Luc Delmon

I've been self-training on AWS and Terraform, working on a personal project where I built the infrastructure for a classic Rails API. This included setting up comprehensive network security and automating deployment processes. In parallel, I've been expanding my knowledge of React and TypeScript, focusing on building modern, dynamic web applications

I joined Rail Europe as a Ruby back-end engineer to assist with the integration of those train providers and enhance the overall functionality of the back-end product, which involved developing on the internal Ruby gem that abstract each provider's API specifications and contribute to enhancements of both the end customer functionalities and admin features of the main website. Despite being a freelancer, I seamlessly integrated into the team, actively participating in reviews, following the board and priorities, and engaging in various subprojects. I also invested a significant portion of my the mission on a project focused on integrating a new payment provider.

The team was diverse, with members spread across different time zones and using english as a working language. This setup posed challenges in both technical work and communication because many actors could affect or be affected by a feature. Keeping a focus on engineering and council was crucial, especially since the company had recently undergone significant organizational changes, and many team members were new to the project.

At first my work was focused on communications with external API. Improving wrappers or debugging issues with them. I also worked on subject quite close to product to improve the offers (the number of differents train journeys that could be offered). This included updating configuration or working with the train stations inventory with specialist. At some point I was assigned to a bigger project aiming at switching the payment provider of the B2C website (from Braintree to Checkout). This got me deep into the payment related problematics as well as the fraud topic. Due to the knowledge I won from this I was then working mostly on payments issues (improvement, additions of many metrics, data analysis).

First part of the mission was to rewrite entirely the Airbnb wrapper (declared as a lib inside the main project) used to push and pull things on Airbnb using their Developer API. After some analysis and research on best practises I rewrited it during the first 2-3 weeks using a client and resources approach and also managed to unlock a testing ground from Airbnb that would become crucial to QA the refactoring that came next.

Second part of the project was to design a system to encapsulate the synchronisations between Hostfly servers and external platforms, with a better error management (rate-limit, critical errors or unprocessable requests) and an easy monitoring. After a bit of research and some brainstorming, we created a system using a dedicated pgSQL table and Sidekiq middleware systems.

Last long step was to rewrite every singular synchronisation into our new asynchronous system while improving file management, code organisation and adding a lot of tests. It was also a time to exchange with other teams using the product to provide or improves features. At the same time since I built some knowledge on the codebase I was able to help on bugs or small improvements not necessary linked with original mission. We also designed a visual representation of the synchronisation process on the website for better monitoring and added some documentations.

This first freelance mission reinforced my will to stay a freelance. I was given a lot of liberties and the "project approach" allowed me to do something clean using my engineering background without rushing for results but instead aiming for durability.

It was also interesting to work this specifically on using external APIs as it's a critical problematics for a lot of business. I hope to be able to use this knowledge and the one I got on sidekiq in a future mission.