its-just-beam

The Zen of Erlang ↗

post

ferd.ca · February 2016

Explains how OTP supervision trees encode recovery strategies as explicit architectural decisions, not afterthought error handling
Distinguishes between errors (expected, handle inline) and failures (unexpected, let the process crash and restart clean)
“Let it crash” requires pre-planned supervision hierarchies — the crash is intentional, not accidental

project

elixir-lang.org · 2012

Functional language built on the BEAM that adds modern ergonomics (macros, protocols, mix tooling) without sacrificing Erlang’s runtime guarantees
Processes are the unit of isolation and concurrency — each is a lightweight actor with its own heap, communicating only through message passing
The language design enforces the “let it crash” philosophy by making processes cheap and supervision trees idiomatic

framework

phoenixframework.org · 2014

Web framework for Elixir that exploits BEAM’s concurrency model to handle massive numbers of persistent connections (channels, LiveView)
LiveView eliminates the SPA/API split by rendering server-side HTML and pushing diffs over WebSockets — real-time UIs without JavaScript frameworks
Each request and each WebSocket connection runs in its own BEAM process, inheriting fault isolation and preemptive scheduling for free

paper

Joe Armstrong, PhD Thesis · December 2003

Joe Armstrong’s PhD thesis defining the principles behind Erlang/OTP: concurrency-oriented programming, process isolation, and error recovery through supervision
Argues that reliable systems must be built from unreliable components by isolating failures and encoding recovery strategies declaratively
Introduces the six rules of Erlang: isolation, everything is a process, error detection across processes, fault detection is built-in, processes can be upgraded, and failures are handled by other processes

project

GitHub · 2017

Deep dive into BEAM virtual machine internals: schedulers, memory management, garbage collection, and the process model
Explains how the BEAM achieves soft real-time properties through preemptive scheduling based on reduction counts, not time slices
Essential reference for understanding why BEAM processes are cheap (< 1KB initial heap) and how the VM enables millions of concurrent processes

talk

YouTube / Ericsson · 1990

Ericsson’s original promotional video for Erlang, demonstrating live telephony system upgrades without dropping calls
Shows hot code swapping in action — a running telecom switch is updated mid-call, seamlessly transferring to new modules
A time capsule of the problems that shaped BEAM’s design: five-nines uptime, concurrent call handling, and zero-downtime deployments