Comparisons

REST vs gRPC vs GraphQL: decision table by traffic type; trade-off analysis across caching, schema, streaming, browser support, evolution; mixing protocols; chatty API anti-pattern

All 8 architecture styles rated side by side; decision guide; monolith vs understanding-distributed-systems; partitioning type

Build vs buy vs open-source decision framework; subdomain type as the primary analytical tool (core → build, generic → buy/adopt, supporting → build simple); hidden costs of buying; platform team as internal build-once option; sourcing reversals as subdomain types evolve

When to use linearizability vs causal vs eventual consistency; timeliness vs integrity distinction; decision guide by scenario (locks, balances, feeds, shopping carts, multi-region); read routing as the practical knob; CAP trap warning

Nines table with money attached; conversion via downtime cost; investment cost per nine; where each nine is earned; antipatterns (tyranny of the nines, MTBF without MTTR, redundancy without isolation); architectural choices that make availability cheap or expensive

How far to decompose: modular monolith → service-based → microservices; five decision factors (domain understanding, team structure, DevOps maturity, transaction requirements, scalability); recommended migration path; granularity disintegrators vs integrators; Ferrari anti-pattern

Decision tree: where's the seam, is correctness the dominant risk, granularity, duration, parallel-run cost; pattern composition (service extraction, embedded capability extraction, database split, platform migration); database decomposition patterns; rollback as a feature

Decision guide: when to use a central coordinator vs event-driven choreography; team-ownership heuristic; God Orchestrator anti-pattern; workflow state management options

Symptom → diagnosis → action playbook; three analytical lenses (Little's Law, utilisation curve, percentile arithmetic); capacity planning workflow; antipatterns (sizing for average, running at high utilisation, unbounded queues); when performance tuning doesn't apply

Which stability pattern when; selection decision tree (outgoing call, incoming request, internal pipeline, system edge, automation, resource pooling); pattern × antipattern matrix; composition order (timeout first, then bulkhead, then breaker, then retry, etc.); anti-patterns of pattern composition

When to use synchronous vs asynchronous communication; temporal coupling as the core distinction; availability chaining risk; async concerns (idempotency, ordering, correlation, observability); mixed model (sync north-south, async east-west); decision guide