“Distil Stack demonstrated a strong understanding of the complexity behind a specialized medical education platform. They helped bring together question banks, assessments, resident programmes, rankings, and performance tracking into a cohesive learning system.”
Application Modernisation
Legacy application modernization services
We move legacy applications to modern architecture in controlled phases, so you cut technical debt, open the door to AI and keep operations running throughout.
A custom engineering engagement
We scope this service around your workflow, existing systems and acceptance criteria. The work starts with the problem and its constraints, then a written scope and price. A packaged solution is a different buying route: choose it when its defined deliverables already fit the job.
01The problem
Where things usually stall
Legacy systems rebuilt or re-platformed in phases, without stopping the business.
- 01
Every change takes months
A small feature touches ten tightly coupled modules and needs a full regression cycle.
- 02
Skills you can't hire for
The system depends on frameworks and people that get harder to find every year.
- 03
Data locked away
Valuable records sit in a database no modern tool or AI model can reach.
02Capabilities
What we deliver
- 01
Legacy assessment
Code, architecture, data and dependency analysis with a clear view of risk and cost.
- 02
Modernisation roadmap
Rehost, re-platform, refactor or rebuild, decided module by module.
- 03
Strangler-pattern migration
New services replace old ones piece by piece behind a stable interface.
- 04
Database modernisation
Schema redesign and data migration with validation at every step.
- 05
API enablement
Modern APIs over legacy systems, so new apps and AI tools can use the data now.
- 06
Cloud re-platforming
Containers, managed services and CI/CD in place of hand-built servers.
03Outcomes
What changes once it’s live
- 01
A migration based on evidence
An inventory of dependencies, fragile boundaries and the business workflows that must keep running.
- 02
Controlled replacement
Incremental modernization with a defined cutover and rollback route instead of an unexplained big-bang rewrite.
- 03
A maintainable target
Documented interfaces, tests and deployment practices your team can evolve after migration.
04Approach
How we deliver it
- 01
Understand the running system
Review the code, data, infrastructure and undocumented behaviour with current maintainers.
- 02
Choose what to retain
Compare repair, wrapping and replacement, keeping stable parts when they still serve the business.
- 03
Migrate one boundary at a time
Add compatibility checks and data reconciliation around each move before switching traffic or ownership.
- 04
Retire deliberately
Verify migrated workflows, rehearse rollback and remove old components only after their responsibilities have moved.
05Stack
Tools we use most
- .NET
- Java
- Docker
- Kubernetes
- PostgreSQL
- Terraform
- Rust
- Spring
- Laravel
- Express.js
- gRPC
- Kafka
06Case studies
Featured success stories
Do we have to rewrite everything?
Rarely. Most systems are better served by re-platforming the stable parts and rebuilding the modules that slow you down.
Will there be downtime?
We plan migrations so users keep working: parallel runs, feature flags and cut-overs scheduled with your teams.
How do you handle undocumented code?
We map it with automated analysis and interviews, then write the documentation as part of the work.
How is the engagement priced?
We agree a fixed scope and price after reviewing the work, system dependencies and acceptance criteria. The pricing guide explains approved ranges for the engagement types it covers. A written proposal confirms what is included before a build starts.
How should the first delivery decision be made?
Review the code, data, infrastructure and undocumented behaviour with current maintainers. Compare repair, wrapping and replacement, keeping stable parts when they still serve the business.
What should the acceptance criteria cover?
An inventory of dependencies, fragile boundaries and the business workflows that must keep running. Incremental modernization with a defined cutover and rollback route instead of an unexplained big-bang rewrite. Documented interfaces, tests and deployment practices your team can evolve after migration.






