Erlang Study Notes

Atoms and Terms

Understanding Erlang's atom data type and how atoms, numbers, tuples, and lists combine to form Erlang terms.

Binary Pattern Matching

Erlang's bit syntax lets you construct and deconstruct binary data with precise, declarative pattern matches, making it a natural fit for parsing network proto…

Building a Chat Server in Erlang

A hands-on walkthrough of building a TCP-based multi-user chat server in Erlang, covering gen_tcp sockets, one process per client, a broadcasting room process,…

Erlang and Distributed Systems

Explore how Erlang nodes connect, communicate transparently, and stay resilient across a distributed cluster.

Erlang and Mnesia

Understand Mnesia, Erlang's built-in distributed database, its table types, transactions, and how it fits into OTP applications.

Erlang and Rebar3

Learn how Rebar3 standardizes building, testing, and dependency management for Erlang projects.

Erlang Best Practices: Supervision, OTP, and Fault Tolerance

A practical guide to writing production-grade Erlang: let-it-crash supervision design, correct gen_server callback usage, ETS-backed shared state, precise erro…

Erlang Interview Questions

A guided walkthrough of the Erlang concepts interviewers probe most — the actor-model concurrency system, OTP fault tolerance, pattern matching, and distributi…

Erlang Quick Reference

A cheat-sheet tour of Erlang's core data types, common built-in functions, the shell/module workflow, OTP gen_server callbacks, and the pattern-matching idioms…

Erlang vs Elixir: Comparing the Two BEAM Languages

A practical comparison of Erlang and Elixir — how they share the BEAM VM and OTP, where their syntax and tooling diverge, and how to choose between them.

Error Handling in Erlang

Erlang handles failure through a distinctive combination of try/catch exception handling and the 'let it crash' philosophy, where supervisors, not defensive co…

ETS Tables

ETS (Erlang Term Storage) provides fast, in-memory tables for sharing large amounts of data between processes without the overhead of message passing.

Fault Tolerance: Let It Crash

Explore Erlang's 'let it crash' philosophy — why defensive programming is often avoided in favor of fast failure and supervisor-driven recovery.

Functions and Modules

A practical guide to organizing Erlang code into modules and functions, covering declarations, multiple clauses, arity, and exporting a public API.

gen_server Behaviour

Master the gen_server OTP behaviour — the standard pattern for building stateful, message-handling server processes with synchronous and asynchronous calls.

Guards and Clauses

How Erlang guards extend pattern matching with safe boolean conditions to express multi-way branching without if/else.

Higher-Order Functions in Erlang

How Erlang treats functions as first-class values, enabling anonymous funs, closures, and the standard library's map/filter/foldl.

Hot Code Reloading

Understand how the BEAM VM loads new module versions into a running system without downtime, and how to do it safely.

Installing Erlang

How to install Erlang/OTP on macOS, Linux, and Windows, verify the installation, and manage multiple versions.

Lists and Tuples

A comparison of Erlang's two core compound data types — lists and tuples — and when to reach for each.

Maps in Erlang

Maps are Erlang's key-value associative data structure, offering dynamic keys, efficient lookups, and pattern matching without requiring a compile-time schema…

Pattern Matching in Erlang

How Erlang's = operator, function clauses, and guards use pattern matching to bind variables and control program flow.

Processes and Message Passing

Learn how Erlang's lightweight processes communicate exclusively through asynchronous message passing, forming the foundation of concurrent, fault-tolerant sys…

Records in Erlang

Records give named, compile-time-checked structure to tuples, making Erlang code more readable and less error-prone when working with structured data.