Platform Modernisation in Regulated Public Transit

Context

A public transit organisation operating a grown, product- and SAP-bound customer management and eTicketing system. Expensive to run, hard to integrate, and wired to ERP, CRM, billing and reporting through point-to-point connections. Replacing it touches a regulated environment with interoperability obligations — and leaves no room for a big-bang cutover.

Challenge

Define a realistic path off the legacy system without losing eTicketing interoperability, breaching public-sector compliance requirements, or trading one vendor dependency for another. In parallel, manual and time-consuming sales and contract processes needed to become digital and self-service capable.

My Role

Technical advisor and solution architect, across four lines of work:

Making technology decisions. Market survey of certified background systems and assessment of off-the-shelf product, cooperation with another transit operator, and custom build. The result was a decision basis with a reasoned recommendation, not a list of options.

Developing the platform vision. Consolidation of a grown process landscape from over a hundred current-state processes down to fewer than fifty target processes across specialised building blocks. The target platform was cut into clearly owned zones, with the separation of contractual and online identity as a load-bearing model.

Making systems talk to each other. Design of an event-driven target architecture with a central integration layer: systems publish business events once, others subscribe without knowing each other. The binding event format is the vendor-neutral CloudEvents 1.0 standard, keeping the exit path open without a schema break. Alongside it, an event catalogue with a reasoned connection order and a security-assessed, one-way network crossing for the critical-infrastructure context.

Convincing stakeholders. Preparation as a decision paper with four load-bearing arguments, an investment estimate with its confidence level stated, and lines of reasoning per governance body. I presented and defended the concept before those bodies. Regulatory requirements — eTicketing standards, data protection, IT security — were translated into concrete architecture and selection criteria.

Outcome

Decision basis and event-driven target architecture delivered. The replacement is designed as a controlled, incremental path rather than a single cutover. The integration layer establishes vendor-neutral interoperability and turns connecting a new system into a configuration task rather than a project. Architecture, event catalogue and technology assessment remain as a reusable blueprint — answering the integration question that resurfaces with every system replacement.