The original team is gone or overstretched
Bugs go unfixed, and every new feature takes longer and breaks more.
Takeover System takeover
Your legacy system?
We'll JoinX that too.
The original vendor is gone, there's no documentation, and changing one line breaks three others. We've taken over more than a hundred systems like that. We audit and stabilize first, then decide what to renew. There's no need to rewrite everything at once, and no need to shut the system down.
- systems taken over
- 100+
- source-code audit and environment setup
- 1–2 weeks
- system fully understood, basic bugs fixed
- 1 month
- maximum support hours (from 5×8)
- 7×12
- 01 Audit
- 02 Stabilize
- 03 Renew
- 04 Keep building
Signals Time to bring in a new team
The problem isn't that the system is old. It's that nobody dares to touch it.
No documentation; change one line, break three
The core logic lives in a few people's heads, so every change feels like defusing a bomb.
Every release is a gamble
Without tests, version control or a way to roll back, each deployment is nerve-racking.
Your data is locked in the old system
New channels and systems can't connect, so data is exported and imported by hand.
Performance can't keep up with growth
Pages slow down and peaks bring the system down; the old architecture can't scale with your users.
Maintenance keeps getting more expensive
Hours keep rising while delivery keeps slowing, and technical debt keeps piling up.
How we take over Four steps
Stabilize first, renew next, then keep growing.
Every step has clear deliverables you can sign off, and you can stop after any of them.
Audit: code, architecture and security risks
About 1–2 weeksOnce authorized, we rebuild knowledge of the system from its source code, database, runtime environment, logs and real user flows, so we can assess it even without documentation. We also set up development and test environments, so every later change can be verified first.
- DeliverableTechnical debt map
- DeliverableSecurity risk list
- DeliverableTest sandbox
Stabilize: fix the high-risk issues first
First month of the takeoverWe rank issues by business impact, fix the known critical bugs and security vulnerabilities first, and add automated tests, version control and a release process you can roll back. The system has to be stable before we talk about renewal.
- DeliverableVulnerability fixes
- DeliverableCI/CD and monitoring
- DeliverableRollback-ready releases
Renew: refactor or rewrite as the business needs
In phasesWe decide which modules to keep, refactor, replace or retire. High-risk modules are isolated first, then switched over gradually with old and new running side by side. An old module is retired only once the new version has proven stable.
- DeliverableTarget architecture
- DeliverableMigration and rollback plan
- DeliverablePhased roadmap
Keep building: the next version, still the same team
Long-term partnershipWe settle into a regular maintenance rhythm of bug fixes, version updates and performance tuning, while taking on new business requirements. With the technical documentation and architecture diagrams filled in, the system no longer lives only in one person's head.
- DeliverableTechnical documentation
- DeliverablePerformance tuning
- DeliverableNew feature development
Modernization No big-bang rewrite
Three ways to renew. Choose by risk, not by preference.
Refactor in place
- Best for
- The features still have value; only the structure needs work
- Watch out for
- Put tests in place before touching the structure
Add an API layer
- Best for
- You need to connect new systems or channels, but the data is locked in an old database
- Watch out for
- First make clear who owns each set of data
Rebuild in phases
- Best for
- Technical and operational risks are both high, and the current architecture can't go on
- Watch out for
- Side-by-side operation and switch-over criteria must be designed
Your business keeps running while the system changes.
We migrate data in batches, write to the old and new systems in parallel, validate the new version with shadow traffic, and keep a rollback path for every release. The exact approach depends on your data-consistency requirements, and we agree on the rollback criteria together before switching over.
Old system
New system
Traffic
Run in parallel → shift traffic step by step → retire old modules once stableSupport Coverage after the takeover
From 5×8 to 7×12: as much care as your system needs.
5×8Business-hours support
- Bug fixes and version updates
- Server and system administration
- Regular security patching
7×12Extended-hours support
Daily, 9:00 am – 9:00 pm (GMT+8)
- Someone on hand on weekends and holidays
- Monitoring alerts and rapid response
- Performance tuning during peak periods
- New feature development as the business requires
- Full source-code audit
- Automated monitoring and deployment
- Security patching
- Performance bottleneck fixes
- Technical documentation
- Cloud migration
- ISO 27001 processes
Started with a takeover Clients
At first, all they wanted was a stable system.
Capital Investment Trust
Finance · Takeover and maintenance
An IT development partner that meets FSC standards.
Fundhot
Investment community · Takeover, optimization, security
From website optimization and product development to security, we've kept working together ever since.
Read the full case →TAITRA
Public sector · System takeover
Since the takeover, we have kept maintaining and extending the system.
FAQ Before you get a quote
Let's be clear before any quote.
How long does it take to take over a system with no documentation at all?
We usually complete the source-code audit and environment setup within 1–2 weeks, and fully understand the system and fix the basic bugs within a month. After that, we decide whether to renew or rewrite based on business needs, and keep developing new features.
Does everything have to be rewritten?
Not necessarily. Most companies are better off isolating the high-risk modules first, adding tests and deployment capability, and then replacing parts step by step. We'll tell you up front which parts are worth keeping.
Can you assess the system without any source-code documentation?
Yes. We rebuild knowledge of the system from its source code, database, runtime environment, logs and real user flows, and add architecture diagrams and documentation during the audit.
Will the system go down while it's being renewed?
Downtime can be avoided with batched data migration, dual writes to the old and new systems, shadow traffic and releases that can be rolled back. The exact approach depends on your data-consistency requirements, and we agree on the rollback criteria together before switching over.
How is the maintenance fee calculated after the takeover?
It's planned around the system's complexity, how outdated its technology is, and the support hours (5×8 to 7×12) and response times you need. It can be ongoing maintenance or a one-off renewal project.
Get started Book a takeover assessment
Tell us where your system is stuck.
- 1A sales manager replies within 1 business day
- 2We can sign an NDA before you share any source code
- 3We quote only after the assessment, with acceptance criteria spelled out for every item