Every conversation, since episode one.

Part one established that Erlang scales. Part two is about what comes after - keeping a codebase that large healthy for years, when most engineers arrive having never written Erlang before.

Everyone quotes WhatsApp when the topic of Erlang and scale comes up. Fewer people know what it actually looks like from the inside - what was hard, what was never hard, and what the team spent their time on once the concurrency stopped being the problem.