Senior Software Engineer at The Flex | Paris

Join our innovative team that is transforming the future of global living.At The Flex, we envision a world where renting a home is instant, intelligent, and seamless—much like booking a ride. Our mission is ambitious: to empower anyone to live anywhere, anytime, without hassle.Driven by Base360.ai, our unique automation engine, we are crafting the operating system for modern renting—integrating property data, streamlining operations, and facilitating smooth stays across continents.If you are passionate about complex systems, automation, and developing software that has real-world applications, this position offers you the opportunity to take ownership and make a significant impact. What You'll CreateAs a Senior Software Engineer, you will design, develop, and scale essential components of The Flex platform—from core services and APIs to automation workflows and real-time systems.You will work with considerable autonomy, managing problems from start to finish and directly influencing architectural decisions while remaining deeply engaged with production code.This role is for engineers who prioritize impact over meetings and take pride in constructing systems that are reliable, elegant, and scalable. Your ObjectivesDevelop Core SystemsCreate and maintain scalable services that enhance bookings, payments, availability, pricing, and guest experiences.Design Robust APIsEstablish clean, well-structured APIs that connect Base360.ai with internal tools and external partners.Automate OperationsConstruct event-driven workflows that eradicate manual tasks and unlock operational efficiencies.Deploy with AssuranceImplement and manage cloud-native infrastructure on AWS with an emphasis on reliability, security, and performance.Tackle Meaningful ChallengesEngage in real-time booking synchronization, pricing intelligence, keyless access systems, AI-driven alerts, and live operational dashboards.Collaborate for SuccessPartner closely with product, data, and operations teams to transform complex requirements into straightforward, effective systems. Ideal Candidate ProfileExtensive experience in building production systems with Node.js, React, and AWS.Solid understanding of software design principles and best practices.Proficient with CI/CD practices and tools.Strong communication skills and a collaborative mindset.

Become a pivotal member of a visionary team that is reshaping global living standards.At The Flex, our mission is to transform the rental experience, making it instantaneous, intelligent, and seamless—much like booking a ride.Our bold ambition? To empower individuals to live anywhere, at any time, without the usual hassles.Utilizing our advanced automation engine, Base360.ai, we are crafting a revolutionary operating system for modern renting—integrating property data, streamlining operations, and facilitating effortless stays across the globe.If you are passionate about developing products from start to finish, have a keen eye for user experience, and thrive on managing tangible systems that impact real users, this role is tailored for you. What You'll CreateAs a Senior Product Engineer, you will navigate the intersection of product, engineering, and operations.You will take ownership of features from conception to deployment—crafting the product, designing the architecture, coding, and implementing enhancements that significantly affect guests, operators, and partners.This position is ideal for engineers who prioritize product development over ticket resolution and are deeply invested in usability, performance, and tangible results. Your Key ResponsibilitiesOwn Product Features End-to-EndDesign, create, and enhance core product experiences across both web applications and APIs.Build for UsersConvert genuine operational and user challenges into straightforward, user-friendly product solutions.Ship Fast, Learn FasterRelease frequently, collect feedback, and continuously iterate.Design Scalable SystemsDevelop clear, maintainable architectures that grow alongside the platform.Automate the ExperienceLeverage automation and smart workflows to eliminate friction for both guests and operators.Collaborate CloselyPartner closely with product, design, data, and operations teams to transform ideas into impactful solutions. Ideal Candidate ProfileProven experience in developing user-facing products as a senior engineer.Proficient in working across frontend, backend, and APIs.Familiarity with modern web technologies (React, Node.js, cloud-native platforms).A strong product-oriented mindset—focused on understanding why a feature is developed, not just how.

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.

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.

Become part of a visionary team that is transforming the future of global living from the ground up.At The Flex, we envision a world where renting a home is instant, smart, and effortless — as seamless as hailing a ride. Our bold ambition is to empower anyone to live anywhere, anytime, without any friction.Leveraging our proprietary automation engine, Base360.ai, we are constructing the operating system for modern rental experiences — linking property data, orchestrating operations, and facilitating seamless stays across the globe.This is not just another job where you merely handle tasks; this is an exceptional opportunity to establish the technical foundation of a groundbreaking company and shape the operational framework of a global platform at scale. What You’ll BuildAs a Founding Engineer, you will contribute to the design, construction, and scaling of the core technology that underpins The Flex, starting from scratch.Your responsibilities will span across product, engineering, and operations, where you will take ownership of systems from end-to-end: web applications, APIs, automation pipelines, integrations, and cloud infrastructure.You will make impactful architectural decisions early on — decisions that will influence the company for years to come — while rapidly converting ideas into production systems utilized in the real world.If you thrive in an environment of ambiguity, ownership, and building tangible solutions, this role is tailor-made for you. Your MissionBuild from Zero to OneCreate and implement the foundational architecture for bookings, payments, availability, and guest experience.Own the StackDevelop across frontend, backend, APIs, and cloud infrastructure — selecting tools and patterns that will scale effectively.Automate the BusinessTransform manual processes into event-driven workflows and intelligent automation from day one.Integrate the EcosystemEstablish deep integrations with platforms like Airbnb, Stripe, Hostaway, and Twilio.Ship RelentlesslyDeploy, monitor, and iterate on production systems with speed, reliability, and practicality.Solve Real-World ProblemsAddress challenges such as real-time booking synchronization, pricing intelligence, keyless access logic, AI-driven alerts, and operational dashboards.Set the Technical DNADefine engineering standards, best practices, and foster a culture of quality, ownership, and execution.

At Swile, we are committed to enhancing professional experiences through innovative product solutions that alleviate daily challenges and elevate employee satisfaction. Our cutting-edge offerings in Fintech, Travel, HR, and Employee Benefits serve over 5.5 million users across 85,000 companies in France and Brazil, making a significant impact on the workplace.As a Senior Software Engineer, you will play a pivotal role in problem-solving, blending creativity with technical expertise. Your focus will be on delivering high-quality solutions swiftly and effectively, addressing both business and engineering challenges with innovative strategies rather than being restricted to specific technologies.

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.

We are seeking a talented and experienced Senior Software Engineer to join our dynamic team at believe. In this role, you will be responsible for designing, developing, and maintaining high-quality software solutions that meet the needs of our users. You will collaborate closely with cross-functional teams to understand requirements and implement innovative solutions that drive our mission forward.The ideal candidate is passionate about technology, has a strong foundation in software engineering principles, and is eager to tackle complex challenges. If you thrive in a fast-paced environment and are looking to make a significant impact, we want to hear from you!

Join our dynamic team at vusiongroupsa as a Senior Software Engineer, where you'll have the opportunity to contribute to innovative projects that shape the future of technology. We are looking for a skilled professional who can bring their expertise in software development, work collaboratively with our R&D department, and drive excellence in our engineering practices.

Join Aircall, a groundbreaking AI-driven customer communications platform utilized by over 22,000 businesses globally, enhancing revenue, expediting issue resolution, and empowering customer-facing teams. We are transforming customer interactions by seamlessly integrating voice, SMS, WhatsApp, and AI into a cohesive workspace.Our growth is fueled by a core philosophy: enable teams to work smarter, not harder. With innovations like Aircall's AI Voice Agent automating routine calls, AI Assist simplifying post-call tasks, and AI Assist Pro providing real-time support, our solutions enhance productivity leading to increased revenue and swift resolutions.Headquartered in Paris, we also boast a robust North American presence in Seattle, along with teams across Madrid, London, Berlin, San Francisco, New York City, Sydney, and Mexico City. Our product has garnered a loyal customer base, and we are rapidly scaling with the backing of premier investors and a commitment to continuous AI innovation across our offerings.At Aircall, you will be part of a dynamic organization. We are ambitious, product-oriented, and execution-driven, emphasizing impactful work, swift decision-making, and genuine growth.Our Work Culture at Aircall: We are dedicated to our customers, driven by data, and focused on delivering impactful results. We value ownership, continuous learning, and thoughtful speed. If you excel in a collaborative, fast-paced environment where trust and impact are paramount, you'll thrive here.We are seeking a passionate and engaged Senior Software Engineer to enhance our expanding engineering department and contribute to our teams.As a Senior Software Engineer, you will lead the design, development, deployment, and operation of crucial features that deliver value to our customers. Your responsibilities will include ensuring operational excellence, monitoring key metrics, enhancing observability, promoting best practices, and mentoring team members across the Engineering division.Driven by quality, excellence, and agility, you will play a pivotal role in elevating our delivery processes. Utilizing NodeJS and Typescript within a robust back-end framework on AWS, you will tailor solutions to meet varied requirements.

Believe is a music company focused on supporting artists and labels. The team in Paris is looking for a Senior Software Engineer to help shape new projects and improve the digital platform. Role overview This position involves working with teams from different areas to create software that can grow with the company's needs. The work centers on building and improving products that help the music industry adapt and develop. What you will do Work closely with colleagues from various disciplines to design and develop software solutions Contribute technical expertise to projects that expand and strengthen Believe’s digital ecosystem Requirements Strong background in software development Interest in building products that support artists, labels, and the broader music industry Ability to collaborate effectively within cross-functional teams This role is based in Paris and offers the chance to contribute to projects that influence the future of music.

Paris | Full-time | Fluent in French & English The e-commerce landscape is evolving rapidly, yet independent brands often find it challenging to compete with the logistical efficiency of industry giants like Amazon. At Bigblue, we are dedicated to transforming this reality.Our mission is to empower brands by providing access to top-tier operational capabilities, enabling them to grow swiftly while ensuring an exceptional customer experience.Since our inception in 2018, we have developed an innovative tech-driven logistics platform that currently supports over 500 brands, ranging from rapidly expanding direct-to-consumer enterprises to globally recognized names such as MUJI, Aigle, and Cabaïa. With a talented team of 110+ employees across Paris, Madrid, and London, and our proprietary Warehouse Management System (WMS) Atlas, we are tackling logistics challenges that others shy away from — making fulfillment processes faster, smarter, and more sustainable.Backed by over $20 million in funding and trusted by the next generation of e-commerce innovators, we are experiencing rapid growth — aiming to handle 10 million orders in 2024 and embarking on ambitious enterprise expansion. The future is bright, and we’re searching for the right partners to help us lead the charge.

Join Our Team at KovaleeAt Kovalee, established in 2020, we are on a mission to revolutionize the mobile industry by empowering app developers to reach the pinnacle of their niche, irrespective of their resources. Our cutting-edge technology and deep expertise in user acquisition, app store optimization, product enhancement, and monetization enable developers to concentrate on their passion while we accelerate their app's growth. Our successful applications, such as Bend, PepTalk, and ParrotPal, showcase our commitment to excellence and our ability to drive results.Recognized as one of the fastest-growing startups of 2024 by Sifted, we are a diverse team of over 20 professionals from more than 15 nationalities, unified by a common goal: to redefine the mobile app landscape.We are seeking a Senior Software Engineer to become a crucial part of our team, responsible for creating and sustaining the foundation of our publishing platform. In this role, you will collaborate closely with operations to address real-world business challenges while helping us innovate rapidly and ambitiously. You will report directly to the CTO and work alongside another talented software engineer.

Join our innovative team at Vusion Group as a Senior Software Engineer. In this crucial role, you will be responsible for developing high-quality software solutions, collaborating with cross-functional teams, and driving technical excellence within our R&D department.Your expertise in software development will be key to delivering robust applications and enhancing existing systems. If you are passionate about technology and looking to make a significant impact in a dynamic environment, we encourage you to apply.

Alice & Bob is pioneering the development of the world's first universal, fault-tolerant quantum computer, aimed at tackling some of the most complex challenges facing humanity.Our vision revolves around the innovative Schrödinger cat qubit—a groundbreaking superconducting qubit capable of autonomous quantum error correction, setting it apart from existing superconducting technologies.In the race against industry giants like Google and IBM, we are rapidly expanding, having secured €100 million in funding in 2025 to further advance our unique quantum technology.With a diverse team of over 100 professionals, including physicists, PhD researchers, engineers, and business experts, we are united in our mission to transform the future of computing. Are you ready to be a quantum trailblazer? Join us in our quest to redefine what’s possible!About the Role:The Performance Optimization Team combines the expertise of physicists and machine learning engineers to enhance the quality, speed, and reliability of the quantum chip lifecycle, from design to effective error correction.As a Senior Software Engineer at Alice & Bob, you will act as the architectural anchor for our team, developing the robust software ecosystem essential for scaling quantum innovations from initial concepts to mission-critical production systems.Your contributions will significantly impact the organization; you will elevate engineering standards by creating scalable frameworks, implementing strict best practices, and acting as the primary connection between our research-focused initiatives and the wider software engineering team. In this role, you are not just coding—you are building the foundational systems that will shape the future of fault-tolerant quantum computing.

Alice & Bob is pioneering the development of the world's first universal, fault-tolerant quantum computer to tackle the most challenging problems that humanity faces.Our vision revolves around creating a revolutionary superconducting qubit known as the Schrödinger cat qubit, which stands out in the realm of superconducting platforms by its remarkable capacity to autonomously implement quantum error correction!As a leader in the quantum race, we are in direct competition with industry giants like Google and IBM, and our growth trajectory is accelerating, thanks to securing €100 million in funding in 2025 for advancing our groundbreaking technology.Currently, we boast a diverse team of over 100 professionals including physicists, PhD candidates, engineers, and seasoned business experts, all united in our ambitious mission to redefine the future of quantum computing.About the Team:The Framework Team serves as a vital resource, collaborating across the organization with researchers and technicians, and is fundamentally woven into our operational workflows. As a Senior Software Engineer within this team, you will be instrumental in designing, developing, and maintaining top-tier software solutions. Your contributions will enhance our core products and foster innovation as you help build our proprietary software that governs hardware and the experiments we conduct. You will also take on a technical leadership role, mentoring junior engineers and influencing architectural decisions.About the Role:You will lead the definition of our service and platform architecture designed to enable agility, evolution, and scalability of our quantum computing stack. Your primary objective is to create a cohesive, maintainable, and future-proof platform that underpins experimental workflows, automation, logical systems, and ultimately facilitates the delivery of a QPU-as-a-product for high-performance computing or cloud users.Your role will be pivotal in bridging scientific R&D, data engineering, and production-grade platform design, allowing researchers and physicists to iterate swiftly without sacrificing reliability.

Join Aircall, a groundbreaking unicorn in the realm of AI-driven customer communication platforms, utilized by over 22,000 companies globally. Our mission is to transform customer interactions by integrating voice, SMS, WhatsApp, and AI into a singular, efficient workspace.Our progress stems from a core belief: empower teams to operate smarter, not harder. With innovations like Aircall’s AI Voice Agent automating routine calls, AI Assist optimizing post-call processes, and AI Assist Pro providing real-time support, we enhance productivity, drive revenue, and enable teams to scale confidently.Headquartered in Paris, our European hub, we also boast a robust North American presence in Seattle, complemented by teams in Madrid, London, Berlin, San Francisco, New York City, Sydney, and Mexico City. Our product is beloved by customers, our business is rapidly expanding, and we are backed by leading investors, driving swift AI advancements across various product lines.Our Work Culture: We prioritize customer satisfaction, leverage data-driven insights, and aim for impactful results. We value ownership, continuous learning, and deliberate speed. If you thrive in a collaborative, dynamic environment where trust and impact are paramount, you will fit right in.We are seeking a dedicated and enthusiastic Senior Software Engineer to enhance our Workspace team, with a primary focus on Frontend Architecture.In this role, you will be pivotal in transforming Aircall's frontend architecture into a robust platform. Our existing monorepo contains approximately 40 packages and various applications, and as we expand, it is crucial to facilitate parallel contributions from diverse feature teams without generating bottlenecks or architectural conflicts. Your mission is to design a seamless, secure, and high-performing architecture that fosters collaboration.You will serve as a catalyst for the entire engineering organization, establishing the standards for how frontend code is authored, shared, and deployed at Aircall.

About UsZefir stands at the forefront of innovation as Europe's premier AI-driven Real Estate Marketplace. Our mission is to revolutionize the home buying and selling process, enabling transactions at unprecedented speeds—twice as fast as conventional methods. In just two years, we have proudly surpassed €1 billion in Gross Merchandise Volume (GMV).With the backing of over €50 million from prestigious investors such as Sequoia Capital, we are dedicated to transforming the lives of millions of homeowners across Europe.Engineering TeamOur Engineering Team is pivotal in driving Zefir's vision forward. Having expanded from 9 to over 30 engineers in a short span, we don't just write code; we tackle significant challenges that impact our customers' lives.From concept to launch and ongoing optimization, our engineers take complete ownership of their projects, ensuring that every feature achieves its intended impact. We utilize LLM-based development workflows and best practices to automate repetitive tasks, keeping our codebase efficient, scalable, and optimized for speed.Your RoleDesign, develop, and deploy high-performance APIs with Node.js (TypeScript), Nest.js, and GraphQL.Create engaging frontend applications using React.js and Next.js, ensuring exceptional user experiences.Collaborate effectively with Product Managers and cross-functional teams (Operations, Growth, Brand) to prioritize features and meet key objectives.Manage the complete lifecycle of features from ideation and design through to implementation, deployment, and performance evaluation.Write clean, maintainable code that is well-tested, ensuring fast deployments and continuous enhancements.Conduct comprehensive end-to-end (E2E) tests to ensure reliability and streamline code review processes.Play a proactive role in shaping the strategic direction of our web applications and infrastructure.Implement AI-driven functionalities using LLM-based libraries and technologies such as Pinecone and Langchain.

Join Konvu as a Senior Software EngineerAt Konvu, we are dedicated to transforming the landscape of security management, making it seamless and efficient in an increasingly automated world.With the rise of AI-driven code generation and deployment, traditional security methods are becoming obsolete. Our innovative AI agents function like seasoned security engineers, adeptly filtering out noise, validating potential vulnerabilities with substantial evidence, and empowering teams to prioritize what truly matters.Our technology integrates effortlessly into existing workflows without necessitating major overhauls or new systems, delivering actionable insights directly where teams operate. This approach significantly reduces false positives and highlights genuine vulnerabilities confidently.Founded by pioneering members of Sqreen (YC W18, acquired by Datadog), our team possesses deep technical expertise, translating it into tools that developers and security professionals find indispensable.Having secured $5M in seed funding, we are supported by leading VCs from Europe and the US, alongside industry veterans from Datadog, GitHub, Docker, Cloudflare, Sumo Logic, and Vanta.We invite an expert-level Software Engineer to join our Paris team and contribute significantly to our mission.

Join aircall, a pioneering unicorn in the realm of AI-driven customer communication platforms, utilized by over 22,000 companies globally to enhance revenue, expedite issue resolution, and effectively scale customer-facing teams. We are transforming the landscape of customer communications by integrating voice, SMS, WhatsApp, and AI into a unified workspace.Our growth is fueled by a straightforward principle: empower teams to work smarter, not harder. Our innovative AI Voice Agent automates routine calls, AI Assist optimizes post-call tasks, and AI Assist Pro provides real-time guidance, enabling individuals to perform at their best. This results in increased revenue, quicker resolutions, and teams that expand confidently.Based in Paris, our European headquarters, we have a robust North American presence in Seattle and teams across Madrid, London, Berlin, San Francisco, New York City, Sydney, and Mexico City. Our product is beloved by customers, and our business is rapidly expanding, supported by top-tier investors and driven by swift AI innovations across various product lines.Our Work Culture: At aircall, we prioritize customer satisfaction, data-driven decision-making, and delivering significant outcomes. We value ownership, continuous learning, and thoughtful speed. If you excel in a collaborative, dynamic setting where trust and impact are paramount, you will thrive here.We are in search of a dedicated and enthusiastic Senior AI Software Engineer to join our expanding engineering team.In this role, you will oversee the design, development, deployment, and operation of AI-driven features that enhance customer value. Your daily responsibilities will encompass operational excellence, metrics, observability, best practices, and mentoring within your team and across the engineering department.We are committed to quality, excellence, and agility in our delivery processes, and you will play a key role in elevating these standards. Utilizing NodeJS and TypeScript back-end technologies, suitable for each requirement, and always hosted on AWS, we create valuable and resilient services built on voice technology that seamlessly integrate with our customers' essential business tools (CRM, Helpdesk, E-Commerce, etc.).