Senior Backend Engineer

cozycozy; Paris; Sur place; EUR 55 000 - 75 000; Plein temps

Résumé du poste

Une startup innovante, cozycozy, recherche un Ingenieur Backend Senior pour rejoindre son équipe technique à Paris. Le candidat idéal aura plus de 7 ans d'expérience et une expertise en TypeScript et Python, avec un rôle clé dans la conception de systèmes backend évolutifs pour servir des millions de voyageurs. Un environnement dynamique et international vous attend, avec des projets passionnants à développer.

Prestations

Assurance santé avec Alan

Café/thé et collations illimités

Environnement de travail stimulant au sein d'une équipe internationale

Qualifications

• 7+ ans d'expérience en tant qu'ingénieur backend ou full-stack (orienté backend).
• Maîtrise des langages backend modernes comme TypeScript et Python.
• Connaissance approfondie des bases de données relationnelles et non relationnelles.

Responsabilités

• Gérer le cycle complet des fonctionnalités backend, de la conception technique au déploiement.
• Concevoir et maintenir des microservices et API évolutives.
• Optimiser les performances et l'intégrité des données à travers les bases de données.

Connaissances

TypeScript

Python

REST/gRPC APIs

Microservices architecture

Performance tuning

Async code

Description du poste

About cozycozy

Cozycozy is the only search engine that gives you real-time access to all available vacation accommodation. Whether you're searching for a hotel, apartment, cottage, villa, or even a treehouse, our platform features over 20 million listings from more than 100 booking sites. You will find popular options like Airbnb, Booking.com, Gîtes de France, hotels.com, and Expedia, as well as plenty of unique services to explore, such as Agriturismo, Onefinestay, Belvilla, Sonder, Travelski, and many others.

Experiencing rapid growth, we are now present in over 50 countries in 20 languages, with offices in Paris and Budapest. You’ll be part of an international team (with 12 nationalities represented) that’s passionate about travel and innovation. By joining cozycozy, you’ll have the opportunity to make a real impact by helping millions of travelers worldwide find their perfect accommodation!

As a Senior Backend Engineer at cozycozy, you’ll work with our tech team to design and build fast, scalable backend systems that keep millions of travel searches running smoothly. You’ll write clean, high-quality code and take part in continuously evolving our features based on real user needs. From architecture to deployment, you’ll help build solutions that serve millions of travelers worldwide.

Main Responsibilities

• Own the full lifecycle of backend features, from technical design to production rollout

• Design, build, and maintain scalable microservices and APIs

• Optimize performance and data integrity across relational and non-relational databases

• Integrate AI/ML models into production workflows

• Support data engineering efforts across business intelligence and data pipelines

• Contribute to infrastructure decisions focused on scalability, efficiency, and cost optimisation

• Troubleshoot production issues, participate in peer reviews, write meaningful tests, and maintain up-to-date documentation

Requirements

• 7+ years as a backend or full-stack engineer (backend-focused), preferably in startups or scale-ups

• Fluency in modern backend languages like TypeScript and Python

• Experience with REST/gRPC APIs, OpenAPI standards, and microservices architecture

• Deep knowledge of relational (PostgreSQL, MySQL, DuckDB) and non-relational (MongoDB) databases

• Familiarity with validation libraries (Zod, Yup, Pydantic) and testing tools

• Solid understanding of performance tuning, async code, and messaging systems (e.g., FIFO, dead-letter queues)

• Experience in bare-metal and/or hybrid cloud environments

• A product mindset — you think in terms of user impact, not just code

• Fluent in English

Bonus points

• Exposure to AI/ML model integration or related infrastructure

• Familiarity with runtime performance optimization and performance/load estimation in production systems

• Familiarity with geolocation data, GIS systems

• Experience in the travel tech space or with large-scale search platforms

Our Full Technology Stack

• Programming: Node.js, Angular, TypeScript, Python, Golang, RxJS, HTML, CSS

• Databases: MongoDB, MySQL, PostgreSQL, Redis

• Infrastructure & Other Tools: Linux, Kubernetes, Docker, Gitlab, Jenkins, Grafana, Jupyter, RabbitMQ, Google Pub/Sub, Airflow, Spark, Prometheus

Why join cozycozy?

• The opportunity to play a key role in the development of a fast-growing startup.

• A stimulating work environment within an international team.

• A strong entrepreneurial culture, with numerous projects to imagine and lead.

• Office located in the heart of Paris (75010, Gare de l'Est) with unlimited coffee/tea, drinks, and snacks.

• Health insurance with Alan and a Swile card.