Migration, Versioning, and Rollback Playbooks

Reliable ACF migrations are release workflows, not one-time scripts.

Learning Focus

You will design migration playbooks that combine schema version tracking, idempotent data transforms, and rollback commands so ACF Pro changes can be released and reversed with confidence.

ACF Pro Required

This lesson uses ACF Pro-focused workflows, including Local JSON delivery patterns and complex field migrations with Repeater or Flexible Content structures.

Concept Overview

ACF migrations usually involve two moving parts at once: schema changes and content value moves. Schema changes include renamed fields, new field groups, adjusted return formats, and modified location rules. Content value moves include copying old values into new fields, reshaping arrays, and cleaning stale metadata. When teams treat migration as only a code deploy, they miss the data lifecycle and create silent production drift.

Versioning is the coordination layer that prevents repeated or partial application. A migration should be keyed to an explicit schema version option, run idempotently, and emit measurable results. Idempotency means the same migration command can run again without duplicating writes or destroying values. Without that property, retries after deployment interruptions become dangerous.

Rollback planning belongs in the first draft of migration code, not in incident response. You need a backup signal per migrated post, a machine-readable list of touched IDs, and a command that can restore pre-migration values. This should be validated in staging with representative records before production release. A rollback that exists only as a vague idea is not a rollback.

For enterprise ACF projects, Local JSON should be part of this same playbook. You should verify field group fingerprints before migration starts, then confirm no unexpected schema drift after deployment. That gives you a reproducible chain from repository state to runtime registry.

Core Idea

Ship migration as a repeatable pipeline: verify schema state, run idempotent transforms, record exactly what changed, and keep rollback executable at command level.

Why It Matters

Approach	What Happens	Impact in Production
Version-gated idempotent migrations	Commands can be retried safely after interruptions	Lower release risk and cleaner incident recovery
Save backup meta before writing new values	Rollback can restore exact pre-migration content	Faster mitigation during failed releases
Store touched post IDs in option log	Teams know exactly what changed and where	Targeted audits instead of broad manual review
Compare schema fingerprint before and after release	Unexpected field-group drift is caught early	Better configuration integrity across environments
Run direct destructive migration with no dry run (wrong pattern)	In-place overwrite may lose legacy values	Data loss risk and long recovery windows

Reference Table

Term/API	Signature/Syntax	Purpose	Key Notes
`acf/settings/save_json`	`add_filter('acf/settings/save_json', callable $callback, int $priority = 10, int $accepted_args = 1): string`	Set canonical Local JSON export path	Keep path consistent across team environments
`acf/settings/load_json`	`add_filter('acf/settings/load_json', callable $callback, int $priority = 10, int $accepted_args = 1): array`	Add one or more Local JSON import paths	Supports shared package or release-candidate paths
`acf_get_field_groups()`	`acf_get_field_groups(array $filter = []): array`	Read runtime-registered field groups	Useful for schema baseline and drift checks
`get_field()`	`get_field(string $selector, int	string $post_id = false, bool $format_value = true): mixed`	Read source value during migration
`update_field()`	`update_field(string $selector, mixed $value, int	string $post_id = false): int	bool`
`WP_Query` ID batch	`new WP_Query(['post_type' => 'page', 'fields' => 'ids', 'posts_per_page' => 200, 'no_found_rows' => true])`	Scan large content sets efficiently	Reduces memory and query overhead
`update_option()`	`update_option(string $option, mixed $value, bool	string $autoload = null): bool`	Persist schema version and migration logs
`wp eval-file`	`wp eval-file <path>`	Run migration script from CLI	Good for controlled one-off operations
`wp db export`	`wp db export <file>`	Create pre-migration backup snapshot	Mandatory for high-risk transformations
`wp db import`	`wp db import <file>`	Restore previous DB state in full rollback	Use only with approved incident playbook

ACF Pro Required

Rows involving Local JSON and migrations of Pro field structures such as Repeater or Flexible Content require ACF Pro workflows.

Practical Use Cases

1. Idempotent hero field rename migration with schema version gate

Your team is replacing hero_title with service_headline across service pages. Some pages already have the new field populated, and migration must skip those records. You need a dry run mode, backup meta for changed rows, and an option-based schema version marker.

Register a WP-CLI command from acf/init so it runs only when ACF is available.
Query page IDs in predictable batches.
Copy value only when old field is non-empty and new field is empty.
Save backup value before write and store touched IDs for audit.
Update clinic_acf_schema_version after successful live run.

wp-content/mu-plugins/clinic-acf-migration-hero-headline.php
<?php

declare(strict_types=1);

add_action('acf/init', function (): void {
    if (!defined('WP_CLI') || !WP_CLI || !class_exists('WP_CLI')) {
        return;
    }

    WP_CLI::add_command('clinic-acf migrate-hero-headline', function (array $args, array $assocArgs): void {
        $dryRun = isset($assocArgs['dry-run']) ? ((int) $assocArgs['dry-run'] === 1) : true;
        $batch = isset($assocArgs['batch']) ? max(1, (int) $assocArgs['batch']) : 200;

        $query = new WP_Query([
            'post_type' => 'page',
            'post_status' => 'publish',
            'fields' => 'ids',
            'posts_per_page' => $batch,
            'no_found_rows' => true,
            'meta_query' => [
                [
                    'key' => '_wp_page_template',
                    'value' => 'templates/service-landing.php',
                ],
            ],
        ]);

        $scanned = 0;
        $migrated = 0;
        $skipped = 0;
        $touched = [];

        foreach ((array) $query->posts as $rawId) {
            $postId = (int) $rawId;
            $scanned++;

            $legacy = trim((string) get_field('hero_title', $postId));
            $target = trim((string) get_field('service_headline', $postId));

            if ($legacy === '' || $target !== '') {
                $skipped++;
                continue;
            }

            if ($dryRun) {
                $migrated++;
                continue;
            }

            update_post_meta($postId, '_migration_v2026_02_hero_title_backup', $legacy);
            update_field('service_headline', $legacy, $postId);
            $touched[] = $postId;
            $migrated++;
        }

        WP_CLI::log('Scanned: ' . $scanned);
        WP_CLI::log(($dryRun ? 'Would migrate: ' : 'Migrated: ') . $migrated);
        WP_CLI::log('Skipped: ' . $skipped);

        if (!$dryRun) {
            update_option('clinic_acf_migration_v2026_02_hero_headline_ids', $touched, false);
            update_option('clinic_acf_schema_version', '2026.02.0', false);
            WP_CLI::success('Updated schema version to 2026.02.0.');
            return;
        }

        WP_CLI::success('Dry run complete.');
    });
});

terminal: command
wp clinic-acf migrate-hero-headline --dry-run=1 --batch=200
wp clinic-acf migrate-hero-headline --dry-run=0 --batch=200
wp option get clinic_acf_schema_version
wp post meta get 1204 _migration_v2026_02_hero_title_backup

terminal: output
Scanned: 200
Would migrate: 37
Skipped: 163
Success: Dry run complete.
Scanned: 200
Migrated: 37
Skipped: 163
Success: Updated schema version to 2026.02.0.
2026.02.0
Permanent Hair Reduction Program

warning

Never run the live command before dry run output is reviewed by another engineer. Dry run counts are your first safety gate.

2. Local JSON schema fingerprint audit before and after migration

A deployment pipeline promotes ACF field groups through repository commits. You need a machine-readable fingerprint to confirm runtime schema matches committed JSON. This prevents running data transforms against an unexpected field registry.

Set explicit save and load paths for Local JSON.
Register a CLI command that calculates a deterministic fingerprint from JSON files.
Compare current fingerprint and group count against saved baseline.
Optionally write baseline during release preparation.
Block migration steps when mismatch is detected.

wp-content/themes/clinic-headless/inc/acf/schema-fingerprint-audit.php
<?php

declare(strict_types=1);

add_filter('acf/settings/save_json', function (string $path): string {
    return get_stylesheet_directory() . '/acf-json';
}, 10, 1);

add_filter('acf/settings/load_json', function (array $paths): array {
    $paths[] = get_stylesheet_directory() . '/acf-json';
    $paths[] = WP_CONTENT_DIR . '/acf-json-release-candidate';
    return array_values(array_unique($paths));
}, 10, 1);

add_action('acf/init', function (): void {
    if (!defined('WP_CLI') || !WP_CLI || !class_exists('WP_CLI')) {
        return;
    }

    WP_CLI::add_command('clinic-acf schema-audit', function (array $args, array $assocArgs): void {
        $writeBaseline = isset($assocArgs['write-baseline']) ? ((int) $assocArgs['write-baseline'] === 1) : false;

        $jsonPath = get_stylesheet_directory() . '/acf-json';
        $files = glob($jsonPath . '/*.json');
        $files = is_array($files) ? $files : [];
        sort($files);

        $parts = [];
        foreach ($files as $file) {
            $contents = file_get_contents($file);
            $parts[] = basename($file) . ':' . hash('sha256', (string) $contents);
        }

        $fingerprint = hash('sha256', implode('|', $parts));
        $groups = acf_get_field_groups();
        $groupCount = is_array($groups) ? count($groups) : 0;

        $current = [
            'fingerprint' => $fingerprint,
            'group_count' => $groupCount,
            'generated_at' => gmdate('c'),
        ];

        if ($writeBaseline) {
            update_option('clinic_acf_schema_fingerprint', $current, false);
            WP_CLI::log('groups=' . $groupCount);
            WP_CLI::log('fingerprint=' . $fingerprint);
            WP_CLI::success('Schema baseline saved.');
            return;
        }

        $baseline = get_option('clinic_acf_schema_fingerprint', []);
        $baselineFp = is_array($baseline) ? (string) ($baseline['fingerprint'] ?? '') : '';
        $baselineCount = is_array($baseline) ? (int) ($baseline['group_count'] ?? 0) : 0;

        WP_CLI::log('groups=' . $groupCount);
        WP_CLI::log('fingerprint=' . $fingerprint);

        if ($baselineFp === '' || $baselineCount === 0) {
            WP_CLI::warning('No baseline found. Run with --write-baseline=1 first.');
            return;
        }

        if ($baselineFp !== $fingerprint || $baselineCount !== $groupCount) {
            WP_CLI::error('Schema mismatch detected. Stop migration and reconcile Local JSON.');
            return;
        }

        WP_CLI::success('Schema audit passed.');
    });
});

terminal: command
wp clinic-acf schema-audit --write-baseline=1
wp clinic-acf schema-audit
wp option get clinic_acf_schema_fingerprint --format=json
ls wp-content/themes/clinic-headless/acf-json/

terminal: output
groups=18
fingerprint=ca1848e6c4a9fbf9d2dd25521269f8486639fc7675d675c891f2eb5b8b3f4b60
Success: Schema baseline saved.
groups=18
fingerprint=ca1848e6c4a9fbf9d2dd25521269f8486639fc7675d675c891f2eb5b8b3f4b60
Success: Schema audit passed.
{"fingerprint":"ca1848e6c4a9fbf9d2dd25521269f8486639fc7675d675c891f2eb5b8b3f4b60","group_count":18,"generated_at":"2026-02-23T19:14:40+00:00"}
group_64f1a100ad31.json
group_64f1a2a9f5f2.json
group_64f1a5e4a762.json

note

Schema fingerprint mismatch does not always mean bad code. It can indicate uncommitted JSON, wrong branch, or environment-specific path drift. Treat it as a release stop signal until explained.

3. Edge case: destructive overwrite during rich-text-to-repeater migration

A team migrates case_summary plain text into a new Repeater case_summary_blocks. A naive script overwrites records every run and keeps no backup. When the new rendering fails for some posts, there is no safe recovery path.

Fragile Pattern (Bad)

wp-content/mu-plugins/clinic-acf-migration-case-summary-fragile.php
<?php

declare(strict_types=1);

add_action('acf/init', function (): void {
    if (!defined('WP_CLI') || !WP_CLI || !class_exists('WP_CLI')) {
        return;
    }

    WP_CLI::add_command('clinic-acf migrate-case-summary-fragile', function (): void {
        $ids = get_posts(['post_type' => 'case_study', 'post_status' => 'publish', 'fields' => 'ids', 'numberposts' => -1]);
        foreach ((array) $ids as $id) {
            $text = (string) get_field('case_summary', (int) $id);
            update_field('case_summary_blocks', [['case_summary_block_text' => $text]], (int) $id);
        }
        WP_CLI::success('Migration complete.');
    });
});

Robust Pattern (Good)

wp-content/mu-plugins/clinic-acf-migration-case-summary-v2.php
<?php

declare(strict_types=1);

add_action('acf/init', function (): void {
    if (!defined('WP_CLI') || !WP_CLI || !class_exists('WP_CLI')) {
        return;
    }

    WP_CLI::add_command('clinic-acf migrate-case-summary-v2', function (array $args, array $assocArgs): void {
        $dryRun = isset($assocArgs['dry-run']) ? ((int) $assocArgs['dry-run'] === 1) : true;

        $query = new WP_Query([
            'post_type' => 'case_study',
            'post_status' => 'publish',
            'fields' => 'ids',
            'posts_per_page' => -1,
            'no_found_rows' => true,
        ]);

        $migrated = 0;
        $skipped = 0;
        $touchedIds = [];

        foreach ((array) $query->posts as $rawId) {
            $postId = (int) $rawId;
            $legacy = trim((string) get_field('case_summary', $postId));
            $blocks = get_field('case_summary_blocks', $postId, false);
            $hasBlocks = is_array($blocks) && $blocks !== [];

            if ($legacy === '' || $hasBlocks) {
                $skipped++;
                continue;
            }

            if ($dryRun) {
                $migrated++;
                continue;
            }

            update_post_meta($postId, '_backup_case_summary_v1', $legacy);
            $payload = [
                [
                    'case_summary_block_title' => 'Summary',
                    'case_summary_block_text' => $legacy,
                ],
            ];

            update_field('case_summary_blocks', $payload, $postId);
            update_post_meta($postId, '_migration_case_summary_v2_applied', '1');
            $touchedIds[] = $postId;
            $migrated++;
        }

        WP_CLI::log(($dryRun ? 'Would migrate: ' : 'Migrated: ') . $migrated);
        WP_CLI::log('Skipped: ' . $skipped);

        if (!$dryRun) {
            update_option('clinic_acf_migration_case_summary_v2_ids', $touchedIds, false);
            update_option('clinic_acf_migration_case_summary_v2_completed_at', gmdate('c'), false);
        }

        WP_CLI::success($dryRun ? 'Dry run complete.' : 'Migration complete.');
    });

    WP_CLI::add_command('clinic-acf rollback-case-summary-v2', function (array $args, array $assocArgs): void {
        $singlePostId = isset($assocArgs['post_id']) ? (int) $assocArgs['post_id'] : 0;
        $targets = [];

        if ($singlePostId > 0) {
            $targets[] = $singlePostId;
        } else {
            $saved = get_option('clinic_acf_migration_case_summary_v2_ids', []);
            $targets = array_map('intval', is_array($saved) ? $saved : []);
        }

        $restored = 0;
        foreach ($targets as $postId) {
            $backup = (string) get_post_meta($postId, '_backup_case_summary_v1', true);
            if ($backup === '') {
                continue;
            }

            update_field('case_summary', $backup, $postId);
            update_field('case_summary_blocks', [], $postId);
            delete_post_meta($postId, '_migration_case_summary_v2_applied');
            $restored++;
        }

        WP_CLI::success('Rollback restored ' . $restored . ' posts.');
    });
});

terminal: command
wp clinic-acf migrate-case-summary-v2 --dry-run=1
wp clinic-acf migrate-case-summary-v2 --dry-run=0
wp post meta get 991 _backup_case_summary_v1
wp clinic-acf rollback-case-summary-v2 --post_id=991
wp eval 'var_export(get_field("case_summary", 991)); echo PHP_EOL;'

terminal: output
Would migrate: 54
Skipped: 312
Success: Dry run complete.
Migrated: 54
Skipped: 312
Success: Migration complete.
Candidate improved skin texture score by 37 percent in 8 weeks.
Success: Rollback restored 1 posts.
'Candidate improved skin texture score by 37 percent in 8 weeks.'

warning

Do not clear backup meta in the same deployment as migration. Keep backups until the new rendering path has passed production monitoring thresholds.

Common Mistakes

Mistake	Root Cause	What Breaks in Production	Correct Pattern
Live migration executed before dry run review	Delivery pressure and no checklist gate	Unexpected write volume and silent bad mappings	`wp clinic-acf migrate-hero-headline --dry-run=1 --batch=200`
No per-record backup before target write	Assumes migration will always succeed	Rollback cannot restore original values	`update_post_meta($postId, '_backup_case_summary_v1', $legacy);`
Schema version not persisted	No state gate for re-runs	Same migration may run repeatedly on deploy	`wp option get clinic_acf_schema_version`
Local JSON drift ignored	Runtime field groups differ from repo	Migration targets wrong field keys or names	`wp clinic-acf schema-audit`
Rollback path untested in staging	Team focuses only on forward success	Incident response time increases sharply	`wp clinic-acf rollback-case-summary-v2 --post_id=991`
Migration logs not retained	Touched IDs never recorded	Audits and selective fixes become manual	`wp option get clinic_acf_migration_case_summary_v2_ids --format=json`

Deep Dive: Why Field Key Drift Is Harder to Debug Than It Looks

Field key drift appears when one environment has updated JSON while another still registers older field definitions. A migration may still run, but values can land in unexpected meta keys or fail to populate UI as expected. This bug is subtle because command output can look successful while editors report missing values later. The fastest way to detect drift is comparing runtime group keys and your stored schema fingerprint before migration. When the fingerprint differs, pause release and reconcile JSON sources first.

wp eval 'print_r(array_map(static fn($g) => $g["key"], acf_get_field_groups()));'

Best Practices

Keep one release schema option and verify each deploy with wp option get clinic_acf_schema_version.
Require dry run output in deployment notes: wp clinic-acf migrate-case-summary-v2 --dry-run=1.
Save touched IDs for every migration using update_option('clinic_acf_migration_<id>_ids', $ids, false);.
Validate Local JSON fingerprint before running data writes: wp clinic-acf schema-audit.
Back up old field value before each write using update_post_meta($postId, '_backup_<field>', $oldValue);.
Keep rollback command executable per record and batch mode in the same release artifact.
Review migrated sample records with CLI spot checks such as wp post meta get 991 _backup_case_summary_v1.

Hands-On Practice

Exercise 1: Create migration drill records

Run:

wp post create --post_title="Case Migration Drill 1" --post_status=publish --post_type=case_study
wp post create --post_title="Case Migration Drill 2" --post_status=publish --post_type=case_study

After completing this exercise, running wp post list --post_type=case_study --search="Case Migration Drill" --fields=ID,post_title --format=table should return two rows.

Exercise 2: Seed legacy field values for migration

Run:

wp eval '$id=(int)get_page_by_title("Case Migration Drill 1", OBJECT, "case_study")->ID; update_field("case_summary","Legacy summary one",$id); echo $id . PHP_EOL;'
wp eval '$id=(int)get_page_by_title("Case Migration Drill 2", OBJECT, "case_study")->ID; update_field("case_summary","Legacy summary two",$id); echo $id . PHP_EOL;'

After completing this exercise, running wp eval '$id=(int)get_page_by_title("Case Migration Drill 1", OBJECT, "case_study")->ID; var_export(get_field("case_summary",$id)); echo PHP_EOL;' should return Legacy summary one.

Exercise 3: Run dry run and confirm candidate count

Run:

wp clinic-acf migrate-case-summary-v2 --dry-run=1

After completing this exercise, output should include:

Would migrate:
Skipped:
Success: Dry run complete.

Exercise 4: Execute live migration and verify backup meta

Run:

wp clinic-acf migrate-case-summary-v2 --dry-run=0
wp eval '$id=(int)get_page_by_title("Case Migration Drill 1", OBJECT, "case_study")->ID; echo get_post_meta($id,"_backup_case_summary_v1",true) . PHP_EOL;'

After completing this exercise, output should include:

Success: Migration complete.
Legacy summary one

Exercise 5: Perform targeted rollback validation

Run:

wp eval '$id=(int)get_page_by_title("Case Migration Drill 1", OBJECT, "case_study")->ID; echo $id . PHP_EOL;'
wp clinic-acf rollback-case-summary-v2 --post_id=<returned-id>
wp eval '$id=(int)get_page_by_title("Case Migration Drill 1", OBJECT, "case_study")->ID; var_export(get_field("case_summary",$id)); echo PHP_EOL;'

After completing this exercise, output should include:

Success: Rollback restored 1 posts.
'Legacy summary one'

CLI Reference

Command	Purpose	Real Example Output
`wp clinic-acf migrate-hero-headline --dry-run=1 --batch=200`	Preview rename migration effect	`Scanned: 200` `Would migrate: 37` `Skipped: 163`
`wp clinic-acf migrate-hero-headline --dry-run=0 --batch=200`	Apply rename migration	`Migrated: 37` `Success: Updated schema version to 2026.02.0.`
`wp option get clinic_acf_schema_version`	Read active schema version gate	`2026.02.0`
`wp clinic-acf schema-audit --write-baseline=1`	Persist Local JSON fingerprint baseline	`groups=18` `Success: Schema baseline saved.`
`wp clinic-acf schema-audit`	Compare runtime schema with baseline	`Success: Schema audit passed.`
`wp option get clinic_acf_schema_fingerprint --format=json`	Inspect stored schema fingerprint object	`{"fingerprint":"ca1848e6c4a9fbf9d2dd25521269f8486639fc7675d675c891f2eb5b8b3f4b60","group_count":18,"generated_at":"2026-02-23T19:14:40+00:00"}`
`wp post meta get 991 _backup_case_summary_v1`	Read backup value for rollback safety	`Candidate improved skin texture score by 37 percent in 8 weeks.`
`wp clinic-acf rollback-case-summary-v2 --post_id=991`	Restore one migrated record	`Success: Rollback restored 1 posts.`
`ls wp-content/themes/clinic-headless/acf-json/`	Inspect Local JSON files before release	`group_64f1a100ad31.json` `group_64f1a2a9f5f2.json` `group_64f1a5e4a762.json`
`grep -R '"key": "group_' wp-content/themes/clinic-headless/acf-json/*.json`	Verify field group keys present in JSON	`wp-content/themes/clinic-headless/acf-json/group_64f1a100ad31.json: "key": "group_64f1a100ad31"`

Rollback Pattern

Use this forward and rollback sequence for migration releases. Run forward commands only after backup and dry run checks are green.

terminal: forward migration sequence
wp db export "./backups/pre-acf-v2026-02.sql"
wp clinic-acf schema-audit --write-baseline=1
wp clinic-acf migrate-hero-headline --dry-run=0 --batch=500
wp clinic-acf migrate-case-summary-v2 --dry-run=0
wp option update clinic_acf_schema_version "2026.02.0"

terminal: forward migration output
Success: Exported to './backups/pre-acf-v2026-02.sql'.
Success: Schema baseline saved.
Success: Updated schema version to 2026.02.0.
Success: Migration complete.
Success: Updated 'clinic_acf_schema_version' option.

If production verification fails, execute rollback immediately.

terminal: rollback sequence
wp clinic-acf rollback-case-summary-v2
wp option update clinic_acf_schema_version "2026.01.0"
wp eval 'echo get_option("clinic_acf_schema_version") . PHP_EOL;'
wp post meta get 991 _backup_case_summary_v1

terminal: rollback output
Success: Rollback restored 54 posts.
Success: Updated 'clinic_acf_schema_version' option.
2026.01.0
Candidate improved skin texture score by 37 percent in 8 weeks.

What's Next

Continue to Module 9 Lesson 1: ACF Test Strategy, Fixtures, and Scenario Matrix.
Return to Module 8 Overview to connect migration operations with your headless delivery standards.
Related lesson: CI/CD Pipeline Quality Gates and Release Checks.
Related lesson: Local JSON and Version Control Workflow.

tip

Revisit this lesson before any release that renames fields or changes field structures, because those are the moments where backup discipline and rollback readiness prevent prolonged incidents.

Concept Overview​

Why It Matters​

Reference Table​

Practical Use Cases​

1. Idempotent hero field rename migration with schema version gate​

2. Local JSON schema fingerprint audit before and after migration​

3. Edge case: destructive overwrite during rich-text-to-repeater migration​

Fragile Pattern (Bad)​

Robust Pattern (Good)​

Common Mistakes​

Best Practices​

Hands-On Practice​

Exercise 1: Create migration drill records​

Exercise 2: Seed legacy field values for migration​

Exercise 3: Run dry run and confirm candidate count​

Exercise 4: Execute live migration and verify backup meta​

Exercise 5: Perform targeted rollback validation​

CLI Reference​

Rollback Pattern​

What's Next​

Concept Overview

Why It Matters

Reference Table

Practical Use Cases

1. Idempotent hero field rename migration with schema version gate

2. Local JSON schema fingerprint audit before and after migration

3. Edge case: destructive overwrite during rich-text-to-repeater migration

Fragile Pattern (Bad)

Robust Pattern (Good)

Common Mistakes

Best Practices

Hands-On Practice

Exercise 1: Create migration drill records

Exercise 2: Seed legacy field values for migration

Exercise 3: Run dry run and confirm candidate count

Exercise 4: Execute live migration and verify backup meta

Exercise 5: Perform targeted rollback validation

CLI Reference

Rollback Pattern

What's Next