Mold - a tiny, zero-dependency parsing library for external payloads

Mold parses JSON APIs, webhooks, HTTP params and other external input into clean Elixir terms - coerces types, renames keys, checks structure, and returns {:ok, result} or {:error, errors} with traces.

Cheatsheet | Documentation | Hex | GitHub

You're probably underusing middleware for HTTP response handling

A note on a pattern I keep running into in Elixir API clients: status-code checks and body parsing live in code after Tesla.request, instead of inside the middleware chain itself. It looks fine from the caller’s side, but it silently breaks observability. A 500 translated to {:error, _} looks like a successful request to Tesla, so :telemetry and anything else wired up to the request lifecycle stay quiet.

https://dev.to/arturplysiuk/youre-probably-underusing-middleware-for-http-response-handling-1djf

How do I write Elixir tests?

Personal guides for writing tests that are readable and maintainable. Stuff to use, stuff to avoid, and how to organize stuff.

Furthermore, I think that mocking must be destroyed.

https://hauleth.dev/post/writing-tests/

Concurrency, understanding the BEAM limits - Lorena Mireles Rivero [webinar]

https://www.erlang-solutions.com/webinars/concurrency-understanding-the-beam-limits/

The BEAM makes concurrency powerful, but resilient systems come from understanding capacity limits and designing around them.

Watch Lorena’s webinar where she breaks down how schedulers, mailboxes, and latency behave under load, and explains approaches like workload distribution, back pressure, and graceful degradation. All that with real-world examples.

FastDecimal 1.0 — a pure-Elixir alternative to decimal, ~11× faster

FastDecimal is a pure-Elixir decimal library aimed at workloads where the arithmetic itself is the bottleneck (ledgers, pricing, batch sums). Geomean ~11× faster than decimal across add/sub/mult/div/compare/parse on BEAMAsm — see the benchmark table for the full run.

Migration is one line for typical code: alias FastDecimal.Compat, as: Decimal. Full feature parity with decimal except Decimal.Context (intentional — precision is per-call).

Hex: https://hex.pm/packages/fastdecimal · Docs: https://hexdocs.pm/fastdecimal · GitHub · Migration guide

Updates to Permit: Igniter setup and better defaults

The Permit authorization suite has just got a batch of updates with Igniter-powered generators for Phoenix, Ecto and Absinthe. Read Dawid’s release notes article at the Curiosum blog.

Thinking Elixir 303: The Taming of the Slop

Episode 303 of Thinking Elixir. News includes the Erlang Ecosystem Foundation publishing its 2026 board election candidates with voting now open, a new GitHub organization called Elixir-Vibe launching with tools to detect and fix AI-generated Elixir “slop” — including ExSlop and the related semantic linter Credence, erlang_python 3.0.0 arriving with true parallelism by embedding CPython into the BEAM as a first-class citizen, ElixirConf EU 2026 videos beginning to drop including keynotes from José Valim and Chris McCord, and more!

https://www.youtube.com/watch?v=t-VuB97ZY2c

Reflecting on Event Sourcing ElixirConf

I talked about Event Sourcing in August and it just went up on youtube. It was a nice chance to reflect on what’s changed in the last 6 months and what I’m appreciating now. https://sylverstudios.dev/blog/2026/05/12/event-sourcing-elixir-conf

Lockstep — find race conditions in BEAM code and replay them on demand

Lockstep is a concurrency test runner for the BEAM. You write what looks like an ExUnit test; it runs many times under controlled scheduling, and when it finds a race it gives you the exact schedule to replay.

Real bugs surfaced building it: Phoenix.Tracker pre-fc5686f, NimblePool pre-e18f45f, Hammer’s Atomic.FixWindow.inc/4.

Features:

• 5 scheduling strategies + trace replay + counterexample shrinking
• Drop-in OTP wrappers (GenServer, Task, Registry, Supervisor, ETS, Atomics, …)
• AST rewriters for Elixir + Erlang — works on unmodified upstream source
• Multi-node Lockstep.Cluster with partition / heal
• Optional Anthropic Claude integration to explain failing traces

https://github.com/b-erdem/lockstep

TelegramEx – make Telegram bots with ease

Built telegram_ex to make Telegram bot development in Elixir less painful.

Macro-based API handles boilerplate for you.

Features:

• Text, photos, documents, stickers, video
• Inline & reply keyboards
• Stateful FSM with routers
• And more…

Would be appreciate your feedback!

https://github.com/lsdrfrx/telegram_ex

Hologram UI waiting list is open - what components should ship first?

Hologram UI waiting list is now open - the official component library for Hologram, the full-stack Elixir framework that compiles Elixir to run in the browser. The case for a maintained library in the LLM era: components need accessibility, responsive design, and consistency across the set - not just markup. https://hologram.page/ui

Designing a Broker-Agnostic API Layer in Elixir

Four Elixir behaviours — Broker, BrokerAdapter, AccountManager, MarketDataSource — keep broker-specific quirks out of the trading pipeline entirely; this post covers the dispatch mechanism, how partial implementations are handled, and two design decisions worth revisiting.

ElixirCasts 205: Deploy Phoenix to a VPS

Ever wanted to deploy your Elixir apps to a VPS?

In episode 205, we use Tidewave to build a Phoenix app and Potions to deploy it to a VPS we own.

https://elixircasts.io/deploy-phoenix-to-a-vps-in-minutes-205

Thinking Elixir 302: BEAM in Your Pocket

Episode 302 of Thinking Elixir. News includes Mob, an exciting new framework that brings BEAM-on-device mobile development to Elixir with OTP running natively inside iOS and Android apps, Folio a new library for generating print-quality PDFs and SVGs from Elixir data powered by Typst via Rustler NIF, both Oban v2.22 and Oban Pro v1.7.0 were released with a host of improvements including job querying, unique workflows, and a rate limiting overhaul, LiveVue v1.1 arrives with Node-less SSR via QuickBeam and persistent layouts, erlang_quic v1.3.0 brings a production-ready pure-Erlang QUIC and HTTP/3 stack to OTP 27, and more!

https://www.youtube.com/watch?v=iQCElquebAo

ExRatatui Update

Elm-style reducer runtime, new widgets (Chart, Canvas, Calendar, Sparkline, BarChart) and a Widget protocol, SSH and distribution-attach transports, telemetry, guides, and Livebook integration via kino_ex_ratatui. Would love to hear feedback and what you build with it.

Repo & Docs.

Error Tracker v0.9 has been released

We have just released a new version of ErrorTracker, the Elixir based built-in error tracker. This version adds a few improvements related to Telemetry events:

• Include the Occurrence in :error Telemetry events
• Propagate muted flag to :error Telemetry events
• Improve sensitive header redaction
• Switch the codebase from Credo to Styler
• Fix compilation warnings under the upcoming Elixir 1.20

Take a look at the GitHub repository and the Hex.pm package for the detailed release notes and documentation.

Self-hostable Ngrok clone in Elixir

A (simple) clone of Ngrok using Elixir. Inspiration after reading ‘Network Programming in Elixir’ and general curiosity gave me the idea. Binary pattern matching, network protocols, a little Rust client made this a joy to build.

https://github.com/m1dnight/ferri

Thinking Elixir 301: Testing, Debugging, and Departures

Episode 301 of Thinking Elixir. News includes Phoenix LiveDebugger hitting v1.0 with an interactive tour to go along with it, LiveStash v0.2.0 shipping with API improvements and a tease of Redis & Mnesia adapters on the horizon, German Velasco making his TestingLiveView.com course completely free for the Elixir community, Volt reaching v0.8.0 as an Elixir-native frontend build tool that eliminates the need for Node.js, and Francesco Cesarini announcing his departure from Erlang Solutions while pledging to remain active in the Erlang Ecosystem Foundation, and more!

https://www.youtube.com/watch?v=rO-y4ELOOZs

The Broker Evaluation Gauntlet: Four Futures APIs Compared

A production comparison of four broker APIs — covering OAuth flows, streaming protocols (SSE vs WebSocket), symbol conventions, and order execution reliability — from an Elixir system that integrated them all and removed one.
https://seriousalchemy.com/broker-evaluation-gauntlet

Thinking Elixir 300: Celebrating 300 with José Valim

Episode 300 of Thinking Elixir. It’s Episode 300 — a milestone just under 6 years in the making! To celebrate, we kick things off with a fun song, then dive into the news: the Localize library v0.15.0 brings locale-aware formatting and Unicode CLDR data to Elixir without any compile-time code generation, a new library called Reach builds program dependence graphs for Elixir and Erlang to help coding agents and static analysis tools understand your codebase, Tidewave gets exciting updates including voice input with click-to-add context and the ability to install it as a PWA, the ErlEF has opened its 2026 board elections with voting running May 8-15, and more! Then we sit down with José Valim for an in-depth interview covering Elixir v1.20, the latest progress on the set-theoretic type system, the story behind Tidewave, and how AI is — and isn’t — changing development on Elixir itself.

https://www.youtube.com/watch?v=m5DVazRVcXM