Building Modern SaaS Products on SAP BTP: Why the Shift is Harder (and Better) Than It Looks

Disclaimer: This article was inspired by SAP’s work on modern cloud development—particularly the blog “How SAP’s ABAP Cloud Partner Reference App simplifies multi-tenant side-by-side extensions”—and aims to explore these architectural topics further.

SAP is undergoing its largest transformation in decades — moving from on-premise monoliths to cloud-native architecture.
Products like Datasphere, Analytics Cloud, and Business Data Cloud exist only in the cloud. Yet despite this shift, many software vendors still treat SAP as if it’s 2010.

Let’s unpack why this gap represents a huge opportunity for disruption—and why mastering SAP Business Technology Platform (BTP) is far more complex than marketing suggests.

🧱 The Architectural Divide: From Monolith to Node

To understand BTP’s challenge, we must first recognize how drastically enterprise architecture has evolved.

The Old World: SAP as the Center of Gravity

For decades, SAP ECC was the heart of enterprise data.
Every surrounding system—CRM, warehouse, custom apps—fed into this monolithic core.

External Systems → SAP ECC Monolith → Single Source of Truth

This model made SAP integration deceptively straightforward:

Write ABAP code directly inside SAP.
Deploy via Transport Requests.
Access everything natively—tables, function modules, transaction control.

Many of these ABAP-built solutions were technically brilliant and lightning-fast.
But here’s the catch: most ABAP vendors struggle to build true cloud-native products on BTP.

The New Reality: S/4HANA as Just Another Node

In today’s distributed architecture, S/4HANA is one of many systems—not the core gravitational force.
It now coexists with Salesforce, Workday, and SAP’s own cloud services, all linked through SAP BTP as the integration and extension layer.

This forces a complete redesign of how we build SaaS solutions for the SAP ecosystem.

☁️ The BTP Reality: Why It’s Harder Than It Looks

The challenge lies in bridging the ABAP world’s deep system access with the modern cloud’s strict boundaries.

What You Lose: The ABAP Advantage

When you build in classic ABAP, you enjoy:

Full access to SAP objects and processes
Consistent integration via BAPIs and function modules
Transactional control
30+ years of accumulated frameworks and patterns

What You’re Limited To: The BTP Model

On SAP BTP, you can only use officially exposed interfaces:

REST/OData APIs (when available)
RFC/Web Services (legacy “sidecar” approach)
Custom ABAP extensions (when APIs are missing)

💡 SAP API Business Hub explore API coverage.

The truth is that many SAP modules lack full API coverage.
Before writing a single line of code, you need to map your use cases to existing APIs.

🚀 Why Build SaaS on BTP Anyway?

Despite the technical limitations, the strategic advantages are too significant to ignore.
BTP is not just a platform—it’s the enforcer of SAP’s Clean Core strategy.

Strategic Advantage	Why It Matters
Leverage SAP Objects Without Core Modification	Extend SAP entities using CAP (Node.js/Java) or RAP (ABAP RESTful). Stay compliant with Clean Core.
Instant User Management & Security	XSUAA provides built-in SSO and user provisioning—huge time saver.
Multitenancy for Customer Extensions	One product, multiple tenants. Separate data, shared logic.
Modern Deployment & CI/CD	Global scalability, no hardware costs, one-click updates.

🧩 Two Strategic Approaches to Building SaaS on BTP

1. Extend SAP Objects (Tight Coupling)

Best for: Enhancing existing SAP processes (analytics, compliance, industry workflows)
Tech focus: CAP/RAP extensions tied to standard SAP entities

2. Build Independent, Integrate Loosely (Decoupled Model)

Best for: Standalone apps that integrate with SAP for master or transactional data
Tech focus: Integration Suite + Event Mesh for asynchronous data flow

⚠️ Common Pitfalls on the BTP Journey

1. The “API Gap Surprise”

Teams assume all needed APIs exist—only to find critical workflows missing.
They then add custom ABAP in the S/4HANA core, creating a sidecar dependency.

Lesson: Always verify API coverage early.

2. The Custom Integration Trap

Each customer ends up with a unique integration setup—five customers, five versions, zero reusability.

Lesson: Design for productization, not just project success.

3. Deployment Complexity

If each installation requires weeks of SAP consulting, your SaaS model doesn’t scale.

Lesson: Simplify setup. Automate provisioning and configuration.