Johanna Larsson

Contributed to Elixir core that one time

Johanna is a polyglot developer working with anything from edge computing to data processing pipelines. Outside of work she's a co-organiser and frequent speaker at the Malmo Elixir meetup and spends a bit too much time on the Elixir slack.

Past Activities

Johanna Larsson
Code BEAM Lite Amsterdam
28 Nov 2019
14.00 - 14.20

String processing optimisation

Using an underperforming string processing script as an example, this talk demonstrates how small changes can have considerable effects on performance in regards to execution time, but also memory usage and maintainability. Going from a simple but elegant version, Johanna will incrementally improve it and reach a 10x improvement, without losing the structure and flow or significantly impacting the number of lines required.



You will learn about some of the "fast" parts of Elixir, and how even though the language focuses on sensible defaults, there are always options when those defaults are not enough.



Anyone curious about badly performing Elixir code or how the language lends itself to string processing.

Johanna Larsson
05 Mar 2020
13.45 - 14.30

Diffing Hex packages

The tech industry is extremely dependent on open source packages. But every dependency you rely on is also a vulnerability. Multiple high profile packages across platforms have been hijacked and modified with malicious code.

This talk is about the value of auditing dependency updates and the tooling to make it less of a chore, including the introduction of a web-based diffing app and other tooling that helps you create an effortless auditing process.






Spread awareness about dependency management, and the importance of auditing code. Johanna will also discuss how tooling can make this less of a chore. Security should be easy.


Anyone who works with software.

Johanna Larsson
Code Elixir LDN
18 Jul 2019
11.10 - 11.30

Performant String Processing Scripts in Elixir

Can you write a performant string processing script in Elixir? Incrementally optimizing a simple implementation while introducing many interesting parts of Elixir, including ETS, and iolists, we end up with a 10x speedup over the original implementation. With a little bit of knowledge, Elixir becomes a viable and performant scripting language, and this also carries over into other data processing tasks.


Showing off some of the "fast" parts of Erlang/Elixir.


Anyone who has ever thought about optimization or is curious about the parts of Erlang/Elixir that make your code go faster.