This skill should be used when choosing "data structures", "Map vs ETS vs gb_trees performance", evaluating "hash functions", needing "HyperLogLog or bloom/cuckoo filters", or comparing OTP built-ins against specialized alternatives for Elixir
This skill should be used when code is hard to understand, a module has "too many parameters or deep nesting", "functions exceed 40 lines", "abstractions feel leaky", or evaluating "deep-module vs shallow-module" design per Ousterhout principles
This skill should be used when building "multi-node Elixir systems", choosing between "Raft and CRDTs", configuring "libcluster or Partisan", debugging "split-brain or netsplit scenarios", evaluating "CP vs AP tradeoffs", investigating "data loss" in distributed pipelines, working with "Kafka", "RabbitMQ", "Broadway", or "PubSub" message delivery guarantees, or designing "event streaming" architectures
This skill should be used when structuring Elixir code, deciding whether to use "GenServer or plain functions", "designing supervision trees", "handling overload or unbounded message queues", "organizing Phoenix contexts", or needing idiomatic OTP patterns
This skill should be used when about to run "git commit", "git push", or claim implementation is complete in an Elixir project — requires running mix precommit and confirming output before any commit or completion claim
This skill should be used when code is reported slow, before suggesting any optimization, when choosing between "cprof/eprof/fprof/tprof", or when creating "Benchee benchmarks" to compare approaches
This skill should be used when working with "Phoenix LiveView", "Plug pipelines", "controllers", "JSON APIs", "channels", "streams", "forms", "phx-hook", "authentication", or debugging "Phoenix/LiveView gotchas"
This skill should be used when preparing code for production, running "mix precommit", "mix compile --warnings-as-errors", "mix credo --strict", "mix format", "mix test", adding typespecs, evaluating security posture, checking migration safety, or reviewing code before committing