How to achieve Tech Transformation in less than 18 months

Why: Opening the IT Black Box

For most CEOs, the relationship with IT follows a familiar and frustrating pattern. A new CIO is brought in with high expectations, only to disappear into a lengthy discovery phase where critical knowledge becomes concentrated in a single person. Communication with business sponsors breaks down, priorities drift, and a quiet but corrosive mistrust begins to take hold. Meanwhile, IT remains what it has always been: business-critical, cost-heavy, and structurally complex.

The consequences compound quietly. IT costs creep upward through under-used licenses and tools no one has fully mapped, while the business impact rarely keeps pace - producing a growing misalignment between what IT consumes and what the business receives. Tools deployed at great expense often generate more frustration than perceived gains. The gap widens between Tech teams (IT, Data, Digital) and the business

Our method: Opening the black box in 10 weeks

Senior blended squad (Strategy consultants + Tier 1 Tech experts) to run a fact-based diagnostic - align ExCom, business sponsors and IT leadership - and be ready for arbitrage.

• Business deep-dive: pain points mapped across functions, use cases prioritised, value pools sized
• Tech audit: application portfolio reviewed, architecture, data foundation, cyber posture, vendor and sovereignty exposure; cost base benchmarked against sector standards
• AI readiness scored on data, governance and infrastructure

This blended setup does three things at once: it puts strategic clarity, technical credibility and operator's pragmatism in the same room ; it forces alignment between business and IT from day one ; and it enables collective onboarding so that internal teams own the result by the end.

How: Escape the Everest North Face syndrome

When the climb looks too steep, paralysis sets in. Many organizations recognize the need to change - and then simply can’t address it. Risks, budgets and efforts feel too high; the starting point is unclear, and the target even more so.

The analogy to high-altitude mountaineering is apt. Reaching 8,000 meters is never achieved in a single push from base camp. Transformation works the same way. The organizations that succeed are those that design the journey in stages and secure early wins that build confidence.

And one decisive thing has changed: AI. What took 24 to 36 months three years ago is now within reach in 12 to 18. AI compresses the climb across four layers:

• Analysis: interview synthesis, application portfolio audit, requirements extraction…
• Engineering: agentic coding ships MVPs, dashboards and integrations in days; legacy code refactored, tests generated, deployments automated
• Data: AI agents for cleansing, reconciliation and harmonization, auto- lineage and documentation
• Steering: auto-generated status reports, risk detection, comitology briefs, communications and training - Program teams focus on arbitrage, not assembly

Our method: A 12 to 18-month transformation program, designed to deliver and to be handed back

• A structured Transformation Program: 20 to 40 initiatives sequenced to close the gap between as-is and target, each with case-for-change, sizing, owners and KPIs
• Co-led with Business & Tech ExCom sponsors: one steering, one set of priorities, fast arbitrages, rituals defined from day one
• Blended squads on every critical workstream: client teams side by side with Tier 1 Constellations experts (strategy + architecture, data, cyber, cloud, AI)
• An active Transformation Office: paces delivery, lifts blockers, plans reversibility from day one. The engine room of the program, not a PMO that tracks slides

What: The Two-Train approach

The Two-Train approach is how we ensure transformation delivers impact early, without compromising on the depth of the change. Train 1 carries the foundations and the first business wins. Train 2 carries the industrialisation, the operating model, the scaling.

The business does not have to wait for Train 2 to start receiving value. Train 1 lands first - and what it brings funds, legitimises and accelerates the rest.

3 dimensions are to be addressed jointly

Data Foundation

Clean, governed and integrated data on a platform that connects ERP, CRM, operations and finance systems - the technical backbone on which everything else runs, cleaned with the business and governed to stay that way.

IS Unlocked

Legacy systems rationalized, application portfolio reduced, architecture modernized, cyber posture upgraded, sovereignty arbitrages made. The blockers cleared so business and AI ambitions can execute.

AI Acceleration

A factory to shape, prioritise and ship use cases. Agents, analytics and AI products embedded in core processes, with ROI tracked end-to-end.

Our method: 360° tech, addressed pragmatically and end-to-end

• A pragmatic roadmap with short-term wins: the Two-Train approach ensures the business does not have to wait for the full program to receive value.
• Built to be handed back: exit rights in every contract, reversibility designed from day one.
• Tier 1 experts across the full stack: AI, Data, Cyber, IS, Cloud - on the ground, hands-on, accountable.
• AI-native methods: agentic coding as standard, AI-augmented consultants, reusable assets (in-house AI stack, Lazy Data Platform, Infrastructure as Code) that cut time-to-value by 2 to 3x.

[Image: infographic “The Two-Train Approach in a Tech Transformation” – timeline version]

[Image: infographic “The Two-Train Approach in a Tech Transformation” – illustrated version]

Client story: From 11 build-ups to one performance engine

A European Telco leader

Starting point. A European leader in fiber infrastructure had completed 11 acquisitions in three years. The legacy was heavy: 300+ applications, multiple overlapping ERPs, fragmented data, no Data governance, and the recent departure of the CIO. The company was operating under LBO pressure, with a clear obligation to deliver visible performance gains fast.

The program. An 18-month transformation. The target architecture defined, gap analyses run, around 30 initiatives structured across 12 parallel workstreams. A Transformation Office set up and run for 14 months at COMEX level, with rituals for business and tech sponsors. Tier 1 experts deployed (ex EY-Parthenon, ex C-Level OVH, ex Capgemini, ex Artefact). A new IT organisation built from scratch. Reversibility planned from day one.

Outcomes - first station (Train 1)

• Solid Data Foundation: data quality (cleaning + governance) and data technology (platform + interfaces) in production.
• PMI mostly delivered: CRM live across 80,000+ accounts, ERP migrations executed with handover on the remaining ones, invoicing harmonised.
• First Data Platform activations, including the Revenue Assurance AI use case - which we initiated and which has already generated several million euros of P&L impact.

Outcomes - full performance (Train 2)

• A functional IT organisation with the Target Operating Model adopted.
• Data Office and governance fully transferred to internal teams.
• Use-Case Factory active, with AI agents in production on support and quoting.
• Full reversibility achieved in Q2 2026. Constellations stepped back into a light advisory role.

“We didn’t want another 5-year IT master plan. We wanted to decide, prioritise, and see concrete results - fast. The Constellations team delivered the change, then handed us back the engine.” - Client CEO

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