AI Code Review for Framework Migrations

The migration halfway problem

Every framework migration follows the same pattern. The team starts with enthusiasm, migrates the simplest components first, and makes rapid progress. Then they hit the complex parts: deeply integrated modules, components with implicit dependencies on the old framework's behaviour, and patterns that have no direct equivalent in the new framework. Progress slows. Feature work continues in parallel. The migration stalls at 60 or 70 percent complete.

This halfway state is where most of the damage occurs. The codebase now has two ways of doing everything. New code uses the new framework. Old code uses the old framework. Adapter layers bridge the two. Every developer needs to understand both frameworks and the translation layer between them. Onboarding time doubles. Bug investigations require tracing logic across framework boundaries. The build system accommodates both sets of dependencies, increasing bundle sizes and build times.

The longer a codebase stays in this hybrid state, the harder it becomes to complete the migration. New features get built in the new framework, but they sometimes need to interact with old-framework components, which means writing new adapter code. The adapter layer grows. The team loses track of which components have been migrated and which have not. Files that were partially migrated – using the new framework's syntax but still relying on old framework behaviours – create the most subtle bugs because they look migrated but are not fully migrated.

Traditional code quality tools cannot help with this problem. They can lint code for the old framework or the new framework, but they cannot identify the migration-specific patterns that cause issues: incomplete conversions, adapter complexity, and the interaction effects between old and new code. VibeRails uses AI reasoning to understand both frameworks and the specific challenges of the transition between them.

What VibeRails finds in migrating codebases

VibeRails scans every file in your codebase and identifies migration-specific debt that traditional tools miss entirely:

• Incomplete migration patterns – components that use the new framework's syntax but still import old framework utilities, files that were renamed to match new conventions but still contain old-framework logic internally, and modules where half the functions have been migrated and half have not
• Adapter complexity – bridge code that translates between old and new framework APIs, compatibility shims that have grown beyond their original scope, and wrapper components that add latency and make debugging harder by obscuring the actual call chain
• Test coverage gaps in migrated code – components that had test coverage in the old framework but lost it during migration, tests that still test old framework behaviour instead of new framework behaviour, and integration tests that pass because they test through adapter layers rather than testing the new code directly
• Configuration inconsistencies – build configurations that include both old and new framework plugins, environment variables used by both frameworks with different naming conventions, and deployment scripts that still reference old framework build outputs
• Dependency conflicts – old and new framework packages that pull in conflicting versions of shared dependencies, polyfills required for the old framework that interfere with the new framework's native implementations, and transitive dependencies that create version resolution warnings
• Performance regressions from compatibility layers – adapter code that re-renders unnecessarily, bridge layers that serialise and deserialise data at framework boundaries, and compatibility wrappers that prevent the new framework from applying its optimisations
• Dead migration scaffolding – temporary migration utilities that were meant to be removed after the transition, feature flags for gradual rollout that are now permanently enabled, and fallback paths to old framework code that will never execute

Each finding includes the affected files, the specific old-to-new pattern involved, and a severity rating that helps the team prioritise which migration gaps to close first. The structured report transforms an overwhelming migration into a manageable checklist.

When migration teams need a code review

Migration projects have specific inflection points where a full-codebase review prevents the most common failures:

Before declaring the migration complete. The team believes the migration is done, but scattered across the codebase are files that were not fully converted, adapter layers that were meant to be temporary, and tests that still exercise old framework code paths. A VibeRails scan provides an authoritative inventory of remaining migration work.

When the migration stalls. The team has migrated the easy parts and is now facing diminishing returns. A review quantifies exactly how much work remains and identifies which unmigrated components are blocking the most value – allowing the team to prioritise or make an informed decision about whether to complete the migration or live with the hybrid state.

After onboarding new team members. Engineers who joined after the migration started do not have the context of why certain patterns exist. They cannot distinguish between intentionally unmigrated code and accidentally incomplete migration. A structured review gives them a map of the codebase's migration state.

During planning for the next migration. Before starting a new framework migration, review how the previous one went. A VibeRails scan of the current codebase reveals how much debt the last migration left behind – informing the approach, timeline, and resource allocation for the next one.

Practical pricing for migration projects

Framework migrations already consume significant engineering resources. The tools used to support them should not add recurring costs on top:

• Flexible per-developer pricing – $19/month per developer (cancel anytime), or $299 lifetime per developer with one year of updates. Run scans as often as you need throughout the migration without worrying about usage limits.
• Free tier to evaluate – 5 issues per review at no cost. Run a scan on your codebase today and see the types of migration findings VibeRails produces before committing any budget.
• No CI integration needed – VibeRails runs as a desktop app. Point it at your local repository and run the scan. No GitHub App installation, no webhook configuration, no build pipeline modifications.
• BYOK model – VibeRails orchestrates the AI tools you already have (Claude Code or Codex CLI). If your team already uses these tools for development, VibeRails adds code review capabilities with no additional AI subscription cost.
• Repeatable scans – run VibeRails after each migration sprint to measure progress. Track the number of remaining migration issues over time and demonstrate measurable progress to stakeholders.

Desktop app, no vendor lock-in

VibeRails runs as a desktop app with a BYOK model. It orchestrates Claude Code or Codex CLI installations you already have. Your source code is read from disk locally and sent directly to the AI provider you configured – never to VibeRails servers. For teams in the middle of a sensitive migration, this means your codebase is not uploaded to a VibeRails cloud service at every stage of the transition.

Export findings as HTML for stakeholder presentations and migration planning sessions, or CSV for import into Linear, Jira, or whatever project management tool your team uses. The structured format means findings can be turned into actionable migration tickets with clear descriptions, file references, and priority ratings.

Start with the free tier today. Run a scan on your codebase and see what VibeRails finds. If the findings are valuable, upgrade to Pro at $19/month or $299 lifetime per developer.