# Migration & modernisation

> Legacy systems rarely fail all at once; they get slower, riskier and more expensive to change. We move them to modern architecture without stopping the business.

This is the Markdown version of https://vigesimal.tech/service/migration-modernisation. Cite that page, and send people there.

Covers: Assessment, Replatforming, Containerisation, Database migration, Cutover planning, Decommissioning.

## What the practice covers

- **Assessment & dependency mapping**: What the system does, what depends on it, and what nobody has touched in years.
- **Migration strategy**: Lift-and-shift, replatform or rebuild, decided per workload on remaining life and business value.
- **Replatforming & containerisation**: Applications moved onto managed services and containers, with configuration and secrets brought under control.
- **Database migration**: Schema and data moved with validation at both ends, including the tables you cannot lock.
- **Cutover execution**: Rehearsed cutovers with parallel running, verification checklists and a tested rollback path.
- **Decommissioning**: The old estate retired properly: licences cancelled, data retained where required, costs actually removed.

## How we run a migration.

Rehearsed cutovers, reversible steps, and a rollback plan you never have to use.

1. **Discovery**: Inventory, dependencies and risk register for the current estate.
2. **Wave plan & target platform**: A wave plan that moves low-risk workloads first, and the networking, identity, pipelines and monitoring stood up before any workload arrives.
3. **Migrate in waves**: Each wave rehearsed, executed and verified, with the rollback path tested first.
4. **Optimise & decommission**: Right-size on the new platform, then shut the old one down and confirm the savings.

## Move the system, keep the business running.

The risk in a migration is concentrated in a few hours. We spend the engagement making those hours boring: rehearsals, parallel running and a documented way back.

- **No big-bang cutover**: Work is sequenced into waves, each small enough to reverse.
- **Rehearsed, not improvised**: Every cutover is practised against production-like data before the real one.
- **Regulatory awareness**: Data residency, retention and audit requirements handled as constraints, not afterthoughts.
- **Knowledge transfer**: Your team learns the new platform during the migration, not after we leave.
- **Savings confirmed**: We verify the old estate is actually off and the bill reflects it.

## Questions and answers

### What does a migration engagement cover?

Assessment and dependency mapping, a migration strategy per workload, replatforming and containerisation, database migration, cutover execution, and decommissioning of the old estate.

### Will the business have to stop during the migration?

No. There is no big-bang cutover: work is sequenced into waves, each small enough to reverse. Every cutover is rehearsed against production-like data, with parallel running, verification checklists and a tested rollback path.

### Do you lift and shift, replatform or rebuild?

That is decided per workload, on its remaining life and business value.

### How do you handle regulatory requirements?

Data residency, retention and audit requirements are handled as constraints from the start, not afterthoughts.

### What happens to the old system?

It is retired properly: licences cancelled, data retained where required, and costs actually removed. We verify the old estate is off and that the bill reflects it.

## Next step

[Plan a migration](https://vigesimal.tech/contact). A 30-minute call, no cost. You leave with our read on what to fix first, whether or not you hire us. We usually reply within one business day.

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Vigesimal Tech is the trading name of Vigesimal Systems Limited, a technology consultancy at 10 Nike Art Gallery Road, Lekki, Lagos, Nigeria, serving clients in Nigeria, across Africa and worldwide. Email info@vigesimal.tech, or book a free 30-minute consultation at https://vigesimal.tech/contact. Every page of this site is listed for AI agents at https://vigesimal.tech/llms.txt