There’s a better way to modernize pharmacy benefits management systems. Enter vertical slice architecture —a modern approach to software design that enables PBMs to transform their technology, launch new products and features faster, and deliver substantial business value.
For PBMs looking to modernize, vertical slice architecture can be a game-changer. It empowers teams to work independently, deploy faster, and respond to market demands without getting bogged down by legacy complexity.
In this article, we’ll dive into what vertical slice architecture is, why it’s more effective than traditional approaches like onion architecture, and how it can help PBM companies achieve true agility. We’ll also discuss what engineering teams need to know before adopting this architecture and provide practical steps for getting started, ensuring your organization is ready for its next big leap forward.
Vertical slice architecture organizes software by business requests, not technical layers. Imagine an architecture where software is organized around distinct business requests, not constrained by the traditional boundaries of layered architectures like n-tier or hexagonal structures. In this model, each "slice" is a self-contained unit that handles everything required to fulfill a specific request—from front-end interactions to database operations.
This contrasts with architectures like the onion architecture, which organizes code into rigid horizontal layers (e.g., UI, services, and data access layers). Instead of layering components, vertical slices couple functionality along the axis of change. Imagine needing to add or modify a feature. In a traditional layered approach, this might involve adjusting multiple components across different layers—tweaking the UI, altering model fields, refining validation logic, and so on. But with vertical slices, all these changes are contained within a single slice, minimizing impact on other parts of the system.
This approach offers several advantages. It eliminates the need for common abstractions like shared services or repositories often necessary in layered designs. While some shared elements might still be required due to tooling constraints, the goal is to minimize cross-slice logic sharing. Each slice is free to independently determine the best way to fulfill its request, making the system more flexible and easier to adapt as business needs evolve.
Monolithic structure: The onion architecture is built around concentric layers—UI, services, and data access—requiring developers to navigate through these layers for every change. This results in low cohesion, leading to a high learning curve as developers adhere to the law of demeter to achieve reusable code.
Dependency-heavy: It enforces strict separation of concerns, often leading to unnecessary abstractions (e.g., controllers that must talk to services, which then must talk to repositories). This rigidity increases complexity and slows down time-to-market.
High regression testing: Changing any business logic can have ripple effects across layers, increasing regression testing efforts and maintenance overhead.
Feature-driven: Organizes functionality by business use cases or requests, ensuring all the code related to a specific feature is contained within a single slice. This reduces interdependencies, allowing changes to be made without affecting other parts of the system.
Domain-Driven Design (DDD) and CQRS-friendly: Vertical slices align well with techniques like Domain-Driven Design and Command Query Responsibility Segregation (CQRS). Each slice can encapsulate its own domain logic, keeping commands (actions that change state) separate from queries (actions that fetch data).
Scalable and agile: Since slices are self-contained, they can be developed, tested, and deployed independently, reducing deployment cycles and enabling faster response to market changes.
For PBMs, modernizing technology systems can be daunting. Most PBMs are burdened by legacy platforms that were never designed for today’s business needs. Here’s how vertical slice architecture can unlock significant benefits:
1. Accelerate Time-to-Market for New Products and Features: In the PBM space, speed is critical for adapting to changing regulatory requirements or launching market-leading features. Vertical slices enable quicker development cycles since each slice is isolated and independent.
Real-World Example: A PBM looking to launch a new plan configuration portal could develop a feature that enables the plan administrator to duplicate a previous plan as a separate vertical slice. This allows changes to be made to that feature without disrupting the entire plan configuration system. By isolating this feature, PBMs can quickly roll out updates based on customer feedback or regulatory requirements without affecting other parts of the system.
2. Reduce Complexity and Technical Debt: Many PBMs struggle with technical debt from decades-old systems. Vertical slice architecture allows for incremental modernization by isolating and refactoring business capabilities one slice at a time. This reduces risk and makes the modernization journey manageable.
3. Improve Agility and Scalability: PBMs face constant shifts in customer expectations and regulatory changes. Vertical slice architecture enables rapid adaptation by focusing development efforts on the areas with the highest business impact, such as plan configuration or claims automation.
4. Enhance Customer Experience: PBMs can isolate customer-facing features into their own slices, making it easier to personalize user experiences. This allows for rapid experimentation and tailored services without overhauling the entire system.
While the benefits are compelling, a successful transition to vertical slice architecture requires alignment between engineering teams and business stakeholders. Here are key considerations:
At Praxent, we understand the unique challenges PBM companies face when modernizing their technology. Our team of senior enterprise architects has extensive experience guiding PBMs through digital transformations. By leveraging vertical slice architecture and other modern architecture practices, we help you:
Accelerate product launches by breaking down monolithic systems into agile, independent slices.Vertical slice architecture is an ideal approach for PBM companies seeking to modernize their technology stack while maintaining agility and delivering customer value. By embracing this architecture, PBMs can reduce complexity, accelerate product development, and better align technology with their business goals.
Praxent is here to guide your organization through this transformation, ensuring your systems are built to adapt to the ever-changing PBM industry. Contact us today to get started on your modernization journey.