P0

🔴 P0 — the holy grail of distributed message processing; critical for payments

🔴 P0 — the foundational impossibility result and its more nuanced successor

🔴 P0 — the craft of designing APIs; shows engineering judgement, not just pattern knowledge

🔴 P0 — appears in nearly every system design interview

🔴 P0 — DDIA Ch4 core content; underpins the gRPC proxy pattern and API versioning

🔴 P0 — foundation for reasoning about inter-service communication, latency, and failure modes

🔴 P0 — the default replication strategy for most production databases

🔴 P0 — the first data decision in every design; determines query flexibility, scaling, and consistency

🔴 P0 — the spectrum from linearisability to eventual consistency

🔴 P0 — appears in nearly every system design; the single entry point pattern