r/erlang

Hey all 👋

Sharing a heads-up about Code BEAM Europe 2026 - 21-22 October in Haarlem (PHIL), plus online, with a training day on 20 October.

2 days, 2 tracks each day, and 3 keynotes - including Brooklyn Zelenka (Let It Disconnect: A Local-First Future), Sam Aaronof Sonic Pi (Notes on the Synthesis of Time, plus an interactive evening Phone Orchestra), and more.

~30 speakers across Erlang, Elixir and Gleam: ElixirConf®

The thing we're most excited about this year is the new Informal Space - a community-led area running alongside the main programme for the stuff that doesn't fit the talk format. Think hands-on demos, live experiments on real hardware, hacking sessions, games, panel-style discussions, talks in languages other than English… and at least one surprise we're not spoiling yet 🙂

We're finalising the Informal Space lineup now and will announce it soon. Newsletter subscribers get the first look(they already have), so if you don't want to miss it - and the other bits we'll be dropping between now and October - that's the place to be: Code BEAM Europe

Early bird tickets are limited - available for a limited time / until they sell out - so if you're planning to come, worth sorting sooner rather than later.

Register: Code BEAM Europe

See you in Haarlem or online!
The Code BEAM Europe Team

Just released ExDataSketch v0.10.2. This release contains mostly minor fixes and documentation updates. Here are the main changes:

• You can now set per-family default options (backend, precision, capacity, etc.) once via Application config instead of passing them at every call site.
• FilterChain.put_many/2 batches inserts through each stage's own batch path instead of looping single-item calls, and along the way we also caught and fixed a genuinely funny bug where Bloom.put_many/2's "optimized" batch path (an Erlang-tuple mutation trick that doesn't actually get the destructive-update optimization it was counting on) was slower than just looping single inserts — that's now ~25x faster and finally does what it always claimed to.
• On top of that: Cuckoo no longer spuriously reports full well below its designed load factor (a kick-eviction cycling bug),
• Quotient/CQF membership checks no longer decode the entire table on every call (up to 300x faster),
• CQF now correctly reports {:error, :full} instead of silently dropping inserts,
• and REQ gets the same compaction weight-invariant fix KLL got last release.
• Finally the livebooks have been tested, fixed and updated.

Two small breaking API changes: CQF.put/2/put_many/2 now return {:ok, cqf} tuples (mirroring Cuckoo), and FilterChain.delete/2 now returns a bare struct instead of a pointless {:ok, _}.

Full changelog and upgrade notes in the repo.

• GitHub: https://github.com/thanos/ex_data_sketch
• hex.pm:https://hex.pm/packages/ex_data_sketch

New BEAM There, Done That with the author of Bandit - the pure Elixir web server now default in Phoenix. Covers the HPACK debugging nightmare, what one-process-per-connection actually buys you at 3am, and why there's an AI-generated HTTP/3 PR sitting open on the repo that Mat hasn't merged.

He uses agents for everything in his day job. Bandit stays handwritten. The episode is honest about why.

https://youtu.be/XXQcoz_dTE0

New BEAM There, Done That with Maxim Kharchenko, creator of LING - a from-scratch Erlang VM running directly on Xen with no Linux kernel.

The part I hadn't seen discussed before: Ling's instruction set isn't fixed. It analyzes real OTP source, identifies frequently occurring patterns, and generates specialized opcodes - if loading the constant 17 is common enough, 17 gets its own instruction. More opcodes means a bigger VM and slower dispatch, so a heuristic manages the tradeoff.

Also: every allocation in the codebase has an explicit out-of-memory handler. Not convention - a whole-system discipline.

Francesco notes the problems Ling solved ten years ago have come back as unikernels and eBPF. Is anyone here doing bare-metal or near-bare-metal BEAM deployments today?

https://youtu.be/ILEyncf194M