Senior Fullstack Engineer at Aircall | Madrid

Join Aircall, a unicorn and AI-driven customer communications platform, serving over 22,000 companies globally. We are innovating the way businesses communicate by seamlessly integrating voice, SMS, WhatsApp, and AI into a unified workspace.Our growth stems from a straightforward principle: empower teams to work more efficiently. Our AI Voice Agent automates routine calls, AI Assist enhances post-call tasks, and AI Assist Pro provides real-time support, enabling individuals to excel in their roles. This leads to increased revenue, quicker resolutions, and confident team scalability.With headquarters in Paris and a robust North American presence in Seattle, alongside teams in Madrid, London, Berlin, San Francisco, New York City, Sydney, and Mexico City, we have developed a beloved product and a rapidly expanding business, supported by top-tier investors and driven by swift AI advancements across various product lines.At Aircall, you will be part of a dynamic organization. We are ambitious, focused on product excellence, and committed to execution, ensuring visible impacts, quick decisions, and genuine growth.Our Work Culture: We are deeply customer-focused, data-informed, and dedicated to delivering significant outcomes. We prioritize ownership, ongoing learning, and a thoughtful pace. If you thrive in a collaborative, fast-paced setting where trust and impact are key, you will feel right at home here.Role Overview:As a Senior Backend Software Engineer, you will play a crucial role in designing, developing, deploying, and maintaining essential features that enhance customer value through voice integration.You will be expected to advocate for best practices and provide mentorship within your team and across the engineering department.We are driven by quality, excellence, and agility, and you will contribute to elevating these standards.Utilizing a diverse range of backend technology stacks, tailored to meet specific needs and consistently hosted on AWS, we create resilient services that add value to voice integration and seamlessly connect with our clients' critical business tools such as CRM, Helpdesk, E-Commerce, and more.

Join aircall, a leading AI-driven customer communication platform, as we innovate the way businesses interact with their customers. With over 22,000 companies relying on our services, we integrate voice, SMS, WhatsApp, and AI into a unified workspace designed to enhance efficiency and drive revenue.Our vision is simple yet powerful: empower teams to work smarter, not harder. With tools like our AI Voice Agent for automating routine calls and AI Assist Pro for real-time guidance, we ensure that our teams can achieve peak performance and fast resolutions.Headquartered in Paris, with a strong presence in North America and multiple offices including Madrid, London, and New York City, aircall is backed by top-tier investors and is rapidly evolving through AI innovation across various product lines.At aircall, you will be part of a dynamic and ambitious team focused on impactful results. We prioritize ownership, continuous learning, and agile practices. If you thrive in a collaborative and fast-paced environment, you will flourish here.We are seeking a dedicated and enthusiastic Senior Software Engineer to enhance our engineering department and contribute to our innovative projects.In this role, you will oversee the design, development, deployment, and maintenance of essential features that deliver significant value to our customers. You will champion operational excellence and best practices while mentoring your team and the wider engineering community.Your work will focus on elevating quality, excellence, and agility within our delivery processes. You will work primarily with NodeJS and Typescript, ensuring our solutions are effectively hosted on AWS.

Join our dynamic team at Aircall as a Senior Frontend Engineer in our Madrid office! We are searching for a talented engineer who is passionate about building high-quality, scalable web applications. In this role, you will collaborate with cross-functional teams to deliver exceptional user experiences and contribute to our innovative product development efforts.

Join Aircall, a unicorn and AI-driven customer communications platform, trusted by over 22,000 companies globally to enhance revenue, resolve issues swiftly, and expand customer-facing teams. We are revolutionizing customer communications by integrating voice, SMS, WhatsApp, and AI into a cohesive workspace.Our drive stems from a straightforward principle: empower teams to work smarter, not harder. Our AI Voice Agent automates routine calls, AI Assist simplifies post-call tasks, and AI Assist Pro offers real-time guidance, enabling individuals to excel in their roles. The outcome? Increased revenue, expedited resolutions, and teams that scale with assurance.Headquartered in Paris with a robust North American base in Seattle, Aircall also has teams in Madrid, London, Berlin, San Francisco, New York City, Sydney, and Mexico City. We pride ourselves on building a product that delights customers and a rapidly growing business, supported by top-tier investors and propelled by swift AI advancements across various product lines.At Aircall, you will become part of a dynamic company. We are ambitious, product-focused, and execution-oriented, fostering visible impact, rapid decision-making, and authentic growth.Our Work Culture at Aircall: We prioritize customer satisfaction, leverage data, and strive for meaningful outcomes. We cherish ownership, ongoing learning, and thoughtful speed. If you thrive in a collaborative, fast-paced atmosphere where trust and impact are paramount, you'll feel right at home.We are in search of an enthusiastic and dedicated Staff Engineer to join our expanding engineering team and serve as a technical leader across various engineering groups.In this role as a Staff Engineer, you will drive influence across teams and domains, lead the delivery of solutions on cross-functional and strategic projects, and act as a technical leader within the engineering organization. You will uphold quality standards and promote the adoption of best practices in architecture, security, and DevOps.Quality, excellence, and agility are the cornerstones of our delivery processes, and you will help elevate these standards. Proficient in NodeJS and Typescript back-end stacks, tailored to each requirement, you will always ensure optimal hosting solutions.

Join Aircall, a leading unicorn in the customer communications sector, revolutionizing how over 22,000 companies engage with their customers globally. Our innovative AI-powered platform integrates voice, SMS, WhatsApp, and AI into a single, compelling workspace, designed to drive revenue, enhance issue resolution, and empower customer-facing teams.Our success is rooted in a clear vision: enable teams to work smarter, not harder. Our AI Voice Agent automates routine calls, AI Assist simplifies post-call tasks, and AI Assist Pro provides real-time insights, allowing individuals to perform at their peak. This leads to increased revenue, quicker resolutions, and scalable teams that operate with confidence.Headquartered in Paris, with a robust North American base in Seattle, Aircall operates across dynamic cities including Madrid, London, Berlin, San Francisco, New York City, Sydney, and Mexico City. Our product is beloved by customers, and we are rapidly scaling, supported by top-tier investors and continuous AI enhancements across diverse product lines.At Aircall, you will be part of an evolving company that is ambitious, product-oriented, and execution-driven, where your efforts yield visible impact, swift decision-making, and genuine growth.Our Work Culture: We are deeply customer-focused, data-centric, and committed to achieving significant results. We encourage ownership, ongoing learning, and thoughtful pace. If you excel in a cooperative, fast-paced environment where trust and influence are paramount, you will thrive with us.We are seeking a motivated and passionate Senior AI Software Engineer to enhance our expanding engineering division and contribute to our engineering teams.As a Senior AI Software Engineer, your role will involve the design, development, deployment, and management of AI-driven features that provide substantial value to our customers. Your daily responsibilities will encompass maintaining operational excellence, leveraging metrics and observability, sharing best practices, and mentoring team members across the Engineering department.Quality, excellence, and agility are the bedrock of our delivery processes, and you will be a key player in enhancing these standards. Our development is based on NodeJS and Typescript back-end stacks, tailored to meet specific requirements and always hosted on AWS, creating resilient services that integrate seamlessly with our customers' critical business tools (CRM, Helpdesk, E-Commerce, etc.).

Join Aircall as a Senior Data Engineer specializing in Analytics to drive our data initiatives and support our decision-making processes. You will collaborate closely with cross-functional teams to harness data and deliver actionable insights that will improve our product and customer experience.

Join aircall, a leading unicorn in the customer communications space, revolutionizing how businesses engage with their customers through an AI-powered platform. With over 22,000 global clients, we merge voice, SMS, WhatsApp, and AI into a unified workspace that enhances team efficiency and customer satisfaction.Our mission is simple: empower teams to achieve more by working smarter. Our innovative AI Voice Agent automates routine calls, while AI Assist streamlines post-call tasks, and AI Assist Pro provides real-time insights to optimize performance. This results in increased revenue, quicker issue resolution, and scalable teams.Headquartered in Paris, with a robust presence in North America through our Seattle office, we also have teams in Madrid, London, Berlin, San Francisco, New York City, Sydney, and Mexico City. Our product is beloved by customers, and our rapid growth is supported by top-tier investors and cutting-edge AI advancements across our offerings.Our Work Culture: At aircall, we prioritize customer focus, data-driven decision-making, and significant outcomes. We cherish ownership, continuous learning, and a sense of urgency. If you thrive in a collaborative and fast-paced environment where trust and impact are valued, you will fit right in.As a Software Engineer, you will play a pivotal role in designing, developing, deploying, and maintaining critical business features that enhance customer value. Your day-to-day will involve ensuring operational excellence, utilizing metrics, and adhering to best practices.Driven by quality, excellence, and agility, you will help elevate our delivery processes. Leveraging NodeJS and Typescript within our AWS-hosted environment, you will create resilient services that seamlessly integrate with essential customer tools such as CRM, Helpdesk, and E-Commerce platforms.

Join Aircall, a unicorn and AI-driven customer communications platform that empowers over 22,000 companies globally to optimize revenue, enhance issue resolution speed, and scale their customer-facing teams. We are transforming customer communications by integrating voice, SMS, WhatsApp, and AI into one cohesive workspace.Our growth is fueled by a fundamental principle: enabling teams to work smarter, not harder. With our AI Voice Agent automating routine calls, AI Assist simplifying post-call tasks, and AI Assist Pro offering real-time support, our teams can focus on delivering exceptional results. This translates to increased revenue, quicker resolutions, and teams growing with assurance.Headquartered in Paris with a robust North American presence in Seattle, Aircall operates across major cities including Madrid, London, Berlin, San Francisco, New York City, Sydney, and Mexico City. Our innovative product is beloved by customers, and we are rapidly scaling with the support of world-class investors, driven by cutting-edge AI advancements across our product suite.At Aircall, you will be part of a dynamic organization. We are ambitious, product-focused, and execution-oriented, characterized by impactful contributions, swift decision-making, and genuine growth.Our Working Philosophy: We prioritize customer satisfaction, leverage data insights, and are committed to achieving significant outcomes. We value responsibility, continuous learning, and thoughtful agility. If you thrive in a collaborative and fast-paced environment where trust and impact are paramount, you will find your place with us.About the Role: We are actively seeking a Database Engineer with a platform-oriented mindset to reinforce our Infrastructure department. In this position, you will not merely handle support tickets or adjust SQL queries; rather, you will act as a force multiplier and an facilitator, with a keen focus on reliability and scalability. Your mission will involve transforming your extensive database knowledge into tools and platforms that simplify database management and observability for our product engineers. You will create

Join Aircall as a Senior Backend/Platform Engineer, where you will play a crucial role in enhancing our platform's infrastructure and backend systems. You will collaborate with cross-functional teams to design and implement scalable solutions that ensure seamless communication for our users. If you are passionate about crafting high-performance systems and thrive in a dynamic environment, we would love to hear from you!

Join Aircall as a Senior Software Engineer specializing in Applied AI for Corporate Systems. In this pivotal role, you will leverage cutting-edge AI technologies to enhance our corporate systems, driving innovation and efficiency across the organization. You will collaborate with cross-functional teams to design, develop, and implement robust software solutions that meet the dynamic needs of our business.

Join our dynamic team at Aircall as an Infrastructure Engineer in our Madrid office! We are seeking a talented engineer to help us build and maintain our infrastructure, ensuring optimal performance and reliability. As part of our innovative environment, you will work closely with other engineers to design solutions that scale effectively and meet our growing needs.

Join our dynamic team at Aircall as a VoIP Engineer, where you will play a pivotal role in enhancing our voice communication services. In this position, you will be responsible for designing, implementing, and maintaining VoIP systems that ensure seamless communication for our clients. You will collaborate closely with cross-functional teams to optimize performance and provide exceptional support. If you are passionate about voice technologies and eager to make a significant impact, we want to hear from you!

Join Aircall, a groundbreaking AI-driven customer communications platform utilized by over 22,000 companies globally, aimed at enhancing revenue, expediting issue resolution, and empowering customer-facing teams. We are revolutionizing customer interactions by seamlessly integrating voice, SMS, WhatsApp, and AI into a unified workspace.Our success is rooted in a straightforward principle: to enable teams to operate more intelligently, not harder. With tools like Aircall’s AI Voice Agent for automating routine calls, AI Assist for streamlining post-call tasks, and AI Assist Pro for real-time support, we empower our teams to excel. This leads to increased revenue, quicker resolutions, and scalable teams operating with confidence.Headquartered in Paris, with a robust North American presence in Seattle, and teams across cities including Madrid, London, Berlin, San Francisco, New York City, Sydney, and Mexico City, Aircall boasts a product that delights customers and a rapidly growing business, supported by top-tier investors and driven by swift AI innovations across various product lines.At Aircall, you will become part of a dynamic organization. We are driven by ambition, focused on product excellence, and dedicated to execution, offering visible impact, rapid decision-making, and real growth opportunities.Our Work Culture at Aircall: We prioritize our customers, leverage data, and concentrate on delivering significant outcomes. We cherish ownership, continuous learning, and a measured pace of work. If you thrive in a collaborative, fast-paced environment where trust and impact are paramount, you will feel right at home.Role Overview: As a Scale Customer Engineer (SCE), you will be crucial in ensuring that Aircall’s SMB/Core and long-tail customers have a successful onboarding experience, quickly adopt our products, and maintain healthy engagement through both proactive and reactive outreach. Your responsibilities will include leading webinar-based onboarding sessions, conducting proactive telemetry outreach, and providing rapid consulting for Account Managers within your designated customer pool. This high-impact, customer-facing role is ideal for individuals who are resourceful, articulate communicators, strong presenters, and adept at guiding customers through large-scale activation.

Location: Madrid Office About Aircall Aircall builds an AI-driven customer communications platform used by over 22,000 businesses worldwide. Our product brings together voice, SMS, WhatsApp, and AI features in a single workspace, helping teams boost revenue, resolve issues faster, and scale their operations efficiently. Headquartered in Paris, Aircall has a strong global footprint with offices in Seattle, Madrid, London, Berlin, San Francisco, New York City, Sydney, and Mexico City. Our company is growing quickly, supported by leading investors and advances in AI across our product lines. Our Culture We focus on customer satisfaction, data-driven decisions, and meaningful results. Team members are encouraged to take ownership, keep learning, and act quickly but thoughtfully. Collaboration, trust, and impact shape our daily work. About the New Product Unit Aircall is launching a New Product Unit dedicated to advancing autonomous sales. The team is building an AI Orchestration Layer that records and understands customer interactions across calls, video, email, and WhatsApp. This system will automate sales workflows such as CRM updates, follow-ups, task creation, and coaching insights. Our long-term vision is a self-optimizing Sales OS powered by specialized AI agents working together to improve revenue processes. Role Overview: Senior Backend Software Engineer (Python) This position calls for an experienced backend engineer with strong Python skills, ready to work beyond traditional backend boundaries. The role suits someone who values both clean architecture and practical progress, and who can balance high-quality work with the need for speed in a startup setting. What You Will Do Tackle complex technical challenges, including distributed systems, AI orchestration, architecture, performance, and scalability Contribute to the design and implementation of backend systems for the AI Orchestration Layer Work closely with product and engineering teams to deliver new features Iterate quickly, shipping solutions and learning from feedback Who Will Thrive Engineers who enjoy solving difficult problems and making architectural decisions Those who can dive deep into technical details while keeping an eye on rapid delivery People who take pride in their work and appreciate the pace of a growing company

Role Overview airapps is hiring a Backend QA Engineer based in Madrid. This position focuses on quality assurance for backend systems, helping to keep applications reliable and up to standard. What You Will Do Support QA processes for backend applications Work closely with team members to identify and resolve issues Help ensure applications perform as intended and meet quality expectations Who We’re Looking For Detail-oriented approach to testing and problem-solving Comfortable working within a collaborative team Motivated to deliver solid, dependable software Location This role is based in Madrid.

Managing expenses shouldn’t be a headache. At Pleo, we’re revolutionizing the way businesses handle spend management by creating solutions that simplify financial processes for both finance teams and employees. Our goal is to empower organizations to 'go beyond' traditional methods.Since our inception 10 years ago, we’ve embraced the philosophy of ‘Pleo’, meaning ‘more than you’d expect’, which has been pivotal to our success.We are currently at a significant juncture in our growth journey; every decision we make affects our more than 40,000 customers, our business, and our collective achievements. We are looking for individuals who take pride in identifying customer needs, transforming complex challenges into straightforward solutions, and respectfully challenging the status quo. With our ambitious goals ahead, we are a dynamic and diverse team of over 850 individuals from more than 100 nationalities, dedicated to shaping the future of business spending.About the RoleWe are seeking a skilled Backend Engineer to join our innovative team at Pleo. In this position, you will play a crucial role in building and scaling our backend systems, engaging in exciting projects as we expand our product and service offerings. If you are passionate about solving intricate technical challenges and thrive in a culture that values transparency, collaboration, and innovation, we invite you to apply.What You’ll Be DoingAs a Backend Engineer, your responsibilities will include:Designing, building, and maintaining scalable microservices primarily using Kotlin.Collaborating with cross-functional teams to develop innovative solutions across various domains such as Platform, Services, and SMB.Analyzing system performance and implementing optimizations to ensure high reliability and scalability.Participating in code reviews and post-mortems while mentoring fellow engineers.Proactively addressing technical debt and guiding the team through challenges and migrations.What You BringThis role is ideal for you if you possess:Experience in server-side languages, particularly Kotlin, along with expertise in distributed systems, microservices, and cloud environments (e.g., AWS, Kubernetes).Proficiency with relational databases such as PostgreSQL and familiarity with testing frameworks (e.g., JUnit, Testcontainers).

As a Senior Backend/Platform Engineer at causaprima, you will be responsible for the foundational platform utilized by our agents. Your expertise will enhance our event-driven architecture, streamline data pipelines, integrate with customer accounting systems, and ensure that our infrastructure is reliable, auditable, and efficient.Key ResponsibilitiesEvent Store Management — Design and maintain an append-only PostgreSQL database featuring tamper-evident hash chaining, real-time event distribution, agent replay, recovery capabilities, and schema versioning.Cryptographic Signature Infrastructure — Establish key management and signature verification systems for all agent events while implementing approval chains for external actions.Workflow Constraint Engine — Develop a gateway to verify authorization for any external actions including emails, payments, or API calls.PII Vault & GDPR Compliance — Create isolated, encrypted storage solutions for personal data, ensuring compliance with the right to erasure and data residency requirements.Multi-Tenancy Management — Implement row-level security and tenant isolation across all data stores, including tenant-scoped LLM API keys.Authorization Framework (Cerbos) — Utilize attribute-based access control for both agents and humans, ensuring deterministic policy evaluation where LLMs do not make authorization decisions.MCP Security Layer — Develop authentication, capability-based scoping per partner, and rate limiting for the Model Context Protocol endpoint.Database Architecture — Focus on PostgreSQL schema design, indexing strategies, performance tuning, and read replica topology.

About the Role airapps is looking for a Backend Engineer in Madrid to help shape the systems behind our platforms. This role centers on building and improving backend architecture that supports our applications. What You Will Do Design, implement, and maintain scalable backend systems Work closely with teams across the company to deliver new features and solutions Contribute to the ongoing improvement of our backend platforms Location This position is based in Madrid.

Join the Digital Revolution!At Aleph, we are not just participating in the digital advertising landscape; we are actively shaping its future. As representatives of the world’s leading platforms, including TikTok, Amazon, Google, and nearly 55 others, we operate across 130+ markets worldwide.Our mission is to empower advertisers and brands to harness the full potential of these platforms' advertising capabilities. By nurturing long-term partnerships, we create limitless opportunities for businesses to advertise effectively at both local and global levels.With a presence spanning multiple continents, Aleph offers you the opportunity to join a rapidly growing and innovative team where your contributions will have a direct impact. If you are ambitious, forward-thinking, and eager to thrive in a dynamic global environment, Aleph is the ideal place to advance your career.We are looking for a talented Senior Backend Developer who excels in designing, building, and maintaining high-throughput, event-driven systems. In this pivotal role, you will be instrumental in shaping our core platform, making vital architectural decisions, and mentoring fellow engineers. Your responsibilities will include ensuring reliable communication between our asynchronous services, facilitating seamless data flows, and enabling our entire ecosystem to scale according to demand. If you are passionate about message queues, stream processing, and the intricacies of distributed systems, we invite you to apply for this exciting opportunity.