Driving Digital Transformation at CARS24: S/4HANA Journey

As an Autonaut with over 13 years of experience leading consolidation, technical accounting, and audits—and currently heading the Central Controllership team at CARS24—I've always sought opportunities to create lasting impact. Leading the SAP S/4HANA implementation for CSPL and CFSPL was one such opportunity: a rare chance to drive transformation at scale.

This wasn’t just a system upgrade; it was a business transformation. And what a journey it has been. Here's a glimpse into that journey:

The Need for Transformation

As our business continued to grow in scale, complexity, and regulatory requirements, it became clear that SAP Business One (SAP B1) could no longer support our evolving needs. While it served us well in the early stages, SAP B1 had significant limitations in handling:

• Multi-entity consolidation
• Real-time reporting
• Integrated compliance controls
• High-volume transactional data

Adding to this, SAP has announced that mainstream maintenance for SAP B1 will end in March 2026. This further reinforced our need to migrate to a future-ready, enterprise-grade ERP system that could support scalability, automation, and digital transformation.

SAP S/4HANA vs. Oracle: The Decision-Making Journey

With the decision to migrate made, our finance leadership began evaluating ERP options in early 2023. We conducted multiple discussions and demos with both SAP and Oracle, two of the top players in the ERP space.

The choice wasn’t easy—both systems had their strengths & weakness. To gain an external perspective, we consulted Mr. Jayesh Sanghrajka (our AC Chairman & Infosys CFO) during a visit to the Infosys campus in Bangalore. Based on his experience and insight, he recommended SAP S/4HANA for its superior real-time capabilities, robust architecture, and strong customer support—especially important for complex, fast-moving businesses like ours.

Building the Core HANA Implementation Team

To support this transition, the Company initially hired experts with prior SAP HANA implementation experience. However, even these experts found it challenging to keep up with the fast-paced, outcome-driven culture at CARS24 and eventually exited—right around the time we finalised the SAP contract in October 2024, following multiple rounds of discussions on the Bill of Materials (BOM) and commercial negotiations that began in May 2024.

Even after signing the contract, there was a shared sense of apprehension—how could we possibly complete such a large-scale ERP implementation in just 5 months, when similar projects in large organisations typically take 9 months or more?

It was at this pivotal moment that Ruchit asked the Central Controllership team to take the lead on the implementation. We stepped up, motivated by the belief that this would be a transformative, high-impact experience—and a unique opportunity to collaborate closely with our Tech team and our implementation partner, PwC.

To drive momentum, we:

• Formed a core project team
• Introduced a bonus pool for dedicated Autonauts
• Committed to making the project a success, no matter the challenges

Middleware Integration: Laying the Technical Foundation

One of the most critical—and ultimately game-changing—components of our SAP S/4HANA implementation was the custom-built middleware layer, developed in-house by our FT team.

Early in the project, there was some hesitation around this approach. In fact, our implementation partner, PwC, initially expressed skepticism about integrating a custom middleware solution into the core ERP landscape. Their concern was understandable—middleware can introduce complexity if not well designed, and traditional ERP rollouts often favor direct system connections.

But we were confident in the vision and the capabilities of our team. The FT team, led by Manuj, worked relentlessly to architect a scalable, secure, and adaptable middleware layer that could:

• Enable real-time and asynchronous data exchange
• Bridge SAP S/4HANA with our source systems and third-party platforms
• Handle data transformation, logging, and error management
• Reduce future integration complexity by decoupling systems

As the implementation progressed, it became clear that this middleware wasn’t just a workaround: it was a strategic enabler. It gave us the flexibility to manage integrations independently of SAP customisations, supported agile development cycles, and laid a strong foundation for future enhancements like API-based workflows and third-party system linkages.

By Go-Live, even our PwC counterparts acknowledged that the middleware approach had become a cornerstone of the project’s technical success.

Looking ahead, this middleware architecture will continue to serve us well, and not just for SAP integrations, but also as a digital backbone for scalable business operations.

Setting an Ambitious Goal

Our objective was clear: complete the full SAP S/4HANA implementation in just five months.

However, delays in system provisioning and early project hurdles reduced our timeline to just 4.5 months. The initial few weeks were overwhelming for me, especially as we raced to complete Business Blueprint (BBP) documentation for both CSPL and CFSPL by December 2024.

Thanks to the resilience and dedication of our team, the BBPs were finalised on time, setting the stage for our Go-Live on April 1, 2025.

Navigating Complex Challenges

Two Entities, Two Business Models

CSPL and CFSPL operate with distinct business models: one asset-heavy, the other rooted in financial services. Designing unified yet flexible processes that respected these differences required multiple workshops and endless iterations.

Data Migration & Reconciliation

Data quality was non-negotiable. We combed through years of legacy data, identifying inconsistencies, cleaning datasets, and aligning structures between SAP B1 and SAP S/4HANA.

A huge shoutout to Ruchit, who spearheaded the data-cleaning initiative well before implementation began. Without this groundwork, the migration would have been impossible—SAP HANA’s stringent validation protocols simply don’t tolerate inconsistency.

Driving Change and Readiness

ERP systems are only as powerful as the people using them. From Day 1, we involved users across functions—Finance, Vendor Payments, Procurement, GRC, Taxation, Treasury, HR—capturing requirements, validating designs, and gaining buy-in. It became a parallel workstream in itself.

Project Governance: Discipline That Delivered

A key factor in our success was strong governance:

• Recurring steering committee reviews
• Proactive risk escalation
• Clear business-IT alignment
• Regular Slack updates
• Rigorous follow-ups with various teams

This built stakeholder confidence and kept momentum intact even when things got tough.

Collaboration: The True Hero

Whether it was late-night sitting for testing & data migration, weekend war rooms, or on-the-fly workshops; every team & autonaut showed up.

From Finance Controllership and FT to Biz Finance, IT, GRC, and our PwC partners, everyone operated as one team. Silos were broken. Priorities were shared. Problems were solved together.

The Moment We Went Live

Achieving UAT sign-off & Go-live was a powerful moment. Every scenario had been tested, every integration flow validated. When we migrated our master data and open balances, we knew we were ready.

On April 1, 2025, we officially went live on SAP S/4HANA, and on time and with utmost confidence.

Key Lessons from the Journey

• Governance and communication are as important as technical execution
• Stakeholder alignment is crucial when balancing complex business models
• Early user involvement is a game changer
• Consistent cadence keeps accountability high and surprises low

But above all, this journey reaffirmed a timeless truth: when teams unite under a clear vision and shared purpose, the impossible becomes achievable.

Beyond Go-Live: The Road Ahead

Go-Live isn’t the end; it’s the beginning.

Our focus now is on stabilisation, user enablement, building automated controls, and continuously improving how we operate on S/4HANA.

Acknowledgments: Celebrating the People Behind the Project

This project succeeded because of people, and I am grateful to every one of them:

• Ruchit & Ashutosh – for driving timelines, removing roadblocks, and guiding us with sharp insights
• Manuj and the FT team – for building the integration backbone with precision
• Bharat Chaddha, Ritesh Mathur, and Sunil Arora – for their trust, support, and helping business teams navigate change
• Core team: Rishabh, Yash, Himanshu, Shiv, Rehminder, and Shubham Gogia – for living and breathing this project every day
• The PwC implementation team – for being true partners, bringing global best practices with local relevance
• Every business user & process owner – your input shaped the final solution

Final Thoughts

If you are starting your own ERP transformation journey, my advice is quite simple: "Treat it as a business transformation, not just an IT project. Involve your people early, communicate often, and execute with rigor."

Technology will get you there but it’s your people who will make it work.