Q: You are tasked with migrating a massive legacy application from on-premises to the cloud. You cannot afford to refactor the code (Cloud Native). Describe the "Lift and Shift" (Rehosting) approach and its major operational downsides.
Lift and Shift (Rehosting) means cloning the physical/virtual machines byte-for-byte directly into identical cloud VMs (like AWS EC2) wit...
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🎙️ Candidate Opening & Architectural Context
""In our engineering organization, DevOps culture meant aligning developer speed with site reliability. The interviewer is testing: Cloud migration patterns, operational trade-offs, technical debt.. I structure my answer around systematic triage first, root cause analysis second, and permanent remediation third.""
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🛠️ Production Runbook & Step-by-Step Resolution
1️⃣
Initial Diagnostics & Root Cause Analysis
Lift and Shift (Rehosting) means cloning the physical/virtual machines byte-for-byte directly into identical cloud VMs (like AWS EC2) with zero architectural changes to the application itself.
- Cost: Legacy apps typically expect vertical scaling (massive servers) running 24/7. You miss out on the cost savings of auto-scaling, pausing idle resources, or using cheap serverless compute.
- Resilience: The app likely expects persistent, permanent local disks and fixed IP addresses, making it fragile if the underlying EC2 instance is randomly terminated by the cloud provider. It physically cannot utilize cloud-native elasticity.
2️⃣
Remediation & Permanent Safeguards
Major Operational Downsides: Because the app is not "Cloud Native", you inherit all on-premise technical debt at cloud prices.
💡 The Senior SRE Gold Nugget (Key Architectural Takeaway)
"Pro-Tip: Cost: Legacy apps typically expect vertical scaling (massive servers) running 24/7. You miss out on the cost savings of auto-scali."
⚡ 60-Second Elevator Pitch Talking Points
- Cost: Legacy apps typically expect vertical scaling (massive servers) running 24/7. You miss out ...
- Resilience: The app likely expects persistent, permanent local disks and fixed IP addresses, maki...
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