What is the Strangler Fig Pattern?
The Strangler Fig Pattern is an incremental migration strategy where a new custom-code system gradually replaces a legacy Bubble.io application feature by feature — named after the strangler fig tree that slowly grows around and eventually replaces its host.
How It Works
Route Traffic
An API gateway or reverse proxy sits in front of both systems, directing requests to Bubble or the new app based on the feature.
Replace One Feature at a Time
Each migration cycle picks one workflow, page, or data type and rebuilds it in the new stack.
Validate Before Proceeding
The new feature runs in production alongside Bubble until it proves stable, then traffic shifts permanently.
Repeat Until Complete
The cycle continues until all features are migrated and Bubble can be decommissioned entirely.
When to Use It
- Complex Applications — Apps with dozens of workflows and data types that can't be rebuilt all at once without losing months of revenue.
- Zero-Downtime Requirement — Production apps where users can't tolerate a cutover window or a period of reduced functionality.
- Gradual Validation — Teams that want to prove the new stack works in production before committing to a full migration.
- Phased Budget — Organizations that need to spread migration costs across multiple quarters rather than funding a big-bang rewrite.
Implementation
- API Gateway Routing — Nginx, Cloudflare Workers, or a Next.js middleware layer routes requests based on path or feature flags.
- Shared Database — Both systems read from the same data store during transition, requiring careful schema compatibility.
- Feature Flags — LaunchDarkly or a simple environment variable controls which users see the new system during rollout.
- Data Sync Layer — A temporary sync service keeps Bubble and the new database consistent while both systems are live.
Advantages Over Big Bang Migration
- Lower Risk — Each feature migration is a small, reversible change rather than a single high-stakes cutover.
- Continuous Delivery — The new system ships value to users from day one instead of waiting months for a complete rewrite.
- Early Validation — Real user behavior in production reveals edge cases that no amount of staging testing would catch.
- Easier Rollback — If a migrated feature has issues, traffic routes back to Bubble instantly while the team fixes the problem.
Related Terms
Planning Your Strangler Fig Migration
Relis gives you the complete architecture map of your Bubble application — data types, workflows, API connectors, and privacy rules — so you can sequence your strangler fig migration intelligently, starting with the features that deliver the most value with the least complexity.