Legacy software migration
Modernize your software without stopping the business.
I analyze what the system contains, what risk it carries, and the safest transition — without starting with a blind rewrite.
In an initial 30-minute conversation we review context, criticality, the urgency trigger, and whether an assessment is a fit. You do not need to share code or confidential information at this stage.
What legacy means in practice
Legacy is not just old code. It is software that sustains operations, revenue, or compliance — but has become hard to change with confidence.
- Slow or risky changes
- Knowledge concentrated in few people
- Unsupported stack or unreliable tests
- Incomplete or outdated documentation
- Fragile integrations nobody wants to touch
When to modernize
- Product or operations cannot evolve at business pace
- Investment, sale, audit, or vendor transition is coming
- Keeping the system costs more than a planned transition
- You need new integrations or capabilities with control
When not to rewrite
I do not start by rewriting. First I understand what logic must be preserved, what can be retired, and what can move in waves.
- If stopping operations is too risky
- If domain knowledge lives only in the code
- If behavior evidence is missing (tests, logs, contracts)
- If the real issue is ownership, not language
Possible strategies
Retain / Retire
What to keep and what to shut down with evidence.
Rehost / Replatform
Move with bounded infrastructure or platform changes.
Refactor / Rebuild
Intervene on critical modules or rebuild specific domains.
Progressive strangler
Coexistence, feature flags, dual run, and wave-based cutover.
Role of AI
AI to accelerate. Expert judgment to decide and validate.
- Analysis and documentation
- Dependency detection
- Characterization test generation
- Functional comparison and rule extraction
- Never a substitute for architecture, security, or accountability
Assessment deliverables
- Risk and dependency map
- Retain / retire / rehost / replatform / refactor / rebuild options
- Suggested sequence and cutover risks
- Data, testing, and rollback plan
- Range estimates when evidence is sufficient
What happens in the first meeting
In an initial 30-minute conversation we review context, criticality, the urgency trigger, and whether an assessment is a fit. You do not need to share code or confidential information at this stage.
Useful to prepare
- System or product
- Known technology
- Approximate age
- Business criticality
- Main problem
- Current team
- Urgency trigger
- Approximate deadline
What does not happen
- — No free full audit
- — No repository access required
- — No credentials requested
- — No secrets shared
- — No budget promised without diagnosis
FAQ
- Is migration the same as a rewrite?
- No. Migration can include coexistence, strangler, replatform, or selective refactor. Full rewrite is an option — not the starting point.
- Can you guarantee zero downtime?
- No. I design transitions that minimize interruption and maximize control (rollback, observability, waves). Continuity is planned; it is not magic.
- Do we start with code access?
- The first meeting does not require repository access. If there is fit, the next step is usually a Legacy Risk Scan or a paid audit.