System context
The project focused on building a dedicated operational frontend for internal teams working with a larger, distributed system.
The application acts as a single-page interface for day-to-day operational tasks such as:
- managing staff members and their roles,
- browsing and inspecting service points,
- viewing operational status and assignments,
- interacting with data exposed by backend systems through a dedicated BFF layer designed and implemented as part of the project.
The system was designed from the start as:
- an internal tool, not a public-facing application,
- a long-lived operational interface,
- a frontend that must remain predictable, secure, and evolvable over time.
Core challenges
1. Frontend as an operational system, not just UI
The application is not a “thin UI layer”.
It is responsible for:
- enforcing access boundaries before data is shown,
- presenting role-aware views and actions,
- handling authentication state and session lifecycle,
- surfacing operational status clearly and consistently.
This required treating the frontend as a first-class system component, not just a rendering layer.
2. Multiple roles, shared interface
Different user groups operate within the same application, including:
- operational staff,
- managers and coordinators,
- technical or administrative users.
Each role:
- sees different data,
- has access to different actions,
- works in a different operational context.
The challenge was to design:
- a clear role-based access model,
- predictable navigation boundaries,
- a UI that remains understandable even as responsibilities differ.
3. Secure and predictable backend integration
The SPA communicates with backend systems via a BFF (Backend-for-Frontend) API.
Key requirements included:
- secure authentication via an external identity provider,
- safe token handling on the client side,
- consistent error handling and recovery,
- zero leakage of authentication data to third-party origins.
The frontend had to remain contract-agnostic while still enforcing strong operational guarantees.
The BFF was treated as a first-class component of the frontend architecture, designed and implemented alongside the SPA to provide stable contracts and isolate backend complexity.
4. Long-term evolution under active use
The application is actively evolving.
From the beginning, it had to support:
- incremental feature delivery,
- architectural changes without rewrites,
- partial functionality without breaking existing flows.
This required:
- strong architectural boundaries,
- minimal coupling between feature areas,
- explicit handling of “work-in-progress” areas.
Architectural approach
A key decision was to design the SPA as a layered frontend system, not a monolithic UI.
High-level structure:
- Application shell – global providers, routing, layout, and error handling.
- Routing and guards – navigation structure and access enforcement.
- Feature areas – isolated UI domains responsible for view composition.
- Cross-cutting services – authentication, theming, localization.
- HTTP pipeline – token attachment, retry logic, and error propagation.
This approach:
- keeps responsibilities explicit,
- allows features to evolve independently,
- makes the system understandable without code-level knowledge.
Operational views and workflows
The current version of the application already supports several operational workflows.
Staff management
- role-aware staff listing,
- detailed staff profiles,
- visibility of roles, areas, and notification preferences,
- clear operational status indicators.
Service point management
- listing of service points with operational state,
- detailed views combining address, services, and coordinates,
- status visibility and assignment context.
UI showcase
UI screenshots shown with anonymized data and removed branding.
Backend communication model
The frontend integrates with backend systems using:
- REST over HTTP with JSON payloads,
- same-origin API paths exposed by a BFF layer,
- a dedicated BFF layer designed and implemented together with the SPA,
- OAuth2 / OpenID Connect authentication (Authorization Code + PKCE).
Key characteristics:
- authentication state is managed centrally,
- tokens are stored in memory and attached via HTTP interceptors,
- 401 responses trigger a controlled retry and fallback to login,
- 403 responses route to access-denied views,
- backend errors are surfaced as explicit UI states.
UI components remain decoupled from API details, relying on a centralized integration layer.
The BFF is responsible for shaping backend responses into frontend-oriented contracts and enforcing consistency across multiple backend systems.
State management and reliability
The application uses:
- lightweight local state within components,
- shared state via dedicated services,
- Angular Signals for synchronous UI state,
- RxJS for asynchronous flows.
Reliability patterns include:
- single-retry guards for authentication failures,
- explicit prevention of retry loops,
- predictable loading and error states.
The frontend does not embed business rules or domain workflows beyond access control.
Current state and evolution
This application is actively evolving.
Not all planned features are implemented yet, and some areas are intentionally minimal. This is a deliberate choice:
- functionality is added incrementally,
- architectural boundaries are established early,
- unfinished areas do not compromise system stability.
The case study reflects a real production trajectory, not a polished demo snapshot.
Final outcome (so far)
The result is a solid operational SPA foundation that:
- supports role-based internal workflows,
- enforces access and security at the UI level,
- integrates cleanly with backend systems,
- remains understandable and evolvable as features grow.
The project demonstrates how a frontend application can be designed as a long-term operational system, even while still under active development.
Architecture showcase (GitHub)
This case study focuses on context, challenges, and outcomes.
For a deeper look at:
- frontend architecture,
- execution flows,
- integration patterns,
- and engineering trade-offs,
see the dedicated architecture showcase repository:
👉 https://github.com/rocketdeploy-dev/showcase-internal-operational-spa