Alex Koutmos on Elixir for Finance, Trading & Blockchain
Notas do episódio
Brex runs on Elixir. Klarna runs on Erlang. Mastercard is believed to use it. And most of the community that builds on these systems watches them with PromEx - a library written by today's guest.
Alex Koutmos has been in the Elixir ecosystem for over a decade. He wrote PromEx - the Prometheus metrics library most of this audience runs in production - and he's just written Elixir for Finance with his brother Dimitrios, a tenured finance professor at Texas A&M. The book takes Livebook, Explorer, NX, and Scholar and points them straight at markets, trading strategies, and blockchain infrastructure.
Topics include:
why switching money and routing a stock order are the same problem as switching a phone call - and why the BEAM was built for both
the ISO 8583 protocol story: 100 lines of C per message frame, dropped to 10 in pure Erlang, dropped to 4 with the bit syntax - and why nobody talks about this
Explorer as an Elixir wrapper around Polars (a Rust data frame library) - why the BEAM delegates the heavy compute and keeps the orchestration
how to use Livebook, NX, and Scholar to backtest a moving average crossover trading strategy without leaving Elixir
why "let it crash" doesn't mean "let the money vanish" - and exactly how a ledger, Oban, and durable event storage keep the truth safe across process restarts
the difference between a ledger and a database - and why a bank built on plain Postgres misses the point
blockchain as a distributed ledger: the same distributed state problem the BEAM community was chewing on long before Bitcoin existed
why fintech companies use Erlang and Elixir as a competitive advantage - and tell nobody
BlockScout, Aeternity, and where BEAM languages already run in blockchain infrastructure
what the Python and JVM financial tooling stacks miss that Explorer and NX cover - and where they still win
Recorded August/September 2026.
Resources mentioned:
Elixir for Finance - the book
PromEx on Hex
BlockScout - open source Ethereum explorer written in Elixir
Aeternity - blockchain built in Erlang