Doors open, Registration & Editor Setup

Beginner Reason & ReasonReact Workshop

Advanced ReasonReact Workshop

Reason & GraphQL Workshop

OCaml Workshop

Afternoon Workshop Block


Doors open & Registration
Coffee break

At Ubisoft Club we rewrote our application from Ionic / Cordova to React Native / ReasonML. As we all were Javascript developers, the transition was difficult, both technically and humanly. We implemented some fancy features using e.g. Storybook and GraphQL. But we had to pay the price of immature bindings, bundler issues…

We would like to share this experience with you, including the best and the worst of it.

At, we build mission-critical apps and services for the Public Transport and Public Safety industries. In 2018, we moved all our frontend development (web and React Native) to ReasonML.

As a case study about ReasonML in a finished product / client project, we present “Written Order”, a web app for Railway Safety. The app is an intelligent assistant for manual processes in train signalling, helping the signaller to ensure it is safe for the train to proceed.

Based on an interpreter for a check list definition language, it presents the signaller a series of simple questions to guide him/her through complex, deeply context-dependent check lists, generating a filled out “Written Order form” image on the way. The app authenticates against the customer’s Active Directory service and is fully offline-capable, yet still runs in Internet Explorer 11.


Jane Street is a long-time user of OCaml and the largest industrial user of the language. Today, there are hundreds of people at Jane Street who use OCaml to build rich and complex applications that are essential to our business.

In this talk, I’ll discuss the work we’ve done to provide those people with a great development experience as they write, maintain, and deploy software. I’ll also discuss Jane Street as an example of how OCaml can contribute to a tech-focused company’s success, both in the short and long term.

Not everyone is of the “Early-Adopter” Personality. Many of our coworkers don’t care if things are technically “better” or fancy language features that help them to remain “safe”. Understanding the different personality types helps us know how we can all get ReasonML to “jump the gap” to more mainstream languages and help our more pragmatic co-works understand why ReasonML is something they should devote time to learn.

Coffee break

I have been diagnosed with ADHD late in life (2 years ago). This opened my eyes to a journey through challenges and hardship I have not been able to comprehend were even affecting me up to that point. My talk is focused on these challenges and how Reason in particular helps me deal with them in my daily workflow.

Details will be announced reasonably soon!

Coffee break

For stroke patients, there is a saying “time is brain”. First responders need to assess patients as accurately and as quickly as possible, and then it’s off to the races to the best treatment centre. This is a high stakes situation where problems arising of both the human and software variety is ideally zero. Losing a loved one because “undefined is not a function” is certainly not ideal.

It should not be a surprise that eliminating the occurrence of such software defects in such a high stakes application is of paramount importance. We recently rewrote the core of our first responder stroke triage mobile application in ReasonML and Bucklescript to achieve the necessary safety guarantees that only the ML family of languages can provide. In this talk, I share details of how we undertook this task and lessons learnt along the way.

ReasonML is a hybrid of Javascript and Ocaml - traditionally 2 different pools of candidates. Have you ever wondered what the best of both worlds is like? Learn how ReasonML has improved the quality of our candidates letting us focus more time on the product and less on hiring.

After Party at Luftburg sponsored by Jane Street


Doors open
Open Stage
Dojo with the Ahrefs Team and Benjamin San Souci
Gathering at the Weinhof Zimmermann (Neustift am Walde)