SAP to open-stack ERP migration
Manufacturer, 500+ employees. Phased migration off SAP ERP onto an open stack with custom modules — run in stages while the plant kept working.
- 0 downtime
- 8 mo migration
- −40% on licences
Legacy modernisation without stopping the business
A system that has been earning money for eight years is an asset, not an embarrassment. The skill is knowing which parts to keep, which to strangle and which to leave exactly as they are.
What we can show you
Legacy
Modernise or rewrite — the decision that costs the most
One question decides it: does the data model still match how the business works? Everything else is implementation detail.
What legacy modernisation actually is
Most legacy systems are not bad code. They are code whose context was lost: the people left, the documentation was never written, and the business rules survive only as behaviour. That is exactly why a rewrite from scratch loses more than it gains — it throws away the only written record of how the company works.
Modernisation means making change safe again: characterisation tests around the parts nobody understands, a supported platform version, dependencies that still receive security fixes, and a deployment anyone on the team can run. The system keeps earning throughout.
When to modernise and when to rewrite
Modernise when the data model still fits the business — then the rules inside are worth more than the code around them. Rewrite when the domain has changed beyond what the schema can express, or when the system solves a problem you no longer have. We cost both options before recommending one, because the wrong choice here is expensive in both directions.
Signals a system needs modernisation now
- the platform version no longer receives security fixes;
- there is one file nobody is willing to change;
- deployment is a person with an FTP client and a checklist;
- dependencies are years behind and updating them breaks something;
- the only documentation is the code, and its author has left.
Price
Audit $1,790, work from $7,990
Timeline
Audit in 5 days
Payment
50/50 by milestone
Comparison
Modernise in place or rewrite from scratch
Both options costed honestly, including the case where the rewrite wins and the engagement gets smaller for us.
Criterion
RewriteModernise in place
ModerniseRewrite from scratch
Business rules
Rediscovered by archaeology, some lost
Kept, then locked in by tests
Time to first benefit
Months, sometimes quarters
Weeks
Risk to daily operations
Concentrated in one cutover day
Spread thin: rollback at every step
Cost
Full project, paid before any benefit
A fraction, spread across releases
Team knowledge
New team learns the domain from scratch
Your people stay useful throughout
When it wins
Data model no longer matches the business
The system still fits the business
Process
How we change a system that cannot stop
Four mechanisms, in this order. Skipping the first one is how modernisation turns into an outage.
1. Characterisation tests first
We capture what the system does today — including its bugs — so a refactor can be proven not to change behaviour. Without this step, every later change is a guess with your revenue.
Refactoring never changes behaviour. If we find a bug on the way, we report it and price the fix separately rather than quietly «improving» something operations depend on.
2. Strangler, not big bang
New code beside old, traffic moved module by module, rollback available at every step. The business never stops, and no single day carries the whole risk.
Each module ships with its own acceptance criteria, so «done» is a check rather than an opinion.
3. Data migration with a dry run
Every migration is rehearsed on a copy first: row counts, referential integrity, a data-quality report and a documented cutover plan with a rollback window.
Our database migration services cover engine to engine and on-premise to managed — the part where teams lose data quietly, so it gets its own rehearsal and its own sign-off.
4. Delivery you can repeat
CI/CD, infrastructure as code, monitoring and a runbook a new engineer can follow. A modernised system that only one person can deploy is still legacy.
Long-term support is available afterwards from $790 a month, once the audit has told us what we are agreeing to support.
Why us
Why companies hand us a system that still earns
Four things we can prove, rather than four adjectives.
17 years of other people's code
230+ projects, and a large share of them started as somebody else's codebase. Reading unfamiliar systems is the skill this service is actually made of.
Rollback at every step
No cutover day that decides everything. Traffic moves module by module and every step has a way back — that is what lets the business keep trading during the work.
Both options costed
We quote modernisation and rewrite side by side before recommending one. The option that bills more hours is not automatically the one we push.
Your repository, your cloud
Code, infrastructure as code and documentation live in your accounts. After the work you own a system another team can run.
Industries
Legacy modernisationby industry
Old systems cluster where processes are old: warehouses, manufacturing lines, property back offices and finance departments.
- IT companies and digital agencies
- Insurers and brokers
- Lenders and microfinance
- E-commerce
- Wholesale and distribution
- Manufacturing
- Freight and forwarding
- Clinics and medical centres
- Dental
- Car dealers and service centres
- EdTech
- Legal and consulting firms
- Equipment rental
- Real estate agencies
- Property developers
- Travel and events
- Beauty and wellness
- Construction and renovation
FAQ
Legacy modernisation questions
Seven answers that usually replace a discovery call.
Modernise or rewrite?
Repair unless the data model no longer matches the business or the domain has changed beyond what the schema can express. We cost both options and show the numbers before recommending one.
Can you work without downtime?
Usually: parallel environments, traffic moved module by module and rollback at each step. Unavoidable windows are agreed in advance and kept short.
What if there are no tests at all?
Then that is step one. Characterisation tests capture current behaviour, bugs included, so a refactor can be proven not to change it.
Do you migrate databases as well?
Yes, with a dry run on a copy, a data-quality report and a documented cutover plan with a rollback window.
Is monolith to microservices always a good idea?
No. Most systems need three well-drawn boundaries, not thirty services. We will tell you when the monolith should stay and be cleaned up instead.
Will you work with our existing developers?
Often the fastest setup: they hold the domain knowledge, we bring the modernisation discipline and the review process.
What is in the audit?
Dependencies, security exposure, test coverage, deployment path and the flows that carry money, with a prioritised plan. $1,790, credited against the work that follows.
2–4×
faster on the code-writing share
in 3 weeks
from idea to MVP
230+
projects delivered
17 years
of engineering experience
Work
Work we can show you
SMARTWILL
Digital inheritance service (Web3)
AIRDEVELOPPA
Indoor air quality finder driven by sensor data
CAR5
Car-sharing app
APP.DENTAL
Cloud CRM for dental clinics
NEXORA
Warehouse and logistics management platform
As-built docs
Digital as-built documentation
EX211
Telegram Mini App for currency exchange
SMARTWILL
Digital inheritance service (Web3)
Have a system nobody wants to touch?
Send the stack, the version and what breaks most often. You get an audit plan and a fixed quote for the first safe step — and an honest answer if a rewrite is cheaper.