Top 42 Elixir Interview Questions & Answers (2026)

01 What is Elixir? 02 What is the BEAM virtual machine? 03 What is pattern matching in Elixir? 04 What are Elixir processes? 05 What is OTP in Elixir? 06 What is GenServer in Elixir? 07 What is a Supervisor in Elixir? 08 What are Elixir modules and functions? 09 What are Elixir data types? 10 What is the pipe operator in Elixir? 11 What is Phoenix Framework? 12 What is Ecto in Elixir? 13 What is Phoenix LiveView? 14 What is immutability in Elixir? 15 What are Elixir structs? 16 What is the "let it crash" philosophy in Elixir? 17 What is ExUnit in Elixir? 18 What is Mix in Elixir? 19 What is the difference between send/receive and GenServer in Elixir? 20 What are Elixir protocols?

01 How do Elixir supervisors implement fault tolerance? 02 What is Phoenix Channels and how do WebSockets work in Elixir? 03 What is Elixir's concurrency model compared to threads? 04 What are Elixir behaviours? 05 What is Elixir's error handling approach? 06 What is a GenStateMachine in Elixir? 07 How does hot code upgrading work in Elixir/Erlang? 08 What is ETS (Erlang Term Storage) in Elixir? 09 What is the Registry module in Elixir? 10 What is Task in Elixir? 11 What is Elixir's Enum and Stream modules? 12 How does Elixir handle distributed computing?

01 What is the Elixir macro system and how does metaprogramming work? 02 What is Elixir's GenServer deep internals and message queue management? 03 What is Broadway in Elixir and how does it handle data pipelines? 04 What is GenStage in Elixir? 05 How does Elixir handle cluster formation and distributed state? 06 What is Nx and Machine Learning in Elixir? 07 What are Elixir's process monitoring, tracing, and debugging tools? 08 What is the Reactor library and event-driven architectures in Elixir? 09 How does Elixir's Ecto handle complex queries and associations? 10 What is the Commanded library and event sourcing in Elixir?