Software Engineer (M/F) - CDI - Paris Wiremind

Since 2014, Wiremind has established itself as a tech company transforming the transport and events industries with a 360° approach combining user experience (UX), software and artificial intelligence (AI).

Our expertise lies primarily in optimizing and distributing our clients’ capacity. We work on a wide range of projects such as demand forecasting and ticket pricing, 3D optimization of air freight or competitor price scraping. Our applications are go-to tools for companies such as SNCF, United Airlines, Qatar Airways or PSG, which use them to visualize, analyze and optimize their capacity.

Dynamic and ambitious, we are committed to preserving our technical DNA, the true engine of our success. Self-financed for more than 10 years, we have just raised our first funds to accelerate. The company is mainly made up of engineers and experts and keeps developing its business model based on Software-as-a-Service (SaaS) solutions.

As a Software Engineer, you will join the team behind Cayzn, our Revenue Management solution. To give you an idea of its scale:

Every year, more than 300 million passengers travel by train, plane or bus at a price driven by Cayzn. Behind the scenes, our machine learning models recommend prices, and our systems execute 28 million business rules and process more than 2 million pricing decisions every day.

This is the system you will work on, in production.

📌 Permanent contract (CDI) · Hybrid: 2 days of remote work per week · ASAP

Your missions 🚀

As a Software Engineer, you will take part in the development of new Cayzn features. With the support of our Product Experts and Data Scientists, you will help solve the business and technical challenges faced by our clients, mainly railway companies, airlines and bus operators.

In practice, even though no two days are alike, you will:

• Develop new features for our users, with a strong focus on code quality, alongside senior developers.

• Take part in maintenance, application monitoring and infrastructure management: you own what you ship, all the way to production.

• Reduce technical debt, propose new solutions and challenge architecture choices to continuously improve the codebase.

• Exchange daily with our product team to share your ideas for improving Cayzn and deepen your understanding of our clients’ needs.

Your first projects could be

• #1 – Make the pricing pipeline cheaper to run: "Cut the memory and CPU cost of the nightly pricing pipeline. A recent project removed redundant price history and reduced worker memory by 30–40% on our largest clients, measured in production."

• #2 – Let revenue managers steer the optimisation. "Give revenue managers control over the price recommendations of each train: a target booking curve, a fixed strategy, or steering applied at the next optimisation run. The work goes from the database model through the optimisation engine to the API."

• #3 – Bring bookings into the analytics in real time. "Stream bookings and ancillary sales into our ClickHouse data warehouse, so that clients' dashboards refresh during the day instead of after the nightly batch."

Our tech stack

• Backend: Python, SQLAlchemy, Remoulade, Flask

• Frontend: TypeScript, Angular, NGRX, D3.js, Next.js

• Databases and storage: PostgreSQL (several terabytes), Elasticsearch, Redis, Clickhouse

• Continuous integration and delivery: GitLab, ArgoCD

• Infrastructure: Kubernetes

• Monitoring and operations: Prometheus/Grafana and Kibana

Some figures: ~13 commits merged per day, ~ production release per week, 20 isolated client environments in production (81 environments in total) on Kubernetes, all deployed using GitLab and ArgoCD."

Your profile 🔍

• At least one internship in backend development in a production environment

• You have solid experience with Python (or another backend language) and a good command of relational databases.

• You write clean, tested and maintainable code, and you enjoy evolving an existing codebase.

• You already use AI in your development workflow and are curious to push its use further.

• You can take an ambiguous topic and move it forward autonomously.

• You can clearly explain a technical concept to a non-specialist, as you will work closely with complex business domains (pricing, distribution).

What will make the difference: experience with high-volume systems, an interest in design and UX, or open source contributions you are proud of.

Our benefits 🤌

By joining us, you will be part of:

• A historically self-financed startup with a strong tech identity, which has just raised its first funds to accelerate its growth! 🧬

• Beautiful 800 m² offices in the heart of Paris, boulevard Poissonnière ✨

• Attractive compensation, indexed on performance 💪

• A caring and stimulating team that encourages skills development through initiative and autonomy

• A learning-friendly environment with growth opportunities 🧑‍💻

You will also benefit from:

• A hybrid policy: 2 days of remote work per week and the possibility to occasionally work from abroad 💻

• Access to WellPass at a preferential rate to take care of your well-being 🏀

• A great company culture: monthly afterworks, regular meetups around tech and products, annual off-site seminars and team building activities…

Our recruitment process 🤞

1. A first call with Yasmine, our Talent Acquisition Specialist

2. A technical test or case study to prepare

3. A final interview with a manager at our offices to discuss your technical test or case study and meet the team

Wiremind is committed to equal opportunity, diversity and fairness. We encourage everyone with the necessary experience and skills to apply to our job offers.