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Top 42 Elixir Interview Questions & Answers (2026)

42 Questions 20 Beginner 12 Intermediate 10 Advanced

About Elixir

Top 50 Elixir interview questions covering functional programming, OTP, GenServer, Phoenix, concurrency, fault tolerance, and the BEAM VM. Companies hiring for Elixir roles test this knowledge at every stage — from first-round screens that check the basics to final-round conversations about real-world trade-offs.

What to Expect in a Elixir Interview

Expect a mix of conceptual and practical Elixir questions: clear definitions and core-concept checks for junior roles, hands-on scenario questions for mid-level roles, and architecture or trade-off discussions for senior roles. Interviewers usually move from foundational topics toward the kind of problems you'd actually face on the job.

How to Use This Guide

Work through the Elixir questions in order — Beginner, then Intermediate, then Advanced — so each concept builds on the last. Every question has its own page; bookmark the ones that trip you up and revisit them the day before your interview.

Curated by Tech Baithak Editorial Team · Last updated: May 2026

Beginner 20 questions

Core concepts every Elixir developer must know.

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?

Intermediate 12 questions

Practical knowledge for developers with hands-on experience.

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?

Advanced 10 questions

Deep expertise questions for senior and lead roles.

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?

Back to All Topics 42 questions total