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interview_prep/system_design/readme.md

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+## Gather System Requirements
+- FR
+- NFR (Scale)
+- NFR (Latency and Availability)
+
+## Planning
+- Data Model -> Core functionality
+- User Flow
+
+## Estimation
+- 1 Estimation Cheat Sheet.
+Units Cheat Sheet
+These values are defined by the International System of Units.
+* 1kB = 1000 bytes
+* 1MB = 1000kB
+* 1GB=1000MB
+* 1TB =1000GB
+* 1PB=1000TB
+Storage Scale Cheat Sheet
+* Acharacter
+=>1 byte
+* Typical metadata for a "thing," excluding images (name, description, other attributes, etc.)
+=>~1-10KB
+* A high-quality 1920x1080p image
+=> ~2M8 (realistically can be lossy-compressed by ~10-20x)
+* 20 minutes of HD video
+=>~1GB
+Storage Capacity Cheat Sheet
+How much storage can a single industry-grade machine have?
+« ~1078 disk space
+« ~256GB-1TB of RAM (178 for really large/optimized machines)
+Latency Cheat Sheet
+How long does it take for a regular HTTP request to make a round trip, not bound by bandwidth?
+« Intra-continental
+=>~50-150ms
+« Cross-continental
+=>~200-500ms
+Bandwidth Cheat Sheet
+« Mobile phone (4G)
+=> ~13MB/s
+« Public internet (home WiFi)
+=> ~50-100MB/s
+« Within a data center
+=> ~5GB/s