Senior Full-Stack Developer - ReactJS/Redux at Altersolutions | Paris

Join Altersolutions as a Senior Full-Stack Developer specializing in ReactJS and Redux. In this pivotal role, you will leverage your expertise to design and implement innovative web applications, ensuring high performance and responsiveness to user interactions. Collaborating with cross-functional teams, you will drive the entire software development lifecycle, from concept through delivery.

Join Outsight, where our cutting-edge software transforms 3D LiDAR data into actionable insights for tracking the movement of individuals and vehicles. Our solutions are utilized by a variety of transportation hubs, including airports and train stations, as well as sports venues, road infrastructures, and industrial sites. We empower operators with precise and anonymous Spatial Intelligence data to enhance operational efficiency and ensure user safety and satisfaction. Our diverse team of experts, spanning across Paris, San Francisco, Sophia-Antipolis, and Hong Kong, is dedicated to advancing our innovative solutions. With a commercial office in Spain, we are committed to our global outreach. Discover more about us through this link: Insights about Outsight. Trusted by leading airports and train stations worldwide, our Passenger Flow Traffic Monitoring solution is a cornerstone of our offerings. Our Car Traffic Remote Monitoring product has also gained the confidence of Tier 1 clients, including BMW. Role Overview We are seeking a vital contributor to our Outsight Shift product suite. Our ecosystem encompasses real-time 3D monitoring of digital twins, live analytics, and decision support tools designed to optimize user management of people and vehicle flows. In this role, you will play a crucial part in architecting our application and frontend foundations to ensure scalability as our product capabilities expand. You will emphasize design, performance, usability, and maintainability while collaborating closely with product managers, data engineers, and scientists to deliver seamless user experiences.

About UsCryptoNext Security is a pioneering deeptech startup focused on post-quantum cryptography. We empower institutions and enterprises to navigate a future where quantum computing poses a threat to existing cryptographic standards. Our collaborations span major sectors including finance, defense, and telecommunications, as we deliver state-of-the-art, quantum-safe security solutions.Your RoleIn your capacity as a Full Stack Developer, you will play a key role in advancing DISCOVERY, our innovative observability and orchestration platform tailored for post-quantum cryptography operations.You will engage with the entire technology stack — developing backend services, managing data flows, and crafting frontend interfaces — while working closely with product, backend, and infrastructure teams.Responsibilities Design, develop, and maintain comprehensive full-stack features for the DISCOVERY platform. Create modern, responsive React front-ends that integrate seamlessly with Node.js and Kafka backends. Participate in architectural discussions and propose technical enhancements in line with our long-term product vision. Backend Development & APIs Design and implement efficient REST and event-driven APIs. Ensure optimal performance, scalability, and resilience across distributed components. Collaborate with backend engineers on domain modeling, API contracts, and data flows. Data Visualization & Observability Implement advanced data visualization and monitoring features using the ELK stack (Elasticsearch, Logstash, Kibana). Integrate backend logs, metrics, and analytics into user-friendly frontend dashboards. Engineering Standards Engage in code reviews and maintain high standards of engineering excellence. Contribute to technical documentation and advocate for software craftsmanship. Adhere to the KISS, DRY, SOLID principles, and embrace pragmatic engineering methodologies (“done is better than perfect”). DevOps & CI/CD Assist in deployment workflows, CI/CD pipelines, and automation initiatives. Work within Docker/Kubernetes environments to ensure smooth delivery of applications.

About Nabla Nabla brings together entrepreneurs, clinicians, and engineers with a shared goal: making clinical work more rewarding for healthcare professionals. The team partners closely with forward-thinking clinicians to build an AI assistant that streamlines documentation and supports patient care. Nabla’s platform is now trusted by over 100,000 clinicians in more than 130 healthcare organizations. With recent Series C funding of $70M, Nabla is growing its Paris-based team to develop the next wave of clinical AI. The company’s roadmap includes expanding features such as ambient listening, dictation, coding, and command tools, all aimed at improving both clinical and financial workflows. AI and Healthcare at Nabla Nabla’s rapid growth is built on three years of focused product development. The engineering team, including former Meta AI Research engineers, stays ahead of the curve in applying AI to healthcare. The company benefits from the guidance of Yann LeCun, Chief AI Scientist at Meta and Turing Award winner, who serves as an advisor. Engineering Culture Engineering at Nabla is lean, agile, and technical. Teams work across machine learning, desktop applications, and platform infrastructure to deliver AI solutions that can scale in clinical environments. How Teams Work Product development at Nabla happens in cross-functional squads. Each squad focuses on a specific product area and includes product managers, designers, engineers with varied backgrounds, and domain experts. High ownership and collaboration define the way these squads operate. Senior Full-Stack Engineers join a squad and contribute to a focused part of the product. What You Will Do As a Senior Full-Stack Engineer in the Paris office, expect to play a key role in building and scaling Nabla’s AI-powered healthcare platform. The work covers multiple layers of the platform, integrating advanced technologies to improve both user experience and operational efficiency.

Join our dynamic technical team of around thirty professionals in a warm and fun work environment! You have the freedom to choose your preferred workstation setup, allowing you to work in the way that suits you best.Your day-to-day will involve tackling a diverse range of challenges, including API development, implementing new features, creating proofs of concept (POCs), and managing application maintenance (TMA).Our technology stack includes:NodeJs & ExpressJS;AngularJs, VueJs;MongoDB, Postgres;Kubernetes & Docker;AWS;

Join our dynamic team as a Web Developer specializing in Magnolia. In this role, you will leverage your skills to create and maintain innovative web solutions that meet our clients' needs. You will collaborate with cross-functional teams to deliver high-quality products while ensuring optimal performance and user experience.

Join Margo Group as a Full Stack Developer specializing in Java and React. We are seeking a talented and motivated individual to contribute to our innovative projects and help shape the future of our tech solutions. As part of our team, you will work closely with designers and product managers to refine our offerings and deliver high-quality software solutions.

Join our innovative team at myjobcompany1 as a Full Stack Web Developer. In this role, you will be responsible for designing and implementing robust applications that improve user experience and meet business needs. You will work with both front-end and back-end technologies, ensuring seamless integration and performance.

About the RoleMaki is revolutionizing the field of talent acquisition and management through innovative AI-driven solutions. As a Software Engineer, you will take charge of the entire lifecycle of our AI products, ensuring their success from conception to deployment.Lead Technical Initiatives: Oversee and execute technical projects with a holistic full-stack approach, ensuring an optimal balance between speed and quality.Develop Reliable Systems: Create systems that maintain effectiveness despite unpredictable components, harnessing AI agents in real-world scenarios.Utilize Cutting-Edge Technologies: Keep our technology stack at the forefront by incorporating the latest advancements in Large Language Models (LLMs), vision models, and agent architectures.Collaborate Across Teams: Work with various stakeholders to pinpoint user challenges and engineer immediate solutions that enhance user experience.Who You AreWe seek dynamic, product-oriented full-stack engineers eager to make a significant impact and embrace ownership in a streamlined, high-performance team environment. You should be:Autonomous: A self-starter who drives projects to completion and thrives in leadership roles.Innovative: Passionate about AI technologies and keen to actively apply them in your work.Foundational: Interested in contributing to a high-growth journey by shaping our technology and culture from the ground up.Our Technology Stack:Backend:Typescript, Python, PostgreSQL, Google CloudFrontend:ReactJS, Typescript, GraphQLIf you're enthusiastic about transforming the future of AI-driven hiring, we want to hear from you!Recruitment ProcessMochi Screening: Experience our product firsthand.Interview with Hiring Manager.Coding Assessment.System Design Interview.Final Interview with the CEO.

Join our innovative team that is reshaping the future of global living.At The Flex, we envision a world where renting a home is instant, intelligent, and effortless — as seamless as booking a ride. Our ambitious goal is to enable anyone to live anywhere, anytime, without friction.Utilizing Base360.ai, our proprietary automation engine, we’re constructing the operating system for modern renting — integrating property data, orchestrating operations, and facilitating seamless stays across continents.If you are passionate about technical ownership, system architecture, and building platforms that function at real-world scale, this role places you at the heart of how millions of people move, live, and interact with the world.

About UsAt CryptoNext Security, we are pioneers in the realm of deep technology, focusing on post-quantum cryptography. Our innovative solutions empower businesses and institutions to safeguard their data against the impending challenges posed by quantum computing. We proudly collaborate with prominent clients across sectors such as finance, defense, and telecommunications.Your Daily ResponsibilitiesCraft and implement dynamic user interfaces utilizing React for our advanced post-quantum cryptography products.Work collaboratively with Product and Backend teams to deliver a seamless and user-friendly experience.Enhance performance while ensuring cross-browser and cross-device compatibility.Integrate REST APIs to facilitate interaction with backend services.Engage in code reviews and uphold best practices, including unit testing, continuous integration, and comprehensive documentation.Propose enhancements to frontend architecture through technological upgrades and refactoring.Foster improvements in our products beyond your typical responsibilities.Adhere to our frontend team principles: “Done over perfect” / we prioritize speed: KISS, DRY (Don't Repeat Yourself), SOLID.Essential SkillsProficient in React / Next.js along with its ecosystem (React Hooks, Context API).Solid understanding of TypeScript and fundamental programming principles.Experience with modern UI libraries such as Tailwind or chadcn/ui.Proven track record in integrating REST APIs.Strong knowledge of frontend performance optimization and related tools (Webpack, Vite, Core Web Vitals).Familiarity with frontend testing frameworks like Jest, React Testing Library, and Cypress.Competence in Git, CI/CD pipelines, and DevOps for automated integration and deployment.Desirable SkillsExperience with gRPC.Understanding of secure coding practices and application security.Basic knowledge of cryptography and cybersecurity.Experience in a startup or deeptech environment.Join Our TeamYou will become a key member of our R&D team, collaborating closely with backend developers, product managers, and UX/UI designers. You will report to the team lead and work with various departments to develop high-performance, user-centric interfaces that align with our clients' needs.Application ProcessInitial conversation with our HR team to discuss your background and motivations.Technical interview to assess your skills and fit for the role.

Are you passionate about innovating in the tech world? Do you thrive on tackling intricate business challenges in a dynamic, collaborative, and inclusive environment? At Capital One, you will join an energetic team of innovators and problem-solvers committed to addressing genuine customer needs.We are on the lookout for Full Stack Software Engineers who are eager to integrate data with cutting-edge technologies. As part of the Capital One team, you will play a pivotal role in a significant transformation initiative.In this position, you will contribute to an enterprise-wide data management and governance application designed to oversee digital assets, including datasets, data stores, and applications across Capital One. This centralized repository will enhance the navigation, discovery, and management of digital assets, ensuring data security and compliance.

At The Flex, we envision a future where renting a home is as instantaneous, intelligent, and hassle-free as booking a ride.Our ambitious goal is to empower individuals to live anywhere, at any time, without the usual barriers.Driven by our innovative Base360.ai automation platform, we are crafting the ultimate operating system for modern rentals — seamlessly integrating property data, streamlining operations, and facilitating effortless stays worldwide.If you are passionate about web technologies, API-driven solutions, automation, and scalable operations, this is your chance to influence how millions navigate, reside, and engage with the world. What You’ll BuildAs a Full-Stack Engineer (Web & APIs), you will be responsible for designing, developing, and scaling the essential web applications and APIs that drive The Flex platform — enabling immediate bookings, smart access, automated workflows, and predictive operations.Your role will encompass all aspects of frontend design, backend development, and cloud infrastructure, transforming intricate operational hurdles into elegant, scalable, and API-centric solutions.You won’t merely deploy features.You will enhance efficiency, unlock automation, and lay the groundwork for a sophisticated, global rental network. Your MissionBuild the PlatformCreate fast, dependable, and scalable web applications and APIs that facilitate bookings, payments, availability, and guest interactions.Design API-First SystemsDevelop robust, well-documented APIs that connect Base360.ai to internal systems and external partners.Automate at ScaleConstruct event-driven services and automated workflows to eradicate manual processes across the organization.Connect the EcosystemImplement impactful integrations with partners including Airbnb, Stripe, Hostaway, and Twilio.Deploy with ConfidenceLaunch and maintain serverless infrastructure on AWS, optimized for speed, reliability, and global reach.Solve Real ProblemsAddress challenges such as real-time booking synchronization, pricing intelligence, keyless access systems, AI-driven alerts, and live operational dashboards.Build With PurposeWork closely with product, data, and operations teams to transform concepts into tangible, measurable outcomes.

Join Altersolutions as a Fullstack Developer specializing in .Net and Angular. We are seeking a dynamic individual who is passionate about building innovative web applications and enhancing user experiences.Your role will involve collaborating with cross-functional teams to develop and maintain scalable applications. You will have the opportunity to work with the latest technologies and contribute to exciting projects that make a real impact.

Join Altersolutions as a Product Owner and be at the forefront of driving innovation in product development. You will collaborate with cross-functional teams to define the product vision, manage the product backlog, and ensure that the final product meets customer needs and business goals.

UpSlide is the leading productivity and branding solution for financial services. Our innovative software significantly enhances the functionalities of PowerPoint, Word, Excel, and Power BI, enabling users from prestigious firms such as Citi, KPMG, and BNP Paribas to focus on high-value tasks rather than formatting or manual data entry. With over 160 employees, we are in a growth phase, with offices located in Paris (headquarters), London, New York, Singapore, and Berlin.Our Core Values Our values guide our approach to work and are central to our recruitment process. We seek individuals who resonate with the following principles:Excellence: Every detail matters, and we prioritize the quality of our deliverables.Trust: We are passionate, committed, and empowered to act autonomously.Well-being at Work: We maintain a positive outlook and share our enthusiasm with colleagues and clients alike.The Team ‍‍You will join the UpSlide development team, currently composed of 26 developers organized into 5 squads. Our missions for 2026 include:OfficeJS: Preparing UpSlide for the transition from Microsoft Office to Office JS.FA: Enhancing our product's superiority in the Financial Advisory sector.FA & AI: Strengthening our product's edge in Financial Advisory by focusing on AI-related solutions.IB & AM: Continuously improving our offerings for Investment Banking & Asset Management.Platform: Upgrading our infrastructure to support tenfold user growth.Join Us!

About Nabla Nabla brings together entrepreneurs, healthcare professionals, and engineers to restore the joy of practicing medicine. The team collaborates closely with innovative clinicians, applying advanced machine learning to build an AI assistant that strengthens the human connection in healthcare. By streamlining clinical documentation, Nabla helps providers focus on patient care. Today, more than 100,000 clinicians from over 130 healthcare organizations use Nabla to support their daily work. With $70M secured in a recent Series C round, Nabla is expanding to advance clinical AI and improve experiences for clinicians and patients worldwide. The company is currently developing a proactive assistant with ambient listening, dictation, coding, and command features to simplify both clinical and financial workflows. AI and Product Development Over the past three years, Nabla has invested deeply in product development. The team includes former Meta AI Research engineers, working at the intersection of AI and healthcare. Nabla’s Machine Learning group leverages the latest research to unlock new possibilities for care delivery. Yann LeCun, Chief AI Scientist at Meta and Turing Award recipient, advises Nabla. Engineering at Nabla Nabla’s engineering culture is lean, agile, and technical. Teams specialize in machine learning, native desktop applications, and platform infrastructure, all focused on delivering reliable AI solutions at scale for clinical environments. Role Overview: Full-Stack Engineer (Paris Office) The Full-Stack Engineer will join a cross-functional squad, working alongside product managers, designers, engineers, and domain experts. Squads at Nabla operate with strong ownership, taking products from concept to launch together. Main Responsibilities Build and improve features for Nabla’s web and desktop products. Help design and implement back-end APIs and services.

Join our dynamic team at Altersolutions as an Oracle Finance Cloud ERP Developer. In this role, you will leverage your expertise in Oracle ERP systems to design, implement, and optimize financial solutions tailored to meet our clients' needs. You will collaborate with cross-functional teams to ensure seamless integration and enhance existing functionalities while adhering to best practices in software development.

Join Labelium as a Full Stack Software Engineer Intern in the vibrant city of Paris! In this role, you will have the opportunity to work alongside a talented team of engineers, contributing to exciting projects that shape the future of digital marketing. This internship is perfect for those looking to gain hands-on experience in a dynamic environment.

About INFINIT:Founded in 2023, INFINIT is a dynamic fintech scale-up that is swiftly expanding its presence across Europe and the Americas.Our mission is to transform the future of small and medium-sized enterprises (SMEs) by placing artificial intelligence at the heart of our innovative all-in-one operating system. With banking as a foundational element, we empower small business owners and their teams to efficiently manage and enhance every facet of their operations using AI-driven solutions.By focusing on niche industries, INFINIT offers bespoke, high-value solutions while developing cutting-edge AI products that unlock substantial growth prospects for our clientele. Our global operations are poised for expansion as we aim to redefine the fintech landscape for SMEs around the world.Join us on our journey to revolutionize the SME economy and create a significant impact through innovation Position Overview:We are seeking a passionate and skilled Full Stack Software Engineer to lead our product development initiatives. This role operates on the principle that exceptional engineers do more than just code; they create impactful solutions that meet business needs. Your main task will be to connect business objectives with technical execution, translating broad goals into well-crafted, deployable features.In this role, you will be required to evaluate project requirements, adopt a product-centric approach within the engineering team, and ensure that each line of code delivers real value. The position necessitates strong software engineering skills combined with keen product insight to prioritize and implement high-impact features in a fast-paced environment.