Contract FastAPI Engineer (3-6 Months)

Are you looking for a pioneering team that embodies a culture of continuous testing and learning, enabling you to truly pursue your ambitions? Look no further! At SFEIR, your career progression is in your hands—whether you want to advance vertically, horizontally, or across different domains. Your PlaygroundTech Stack: Python, FastAPI, Docker, Kubernetes, TDD.SFEIR AI: A dedicated path to mastering generative AI and agentic coding.Community: 140 Google Cloud certified experts, 30 Google Authorized Trainers, 7 Google Developer Experts. Your ResponsibilitiesDesign and develop robust, high-performance, and scalable APIs using Python and FastAPI.Ensure code excellence through unit and integration testing, TDD, and active participation in code reviews.Architect Cloud-Native services (primarily GCP) using Serverless or containerized approaches (Kubernetes, Docker).Contribute to the industrialization of our products by developing CI/CD strategies and implementing DevOps practices (GitHub Actions).Integrate AI/GenAI solutions to transform complex business processes.Ensure the smooth operation of applications in production (observability, monitoring, performance optimization). Your ProfileYou have at least 4 years of experience in Python development.Proven expertise in FastAPI and REST API architecture.Strong proficiency in Cloud environments (GCP/AWS) with experience in Serverless architectures.A keen understanding and adherence to coding best practices (TDD, code reviews, Clean Code).Curiosity about Generative AI and new technologies. Why Join SFEIR?Every Sfeirian is supported by an Engineering Manager.Opportunities for career advancement into Staff Engineer, Principal Engineer, or Engineering Manager roles.Continuous training with access to Google Cloud Skills Boost.

AllegoAt Allego, we are at the forefront of accelerating the transition to clean electric mobility across Europe. As a leader in electric vehicle (EV) charging infrastructure, we make sustainable transport accessible for everyone. Our solutions empower drivers to recharge their vehicles effortlessly and confidently, providing a seamless experience tailored to their needs.Our mission is to contribute to zero-emission mobility, ensuring that every driver finds the right solution, in the right place, at the right time.The EV market is evolving rapidly; the journey ahead is exciting, and we are moving forward with ambition and confidence.About the PositionAllego is seeking a Software Engineer to play a vital role in developing our internal energy trading platform. This engineering-focused position involves the following responsibilities:Collaborating closely with operational teams to translate business requirements into reliable and secure solutions.Managing the entire development cycle: specifications, architecture, coding, testing, production deployment, and operational maintenance.Designing and maintaining the technical architecture of the platform and its ecosystem.Implementing data flows for incoming and outgoing interactions with other market players in the energy sector.Being comfortable with the implementation of new protocols and integrations (API, FTP, VPN, certificate connections, etc.).This position requires the ability to be on-site at our Paris office once a week.

Your ImpactJoin our dynamic team as a Senior Software Engineer in the AI Health Companion division, where your expertise will help us revolutionize healthcare. You will play a crucial role in evolving the Doctolib application into a comprehensive health companion powered by artificial intelligence, enabling patients to manage their health with precision and compassion.Your primary responsibility will be to collaborate within a feature team to develop an AI-driven chat interface designed to address patients' inquiries regarding their health and the health of their loved ones. Your contributions will directly enhance the experience of healthcare teams and patients alike.

Who Are We?At MARGO, our consultants focus on what truly matters: tackling complex projects that combine intellectual challenges with real business impact. We partner with leading players in finance, industry, and tech to design and develop high-performance software solutions, including distributed architectures, cloud platforms, real-time systems, and large-scale critical applications.Why Join the Software Engineering Practice?You will be part of a team led by Paul Blois, our Practice Manager at MARGO for five years. Working alongside them means benefiting from extensive company knowledge, receiving close support in your professional growth, and contributing to demanding IT projects that have a significant impact on our clients.Your ResponsibilitiesYou will collaborate closely with research and business teams, enabling regular feedback and participation in various strategic changes. The goal is to transform, migrate, and optimize the tools we use.As a Python R&D Developer, your tasks will include:- Developing and adding new features using Python and C++- Participating in the redesign and optimization of various tools- Adhering to development standards and code quality- Implementing tests to reduce technical debt and improve Time to Market- Tackling technical challenges such as real-time processing, parallelization, and high data volumeYou will have the opportunity to grow in an agile and human-sized environment where technical excellence and coding best practices are at the heart of our activities.Technical challenges include algorithmic complexity, real-time performance, optimization, and scalability.Technical Stack: Back End: C++ and Python; Front End: JavaScript; Unix/Linux Environment.

Your ImpactJoin us as a Senior Software Engineer in our Patient domain. Your mission is to revolutionize the Doctolib application into a comprehensive health companion powered by AI, enhancing patient health management with precision, empathy, and safety. You will collaborate within a feature team to develop an AI-driven chat interface designed to address health inquiries from patients and their loved ones.Being part of the Doctolib tech team means creating innovative products and features that significantly improve the daily lives of healthcare providers and patients alike.

About UsAt MARGO, our consultants focus on what truly matters: engaging in complex projects that blend intellectual challenge with real business impact. We support the most prominent players in finance, industry, and technology by designing and developing high-performance software solutions, including distributed architectures, cloud platforms, real-time systems, and large-scale critical applications.Why Join the Software Engineering Practice?You will be part of a team led by Paul Blois, who has been the Practice Manager at MARGO for five years. Working alongside him means benefiting from an in-depth understanding of the company, receiving close mentorship in your career development, and contributing to demanding IT projects with significant impact for our clients.Your ResponsibilitiesYou will join a team of 12 professionals tasked with translating complex financial mechanisms into an elegant and resilient software architecture. At the heart of a leading energy company's market activities, you will design the contract modeling engine that manages the group’s risk exposure.As a Senior Python Developer, your challenges will include:- Architecture & Design: Developing and evolving APIs and microservices capable of modeling rich and varied contractual life cycles.- Engineering Excellence: Ensuring code quality and maintainability (Clean Code, extensive unit and integration testing) in an environment where even a minor miscalculation can have direct financial repercussions.- Domain Modeling: Collaborating with business experts to convert complex management rules (gas purchases, P&L tracking, European regulatory constraints) into high-performing data models.- Performance & Scalability: Optimizing services for the aggregation of massive data volumes necessary for real-time risk management tools.

About Allego Allego develops and operates EV charging infrastructure across Europe, supporting the shift to clean electric mobility. The company provides charging solutions for all types of electric vehicles, aiming to make zero-emission transportation accessible and convenient for drivers. As the EV landscape changes quickly, Allego continues to expand its network and technology with a focus on sustainability. Role Overview The Senior Python Engineer will help build and maintain Allego’s proprietary energy trading platform. This role centers on hands-on engineering and technical ownership, working with both internal teams and external energy partners. What You Will Do Develop and manage data flows between Allego and external energy partners. Integrate new protocols and systems, such as APIs, FTP, VPN, and secure certificate connections. Own the full software development lifecycle: gather requirements, design, develop, test, deploy, and provide ongoing support. Design and maintain the technical architecture of the trading platform. Work closely with operations to turn business needs into reliable technical solutions. Work Location This position is based in Paris, Île-de-France. In-person attendance at the Paris office is required once per week.

Join CAPFI, a consulting firm specializing in IT and Financial Markets, where we have a dedicated team focused on this strategic domain.Our consultants combine technical expertise, applied mathematics skills, and a deep understanding of financial challenges to work on high-impact projects, including:Project Management & Business Analysis in Financial MarketsFinancial Engineering (Front Office, Risk Management, R&D)Your Responsibilities As a Python Developer / Software Engineer, you will be integrated into an agile team and will work with our major clients (investment banks, asset managers, fintechs, etc.) on back-end or full-stack projects:Analyze technical architecture and validate proposed changesDevelop tools for data analysis and processingDesign and implement new features on modern infrastructuresAutomate testing (unit, integration, functional)Participate in user demonstrations and acceptance testingContribute to production releases in collaboration with DevOps and security teamsWeb and service development (FastAPI, Flask, Django, NGINX, Apache, etc.)Implement deployment and operational proceduresSet up and manage CI/CD pipelines (GitLab CI, Jenkins, Bitbucket, Ansible, Docker, etc.)Draft test plans and technical documentationYou Are the Right Candidate If:You thrive in a demanding, stimulating, and collaborative environmentYou are passionate about Python development and solving complex problemsYou possess strong technical knowledge (Python, testing, CI/CD, software architecture)You have a natural curiosity for Financial MarketsYou hold a degree from an engineering school or equivalent and have at least 3 years of experience in Python development within a structured contextWhat CAPFI Offers YouAt CAPFI, we place collective knowledge sharing and freedom of growth at the heart of our culture. We offer a flexible work environment, ...

Join our dynamic team at Iliad as a Backend Python Developer in Paris! We are looking for passionate and skilled individuals to contribute to our innovative tech projects. You will work closely with cross-functional teams to design and implement robust backend systems, ensuring high performance and responsiveness to requests from the front-end.Key Responsibilities:Develop and maintain server-side applications using Python.Collaborate with front-end developers to integrate user-facing elements.Optimize applications for maximum speed and scalability.Participate in code reviews and contribute to team knowledge sharing.Stay updated with emerging technologies and best practices.

About UsHarmattan AI is at the forefront of defense technology, specializing in the development of autonomous and scalable defense systems. Following the successful completion of a $200 million Series B funding round, which has valued our company at $1.4 billion, we are actively expanding our teams and enhancing our capabilities to deliver mission-critical solutions to allied forces.We are driven by our core values: creating technologies with meaningful impact, striving for excellence in all our endeavors, setting ambitious goals, and tackling the most challenging technical problems. Our work environment is dynamic and demanding, where rigor, accountability, and execution are paramount.About the RoleAs an Automation Software Engineer, you will be instrumental in designing and developing the software that powers our automated testing and inspection platforms. Within the R&D department, you will develop robust and scalable automation tools that enhance both product development and manufacturing processes. Your primary focus will be on software development for test automation, while also engaging in the integration of mechanical and electrical components of test systems.

Join us at iliad-free in Paris as a Staff Engineer specializing in Python. You will take on a pivotal role in our ambitious program aimed at modernizing and evolving our backend systems.Your primary responsibility will be to lead the technical direction of our information system backend, which manages all Free subscribers, including subscription processes, subscriber spaces, and additional services such as video streaming and mobile phone sales.In this role, you will develop a deep understanding of complex business processes executed by our system, such as billing for third-party services, subscription management, and fiber optic connections.You will guide the team in defining the architecture of this distributed system while actively contributing to development using Python, ensuring hands-on involvement.Your expertise will drive development practices that prioritize resilience, quality, testability, and speed of delivery. Additionally, you will be instrumental in establishing robust operational methods in a model where development teams manage their solutions in production, with a constant focus on performance and scalability.

Join Meritis as a Senior Python Developer / DevOps Engineer and become a key player in our dynamic team. We are looking for an experienced professional who is passionate about software development and cloud technologies. In this role, you will design, develop, and maintain robust Python applications while leveraging DevOps practices to enhance our deployment processes.

Join our dynamic team at iliad-free as a Staff Engineer specializing in Python development. We are looking for innovative and driven individuals to contribute to our impactful projects in the heart of Paris. This role offers a unique opportunity to work on cutting-edge technologies and collaborate with talented professionals in a vibrant work environment.

Join our dynamic team at Sunrise United States Inc. as a Python Back-End Developer. We are seeking a talented developer who is passionate about crafting efficient, scalable code and creating innovative back-end solutions. If you thrive in a collaborative environment and have a strong understanding of Python and back-end technologies, this is the perfect opportunity for you!

At Joko, we empower consumers to shop smarter and save money. Our mission is to transform the shopping experience, enabling individuals to make informed decisions about their purchases.Founded in Paris, Joko is a tech-driven company and a certified B Corp, boasting over 90 talented employees across Paris, Barcelona, New York, and beyond. Over 5 million users benefit from our services, saving money daily at more than 10,000 merchants through our platform.We offer a range of features, from cashback and automatic coupons to price alerts and carbon tracking, continually enhancing our products to facilitate smarter shopping. Currently, we are developing an AI-powered shopping assistant to help users identify the best products based on price, quality, and impact.Having achieved profitability in our primary market, we are now expanding globally, with a keen focus on the US market.Join us at the forefront of the shopping revolution! Our Engineering TeamOur Engineering team thrives on tackling advanced technical challenges with innovative solutions. With a strong emphasis on product design and innovation, they are shaping the future of shopping. Their goal is to positively influence the everyday lives of millions of users worldwide.As a member of the Engineering team, Software Engineers collaborate closely with the Product team throughout the entire process—from exploration and design to implementation and deployment. At Joko, we understand that teams composed of engineers with diverse skill sets, working in tandem with product teams, can deliver a truly delightful and innovative user experience.The Engineering team is rapidly expanding to continuously innovate across all facets of our product and technology stack, driving the transformation of online shopping. Your RoleAs a Growth Software Engineer, you will play a crucial role in scaling Joko's user and business growth through your coding expertise. Collaborating closely with the Product team, you will iterate quickly on key growth drivers—such as acquisition, retention, and engagement—as we expand into international markets, beginning with the US.You will work at the intersection of product and engineering, propelling the business forward within a dedicated cross-functional task force that includes key members from Marketing, Data, Business, and Product.Growth Experimentation: You will design, build, and deploy experiments across the entire user journey—from onboarding to retention—to drive significant results in key growth metrics.

Join dev2 as a Manager of Data Engineering and lead our innovative data engineering team. In this pivotal role, you will leverage your expertise in Python, AWS, Airflow, and Snowflake to design and implement robust data solutions that enhance our operational capabilities.As a key member of our leadership, you will be responsible for driving the strategic vision of our data engineering initiatives, mentoring a talented team, and collaborating with cross-functional partners to ensure data integrity and availability. This hybrid position offers the flexibility of remote work combined with the dynamic environment of our Paris office.

At Joko, we empower consumers to shop smarter, revolutionizing the shopping experience by enabling informed decisions and significant savings.Originating from Paris, Joko is a pioneering tech company and a certified B Corp with a diverse team of over 90 skilled professionals located across Paris, Barcelona, New York, and beyond. With over 5 million users benefiting from our services at more than 10,000 merchants, we are committed to enhancing the shopping experience.Our innovative offerings include cashback, automatic coupons, price tracking, and carbon footprint monitoring. Currently, we are developing an AI-driven shopping assistant to guide users toward optimal product choices based on price, quality, and environmental impact.Having achieved profitability in our primary market, we are poised for global expansion with a strong emphasis on the US market.Join us on this exciting journey to shape the future of shopping!This position is remote-friendly for candidates in France and Spain. Our Engineering TeamsAs a Software Engineer at Joko, you will engage with a variety of cutting-edge technical challenges and impactful projects. Depending on your skills and interests, your contributions could span key areas such as:Tech: Work alongside the Product team to innovate Joko's user-facing products, taking full ownership from ideation through to deployment. You'll tackle complex engineering challenges, such as developing AI-powered shopping assistants or creating scalable algorithms to analyze extensive data from e-commerce platforms worldwide.Operations: Collaborate with all teams at Joko by designing and implementing software solutions that enhance operational efficiency at scale. Projects may include building customer support systems, improving fraud detection, or developing AI tools to streamline team operations. Your ResponsibilitiesAt Joko, we value ownership and adaptability. You will take full responsibility for your projects, guiding them from initial concept to live deployment, ensuring excellence and innovation throughout. We seek versatile engineers equipped with a broad range of technical skills to tackle complex, cross-domain challenges. Your key responsibilities will include:

Alice & Bob is pioneering the development of the first universal, fault-tolerant quantum computer aimed at tackling some of the most challenging problems in the world. Our innovative quantum computer is based on a revolutionary type of superconducting qubit known as the Schrödinger cat qubit. Unlike traditional superconducting platforms, cat qubits possess the remarkable capability to autonomously implement quantum error correction!We are leading the quantum revolution, standing shoulder to shoulder with industry giants like Google and IBM, and we are rapidly expanding following our successful €100 million funding round in 2025 dedicated to advancing our unique technology.With over 100 talented individuals, including physicists, PhD students, engineers, and seasoned business professionals, we are united in our quest to achieve our ambitious vision. Are you ready to join us as a quantum pioneer and help reshape the future?About the Role:The Calibration Team is tasked with automating the calibrations of our Quantum Processing Unit (QPU) to maximize its performance and ensure its operational reliability. As a Senior Software Engineer within this team, you will be instrumental in architecting the automatic calibration software. You will collaborate closely with quantum scientists to develop, maintain, and enhance the calibration processes. Additionally, you will work alongside other software engineers across the organization to facilitate seamless integration of your team's software with other in-house software components.

About H H focuses on advancing superintelligence through agentic AI. The company’s mission centers on automating complex, multi-step tasks that people usually handle, aiming for AI agents to help realize the full range of human potential. H seeks talented AI professionals who care deeply about responsible and safe development, as well as technical progress in agentic systems. The culture values openness, ongoing learning, and teamwork. Every team member’s input matters here. Product Engineering at H The Product Engineering team develops H’s Enterprise Platform, which provides customers with tools and services for essential operational needs. This platform supports large-scale computer-use agents, manages complex workflows, and offers a suite for observability, troubleshooting, and evaluation. Product Engineering connects AI research with practical applications and works closely with teams across the company.