How do you build, sign, and publish Android apps?

Question

IT Interview Practice · Accepted Answer

Releasing an Android app involves building a **release version**, **signing** it (required), and publishing to **Google Play** (or other stores), along with versioning, testing tracks, and ongoing updates. Understanding the process is important for shipping apps.

## Building a release version

```text
→ Build a RELEASE variant (optimized, minified/shrunk via R8/ProGuard) — not debug
→ Produce an APP BUNDLE (.aab) — the preferred format for Google Play (Play generates
  optimized APKs per device); or an APK
```

## App signing (required)

```text
ALL Android apps must be SIGNED with a certificate to be installed/updated:
  → sign with a KEYSTORE (a signing key you must keep SAFE — losing it means you can't
    update the app with the same identity!)
  → PLAY APP SIGNING → Google manages your signing key (recommended; you upload with an
    upload key, Google signs) — protects against key loss
→ The signature proves the app's authorship and that updates come from the same developer.
```

## Publishing to Google Play

```text
→ Google Play CONSOLE: create the app, upload the AAB, fill the store listing (description,
  screenshots, icon), set content rating, privacy policy, pricing
→ TESTING TRACKS — internal / closed (alpha) / open (beta) testing before production
  → roll out gradually; gather feedback; catch issues
→ Review process (policy compliance); then production release (staged rollout possible)
→ VERSIONING — versionCode (integer, must increase) + versionName (display) for updates
```

## Why it matters

Understanding how to build, sign, and publish Android apps is important senior-level knowledge because **shipping apps to users is the goal**, and the release process has specific, important requirements, so it's valuable for delivering real apps.

Understanding **building a release version** (an optimized, shrunk release variant — not debug — produced as an **App Bundle** which Google Play prefers, generating device-optimized APKs) is the starting point.

Understanding **app signing** is essential and critical: **all Android apps must be signed** to be installed and updated, and the signing key must be kept safe (**losing it means you can't update the app with the same identity** — a serious risk), which is why **Play App Signing** (Google managing the signing key, with you uploading via an upload key) is recommended to protect against key loss — understanding this signing requirement and key management is important practical and risk-management knowledge.

Understanding **publishing to Google Play** (using the Play Console to upload the bundle, create the store listing with required metadata and privacy policy, use **testing tracks** — internal/closed/open testing before production to catch issues and gather feedback, navigate the review process, and do staged rollouts) reflects the real release workflow.

Understanding **versioning** (versionCode that must increase for updates, versionName for display) is necessary for managing updates correctly.

Since shipping apps to users is the goal of development and the release process (release builds, the required signing with its key-management risks, Play Console publishing with testing tracks, and versioning) has specific important requirements, and since understanding it is necessary for actually delivering and updating apps, understanding how to build, sign, and publish Android apps is important senior-level knowledge — necessary for shipping real apps to users, reflecting the end-to-end understanding (especially the critical signing/key-management aspect) expected for senior roles responsible for releasing and maintaining production Android apps.

Building a release version

App signing (required)

Publishing to Google Play

Why it matters

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