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2988 questions of the kind that actually get asked — in interviews, in architecture review boards, and by the person who has to run the thing at 3 AM. Every answer states the trade-off rather than the slogan, and says when the obvious choice is the wrong one.

All areas2988 Architecture Fundamentals91 Distributed Systems111 Data Architecture100 Cloud Architecture97 Networking96 API & Integration Architecture97 Reliability & Resilience99 Observability92 Performance & Capacity Engineering100 Security Architecture105 Cost Architecture & FinOps102 Business Architecture103 Architecture Communication102 Enterprise Architecture100 Legacy Modernization102 AI-Era Architecture106 Software Architecture & Engineering93 Architecture Patterns94 Architecture Decision-Making101 The Architect's Meta-Skills102 Delivery & Release Engineering103 Platform Engineering & Developer Experience102 Testing & Quality Architecture102 Data Platform Architecture98 Streaming & Real-Time Data103 Data Governance & Semantics91 Frontend & Experience Architecture101 Edge, Mobile & IoT98 Regulatory & Data Protection Architecture99 Assurance, Audit & Model Risk98
Difficulty Any beginner intermediate advanced

6 questions in Cost vs Reliability.

  1. Cost vs Reliability advanced

    A cost-sensitive platform must choose between a highly available architecture and a cheaper one with a wider failure domain. How should the decision be made?

    2 min answer physics-wallahcostreliabilityslo
  2. Cost vs Reliability advanced

    A team is asked to reduce infrastructure cost by 30%. How do you make the reliability trade-off explicit rather than accidental, and what should be cut first?

    2 min answer costreliabilityslotradeoff
  3. Cost vs Reliability advanced

    One architecture has excellent performance and mediocre reliability; another is reliable at substantially higher cost. How should the trade-off be evaluated?

    2 min answer cost-vs-reliabilitysloerror-budgetbusiness-impact
  4. Cost vs Reliability advanced

    Roblox's January 2022 postmortem on the October 2021 incident states that the outage lasted 73 hours, that it ran its back-end services on a single Consul cluster, and that the single cluster supporting multiple workloads exacerbated the impact. Running one shared coordination cluster rather than one per workload is a real and defensible saving. What was that saving worth, and what decision rule follows?

    3 min answer robloxconsulblast-radiusconsolidation
  5. Cost vs Reliability advanced

    To cut 45% from database spend a team moved the primary from a synchronous two-zone pair to a single zone, with snapshots every 30 minutes and log shipping every 5. The zone never fails. It gets slow - storage latency goes from 1 ms to 80 ms and stays there for two hours. What happens, minute by minute?

    3 min answer grey failureavailability zonesrpodetection
  6. Cost vs Reliability advanced

    What would it cost to move a service from 99.9% to 99.99% availability, and how would you decide whether it is worth it?

    2 min answer availabilitycostslotradeoffs