legacy system
Old but necessary
A legacy system is older technology—software, hardware, or infrastructure—still in use despite being outdated.
Organizations keep legacy systems running because replacement is expensive, risky, or because critical processes depend on them: Half our budget goes to maintaining legacy systems no one fully understands anymore.
The term implies something burdensome but too embedded to easily remove.
Old and outdated
- outdatedNo longer in use
- archaicBelonging to earlier times
- deprecatedFormally advised against using
- end-of-lifeNearing death phase
unsupported · sunset · phaseout · decommission · retirement · technical debt · inefficient · clunky
Large centralized computer system
- COBOLElderly business-oriented programming language
- databaseOrganized digital information collection
- middlewareInter-application bridging software
- architectureBuilding design discipline
integration · migration · compatibility · upgrade · patch · maintenance · support · interface
Large centralized computer system
- serverOne who attends tables
- hardwareMetal goods and fittings
- on-premisesInstalled locally, not cloud
- data centerFacility housing networked computers
network · storage · backup · disaster recovery · enterprise · mission-critical · production · uptime
Movement to new territory
- refactoringCode improvement, same behavior
- replatformingMoving systems between platforms
- containerizationStandardized cargo packaging system
- microservicesDecomposed application architecture
digital transformation · replacement · upgrade path · interoperability · wrapper · middleware · incremental · cutover
antiquated
Old and outdated
- outdatedNo longer in use
- archaicBelonging to earlier times
- deprecatedFormally advised against using
end-of-life · unsupported · sunset · phaseout · decommission · retirement · technical debt · inefficient · clunky · bottleneck
mainframe
Large centralized computer system
- COBOLElderly business-oriented programming language
- databaseOrganized digital information collection
- middlewareInter-application bridging software
architecture · integration · migration · compatibility · upgrade · patch · maintenance · support · interface · batch processing
mainframe
Large centralized computer system
- serverOne who attends tables
- hardwareMetal goods and fittings
- on-premisesInstalled locally, not cloud
data center · network · storage · backup · disaster recovery · enterprise · mission-critical · production · uptime · reliability
migration
Movement to new territory
- refactoringCode improvement, same behavior
- replatformingMoving systems between platforms
- containerizationStandardized cargo packaging system
microservices · digital transformation · replacement · upgrade path · interoperability · wrapper · middleware · incremental · cutover · roadmap
- IT systemssoftware, server, hardware, servers, databases
- tech adoptionadoption rate, technology adoption, early adopter, early adopters, late adopter
- Enterprise ITserver, servers, data center, cloud computing, virtualization
- compatibilitycompatible, incompatible, match, mismatch, fit
- phase-outssunset, wind-down, discontinuation, sunset clause, termination
- data systemsdatabase, data warehouse, data lake, data model, schema
legacy, system, legacies, systems, systematic, systematize, systematization, systemic, systemically