Course 3 of 7 · The deployment/infra track
Helm, from newcomer to interview-ready
How this repo turns one template into ~106 charts of Kubernetes objects — per environment, per customer.
Course 2 taught the Kubernetes objects and kept repeating one thing: this repo doesn't hand-write them — it generates them from Helm templates. This is where that promise pays off. Helm is the single biggest topic in the whole deployment domain: ~106 charts, all built on one shared library chart, layered across the env×org matrix. Three parts, built one at a time. Lessons are short — one win each. Read them in order.
Part 1 — Helm fundamentals available now
The vocabulary and the templating engine everything else builds on.
1 · What Helm is & why
The package manager + templating engine for K8s — chart, release, values.
ready2 · Chart anatomy
Chart.yaml, templates/, values.yaml, _helpers.tpl.
3 · Templates & the Go engine
.Values, built-in objects, functions/pipelines, include/tpl.
4 · Values & overrides
Precedence (values.yaml → -f → --set) + env×org layering.
Part 2 — This repo's library-chart architecture available now
The clever bit: one library chart generates almost every object in the repo.
5 · Named templates & helpers
define/include, the fullname/labels pattern, util.*.
6 · Library charts & the copy model
type: library, libs/util, update_deps.sh vs subcharts.
7 · Hooks & lifecycle
pre/post install-upgrade, the DB-migration hook, weights & delete-policy.
ready8 · Releases & Skaffold
install/upgrade vs template; how Skaffold drives Helm (Course 1's render).
Part 3 — Secrets, scale & operations available now
The production concerns: encrypted values, 106 charts, and safe upgrades.
9 · SOPS secrets in Helm
Encrypted values → decrypt → KMS/Workload Identity; keeping secrets out of git.
ready10 · Values at scale
~106 charts, the env×org matrix, global values, staying DRY via the library.
ready11 · Upgrade, rollback & releases
helm upgrade/rollback/history; atomic; drift.
12 · Chart quality
lint, template/dry-run, versioning, and the drift-check pattern.
Part 4 — Senior Helm judgment new
The senior stretch — ownership boundaries, copy-model trade-offs, values-contract design, release safety, review judgment, and interview-grade answers.
13 · Helm truthfulness
Tell the real Helm story accurately: what Helm truly owns, what Skaffold/Kubernetes own, and why that boundary matters.
new14 · The copy model
Reason about why the repo copies libs/util, what that buys, and where it creates drift risk.
15 · Values as a contract
Treat values like a chart API: defaults, globals, layering, and maintainability at scale.
new16 · Hooks and release safety
Explain hook timing, migration safety, revisions, and rollback realism without overclaiming.
new17 · Reviewing Helm designs
Review helper structure, values contracts, drift risk, and chart operability with sharper questions.
new18 · Senior interview questions
High-signal Helm questions with answer shapes that sound like real operational experience.
new19 · Mock senior interview pack
A retrieval-first mock round with scoring and strong answer points.
newReference shelf
Cheat sheet
Dense revision sheet + helm commands + interview one-liners.
Glossary
The canonical vocabulary, opinionated.
Repo Helm map
Ground truth: the library chart, service charts, values, SOPS.
Resources
helm.sh docs, helm-secrets/SOPS, the cert, plus senior Helm judgment topics.
Senior backend playbook
The compressed version of the new senior part: ownership boundaries, copy-model trade-offs, values contracts, release safety, review judgment, and interview answers.