Monolithic frontends are great… until they’re not. As your app grows and your teams grow faster, tightly coupled single-page applications (SPAs) become bottlenecks — blocking release cycles, bloating your CI/CD pipeline, and making every change feel like defusing a bomb.

We faced this challenge and made a shift: moving from a centralized SPA to a micro frontend architecture that allowed independent development, secure integration, and long-term scalability. Here’s how we approached it.

The Problem

With multiple teams contributing to a shared frontend, we started seeing real issues:
• Regression risk on every merge
• Feature teams stepping on each other’s toes
• Difficult onboarding and slower innovation
• Security logic duplicated across modules

We needed a way to decouple our frontend — but without breaking user experience or introducing performance penalties.

The Architecture: Host + Feature Modules

We built around a host shell that dynamically loads standalone feature modules. Each feature app (micro frontend) is independently built and deployed.

Host responsibilities:
• Routing & layout
• Shared UI components
• Secure session management
• Loading feature modules via custom elements or dynamic imports

Feature module responsibilities:
• Own business logic & UI
• Operate independently (separate repo, pipeline, ownership)
• Integrate with host APIs and event systems

This separation allowed true autonomy without giving up consistency.

Security & Session Design

Session handling across isolated modules is tricky. Our approach included:
• Central session validation handled by the host
• Controlled sharing of session metadata with feature modules
• Use of lightweight client identifiers to improve trust and traceability
• Feature modules validating session presence before sending requests

This kept our architecture stateless on the client while preserving secure flows across boundaries.

Deployment Setup

Each feature app had:
• Its own Git repo
• Its own CI/CD pipeline
• Static hosting (S3, Nginx, etc.)

The host maintained a manifest (think plugin registry) and loaded modules based on role, route, or config.

Result: One team’s delay or rollback didn’t affect the rest of the platform.

What Worked Well 

• Faster releases with isolated risk
• Feature teams could work independently and scale horizontally
• Secure, stateless sessions that didn’t rely on sticky behavior
• Unified experience for users even across separately deployed modules




Lessons Learned


• Define contracts early (event APIs, auth flows)
• Fail gracefully when a module doesn’t load
• Avoid unnecessary sharing — lean into isolation




Wrapping Up

Micro frontends aren’t a silver bullet — but they’re a great way to scale large frontends while keeping teams and features loosely coupled.

If you’re thinking of going modular, start small. A shared shell + 1-2 feature apps is a good place to experiment.

I would love to hear how others are handling session security or deployment in distributed frontends. Let’s connect!