Curated Picks

A Reddit discussion on Elixir's functional programming (FP) purity attracted extensive debate among practitioners. Proponents of strict FP definitions, citing languages like Haskell, noted Elixir's allowance of side effects via message passing and I/O breaks referential transparency. Others defended its pragmatic, immutable-by-default approach as sufficiently functional for building concurrent systems. Concrete outcomes included developers distinguishing between learning FP fundamentals (favoring Haskell) and applying FP patterns to web development (choosing Elixir). The discourse highlighted Elixir's design trade-offs: leveraging the BEAM's actor model for concurrency while accepting constraints like its limited built-in data types.

In May 2020, a Hacker News thread titled "Who regrets choosing Elixir?" ran for several days and accumulated more than 300 comments. Many participants coming from Ruby and Rails backgrounds reported positive experiences, particularly around concurrency-heavy workloads such as WebSockets, and pointed to system stability over time. Others, often describing teams that later moved away, focused on recurring friction points: difficulty hiring engineers comfortable with BEAM and OTP concepts, a comparatively small ecosystem that pushed teams toward maintaining internal libraries, and operational complexity when Erlang-style supervision hierarchies were combined with container-based deployment models.

The thread included accounts of companies rewriting Elixir services in more widely adopted languages after key developers left, citing increased on-call load and reduced maintainability. At the same time, other contributors described organizations that adopted Elixir selectively after internal evaluations and standardized on it for new infrastructure where its concurrency model was seen as a good fit.

A 2019 Hacker News discussion on Elixir featured developers reporting order-of-magnitude performance gains, with one user claiming a 10x speed increase after rewriting a Django app in Phoenix. Participants debated the significance of TechEmpower benchmarks, while creator José Valim detailed specific BEAM VM optimizations like iolists and per-process GC that benefit web workloads. The thread also highlighted improved deployment tooling since Elixir 1.9 and ongoing community debate around the language's lack of a static type system for catching errors earlier. Multiple commenters noted adoption hurdles, including a smaller ecosystem and fewer available developers compared to mainstream languages.

In a 2019 interview, Elixir creator José Valim described the language's origin as a response to the multi-core programming challenge. He stated that adopting functional programming's immutable data and the Erlang VM's distributed-process model made whole classes of concurrency bugs "disappear". Valim emphasized that easing the learning curve through integrated tooling was a primary design goal to encourage adoption. The interview presents Elixir as a synthesis of ideas from languages like Clojure and Haskell, built upon the Erlang runtime.