: What we chose and why - Consequences: What this means going forward
Hint 2: Multi-namespace PoC Create 3 namespaces representing different teams. Deploy a sample app in each with resource quotas, RBAC, and network isolation. This proves the single-cluster multi-tenant model works.
Hint 3: GitOps PoC Create a git repository with Kubernetes manifests. Write a script that watches the repo for changes and applies them (simplified ArgoCD). Deploy it as a pod.
Hint 4: Secret management PoC Deploy Sealed Secrets or a simulated Vault. Create an encrypted secret, deploy it, and verify the application can read the decrypted value.
Hint 5: Executive summary 1-2 pages. Written for non-technical executives. Focus on business impact, cost, risk, and timeline. Avoid jargon. Each decision: one paragraph.

Grading

./grade.sh

Solution

See the solution/ directory for sample decisions and PoC implementations.