- companies with old systems
- support teams
- developers inheriting undocumented code
Gradual modernization
Legacy systems and documentation
This hub helps teams turn old systems into understandable systems. The focus is documentation that supports maintenance, risk mapping, supplier handover, modernization planning and small improvements that reduce fear around change.
- Which business flows must be documented before touching code.
- How to reduce dependency on one developer, supplier or memory source.
- When modernization is safer than rewriting from scratch.
- How to turn scattered knowledge into a technical continuity plan.
Reading path
Start with the strongest context already available in the portal.
Some deeper references still point to Portuguese source articles while the full English migration continues. The English hub itself gives the decision map and the language relationship stays explicit.
First steps to document a legacy system
Portuguese guide to start documentation without freezing operation.
Open referenceHow not to lose supplier context
Portuguese article about handover and technical ownership.
Open referenceModernizing Java without rewriting everything
Portuguese article about incremental modernization.
Open referenceHow to use this hub
Treat this page as a decision map. The purpose is to help you name the problem before choosing a framework, vendor, refactor or automation. When the topic is clearer, the linked material becomes easier to interpret and compare.
The English migration is intentionally additive: the Portuguese portal remains stable, and each English page receives its own route, canonical URL and language alternates.
Terms to align before going deeper
FAQ
Common questions before acting on legacy systems and documentation.
Where should legacy documentation start?
Start with critical business flows, data, integrations, jobs, environment variables, deployment routine and known operational risks.
When is rewriting a legacy system dangerous?
Rewriting is dangerous when business rules are implicit, data behavior is unclear and the old system still carries knowledge no one has documented.
How do you reduce key-person dependency?
Create checklists, access inventory, technical notes, decision records and regular knowledge transfer around the flows that affect operation.
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