How Alibaba Migrated 1,600 Node.js Apps to Serverless: Lessons and Strategies

Current Situation

Alibaba has over 1,600 Node.js applications, many of which are low‑load BFF services that waste resources and are hard to govern due to inactive maintainers.

Traditional development processes are lengthy, requiring budget and resource approvals.

Front‑End Development Upgrade

The upgrade aims at two goals: "front‑end empowerment"—breaking technical barriers to reach data‑centric layers, and "front‑end efficiency"—leveraging Serverless to lower development thresholds, reduce labor costs, and enable rapid, small‑step delivery.

Benefits

Since October, Alibaba migrated the Taobao and Fliggy recommendation pipelines to Serverless, handling tens of millions of requests and achieving cost reductions of 40‑70% depending on traffic peaks.

Serverless also cuts operational overhead, simplifies code, and consolidates runtime governance to a single version.

Thoughts

Two migration approaches are offered: (1) refactor using FaaS + BaaS for a cleaner codebase, or (2) wrap an entire traditional app as a single function for quicker migration.

Serverless is broader than FaaS; it represents a fine‑grained deployment model that responds to user demands.

Migration Details

Traditional services (HTTP, scheduled tasks, RPC) are extracted as separate entry points and transformed into event‑driven functions based on the capabilities of platforms like Alibaba Cloud FC.

Packaging mechanisms allow shared logic across environments, though function size limits can pose challenges.

Proxy Mode

The original web app remains, with its logic layer moved to cloud functions while the HTTP gateway handles routing.

Gateway Mode

All code migrates to functions; the HTTP gateway manages routing, sessions, and authentication, leaving functions to focus on business logic.

Masquerader Mode

Wrap the entire web server in a function, forwarding requests to a fixed port and converting responses back, suitable only for stateless, single‑process applications.

Conclusion

The presentation shares Alibaba's practical experience from 2022‑2023 in upgrading development models and migrating legacy applications to Serverless, highlighting both technical solutions and organizational impacts.