Upgrade Apache Spark applications between major versions with a structured, phase-by-phase workflow. When to Use - Migrating from Spark 2.x → 3.x or Spark 3.x → 4.x - Updating PySpark, Spark SQL, or Structured Streaming applications - Resolving deprecation warnings before a Spark version bump Workflow Overview 1. Inventory & Impact Analysis — Scan the codebase and assess scope 2. Build File Updates — Bump Spark/Scala/Java dependencies 3. API Migration — Replace deprecated and removed APIs 4. Configuration Migration — Update Spark config properties 5. SQL & DataFrame Migration — Fix query-leve…