Senior Fullstack Engineer

FREENOW

Location: Come and join us in Barcelona! We are looking for a talented and motivated Senior Backend Engineer (m/f/d) for our new Driver Onboarding team. As part of a highly skilled, cross-functional team comprising Fullstack Engineers, Backend Engineers, a Product Manager, a Product Designer, a Data Analyst, and a technical Engineering Manager, you will help shape the future of mobility with FREENOW and assist our drivers in their daily work. Our team is the cornerstone of the driver experience, with a core focus on streamlining the driver registration flow and ensuring the integrity of our platform through advanced document validation processes. Our mission is to provide a fast, frictionless, and secure onboarding journey for every new driver. We achieve this by: * Designing and implementing the entire driver registration and onboarding journey, making it simple, intuitive, and fast. * Developing and maintaining robust, automated document validation systems, powered by LLMs and ML models, to ensure compliance and quick approval for drivers. * Collaborating closely with Operations and other engineering teams to constantly optimize process automation within the document lifecycle. * Providing self-service tools that empower drivers to efficiently manage their documentation and account details. * Integrating key insights into internal systems, fostering collaboration across teams to improve the overall driver experience. As a critical part of our company, this team's work directly impacts thousands of drivers and, ultimately, the experiences of millions of customers. Your contributions in this role will have a tangible and far-reaching effect on the lives of many. As an engineer on our team, you will tackle the exciting challenges of building a best-in-class driver onboarding platform. This includes designing and building innovative, high-scale solutions for document validation and workflow automation, directly enhancing the start-to-finish experience for our drivers and ensuring the quality and compliance of our fleet. You'll be involved in every stage of product development, from ideation to implementation, ensuring a seamless and impactful experience. We also value a mindset that challenges the status quo—constantly exploring new technologies and approaches to improve our products and maintain a state-of-the-art codebase. Beyond technical excellence, your contributions will help foster a collaborative and inspiring team culture, making our workplace an enjoyable and fulfilling environment. ---------------------------------------------------------------------------------------------------------------------------------- YOUR DAILY ADVENTURES WILL INCLUDE: * Own the Feature, Own the Code – feel responsible for what you create. It all starts with bringing in your feature ideas, goes over development, testing and ends in deploying your code and monitoring it. * Design and develop systems based on product requirements or refactorings. * Maintain and improve the existing systems by finding bottlenecks and performance issues and improving resource usage (DB access, cache, messaging, etc.). * Collaborate with your team members in an Agile environment, contribute to and live our agile ceremonies. * You care about teamwork: Be accountable for all topics above, but work together with the team on them. * Stay on top of the latest technology trends and AI-assisted development tools, and bring best practices to our daily work. Our Techstack: Kotlin | Java | AWS | Docker | Git | Kafka | ElasticSearch & more ---------------------------------------------------------------------------------------------------------------------------------- TO BE SUCCESSFUL IN THIS ROLE: * Passionate about Kotlin or Java. * Experience with the quirks of Spring Boot or similar frameworks, automated tests and CI/CD tools. * Knowledge of microservices architecture. * Comfortable with AI-first development practices, we use tools like Claude and Cursor daily, so experience or strong interest in AI-assisted coding is important. * Familiarity with monitoring tools (i.e., Grafana, Datadog, Kibana etc.). * Keen about principles and practices of scalable web applications, such as RESTful API’s, dealing with transactions, and resiliency. * Familiar with messaging by using Kafka or RabbitMQ. * High level of creativity; there’s all the freedom to think outside the box. * Be communicative, proactive, and always collaborative. * Excellent written and verbal communication skills in English. Nice to have:  * Experience working with AWS or similar cloud service providers. * Experience in Python, particularly for data processing or AI integration tasks. * Experience with document automation validation. * Familiar with Agile methodologies such as Scrum or Kanban. ---------------------------------------------------------------------------------------------------------------------------------- BENEFITS & PERKS IN A NUTSHELL: * Flexible working arrangements * LinkedIn Learning * Sabbatical & special leave policies * WeRoad partnership * Birthday, 24th + 31st December off * Short term EU work policy * Mobility Credit * Health Insurance * Employee assistance program   ---------------------------------------------------------------------------------------------------------------------------------- DIVERSITY, EQUITY & INCLUSION: FREE NOW is an equal opportunity employer and we consider qualified applicants regardless of race, religion, national origin, gender, gender identity, sexual orientation, disability or age. We want you to grow and evolve, bring your true self to work. ABOUT US: Freenow by Lyft empowers smarter mobility decisions, helping people to move freely and cities to thrive. Through our multi-mobility app, we feature broad options for everyone across 9 European markets and over 180 cities. Millions of passengers can access services including taxis, private hire vehicles, carsharing, car rental, e-scooters, e-bikes, e-mopeds, and public transport within a single app.  In July 2025 Freenow was acquired by Lyft, a global mobility platform, which connects riders and drivers for billions of rides across North America and Europe. Together, Freenow and Lyft are creating a more caring and connected world, with transportation for everyone. We are a global, diverse, highly motivated, and collaborative team that strives for excellence and likes to have fun. Ready for your next ride? ---------------------------------------------------------------------------------------------------------------------------------- SEE WHAT OUR AWESOME COLLEAGUES SAY ABOUT US:                 ----------------------------------------------------------------------------------------------------------------------------------

Antai Ventures

Antai Ventures is a Barcelona-based venture studio with presence across Southern Europe and Latam. Since 2012 we have co-founded 35+ companies including Glovo, Wallapop, Piper, PlatanoMelon, and Vitaance. Our ventures have raised more than $1.5B in funding, have generated more than $3B in shareholder value, and currently employ more than 3,000 people. At Antai, we partner up and invest in the best co-founders to build global companies willing to disrupt multi-billion dollar industries. In the last 12 years, we have gained experience in a variety of business models (E-Commerces/DNVBs, B2B SaaS, Marketplaces) operating in a wide range of industries including Edutech, Grocery, Healthtech, Fintech, Insurtech, Proptech, Autotech, among others. We are looking for a Senior Full-Stack Engineer to join the founding team of one of our portfolio companies — a B2B SaaS platform that helps service companies manage the complex, day-to-day operations of their distributed frontline workforce. Think scheduling, real-time coordination, coverage resolution, time tracking, and client communication — all powered by an AI agent that can make phone calls, contact workers, and take autonomous action to keep operations running smoothly. The vision is ambitious: build the operating system for an entire industry — starting with day-to-day operations, then expanding into deeper integrations across finance, HR, and everything else these companies need to run their business. AI isn't a feature we're bolting on — it's embedded from day one as a core capability that fundamentally changes how these companies operate. THE ROLE You’ll be one of the first engineers on a small, high-ownership team building a product from the ground up. This isn’t a role where you’ll be handed tickets — you’ll be researching customer problems, crafting detailed specs, designing solutions, writing code, and shipping features end-to-end. You’ll work directly with the founders and be expected to bring strong judgment about what to build, how to build it, and when to keep things simple. We need someone who is genuinely full-stack: comfortable across backend, database, frontend, mobile (web-based via Capacitor), and cloud infrastructure. You don’t need to be an expert in every layer, but you need the confidence and curiosity to work through problems across the entire stack, learn what’s needed, and find the right solution for the context. 📍 Location: Barcelona, hybrid (some office days) 📝 Employment: Full-time 🎤 Languages: Proficient English required. Spanish not required, but a basic level is a plus. 💰 Compensation: €50–70K + equity WHAT YOU’LL WORK ON * Study customer problems deeply and translate insights into detailed functional and technical specs — then turn those specs into working software. * Design and build core backend systems powering workforce scheduling, real-time coordination, and operational workflows. * Build clean, well-structured APIs and data models that support web, mobile, and internal tools. * Develop the worker-facing mobile experience (web-based, via Capacitor) with a focus on simplicity for low-tech-savviness users. * Contribute to the AI agent’s backend — the infrastructure that lets it resolve coverage incidents, contact workers, and take autonomous actions. * Manage and evolve cloud infrastructure, CI/CD pipelines, and developer tooling. * Improve reliability, observability, and performance across the system. * Build integrations with other business software the industry already uses — accounting, payroll, and other operational tools. * Participate in design reviews and product decisions, bringing engineering perspective to what gets built and how. YOUR FIRST 3–6 MONTHS You’ll ramp up fast. Here’s what that might look like: * Immerse yourself in the domain — studying how service companies actually run their operations day-to-day, reviewing processed customer insights, and building a mental model of the problems we’re solving. * Pick up existing specs, understand the reasoning behind them, and start shipping features from detailed functional and UI specifications. * Start crafting your own specs — studying a problem, collaborating with the team to refine the approach, designing the implementation, and seeing it through to production. * Build and iterate on the worker-facing mobile experience, making it intuitive for frontline workers with minimal tech experience. * Get hands-on with the local-first sync layer (ElectricSQL, TanStack DB) as real usage reveals edge cases and design tradeoffs. * Help shape the AI agent’s capabilities — how it reasons about coverage, contacts workers, and escalates to managers. * Improve the development workflow itself — testing patterns, CI/CD, tooling, and the feedback loop between specs and code. Throughout all of this, you’ll be leveraging AI coding agents heavily — not as an afterthought, but as a core part of how you research, design, plan, implement, and review. WHAT WE’RE LOOKING FOR Strong engineering fundamentals * You’ve designed and operated production systems and understand the tradeoffs between latency, consistency, cost, and complexity. * You write simple, maintainable code and care deeply about good abstractions. You know that simplicity is the ultimate sophistication. * You’re comfortable owning systems end-to-end: from research and spec writing, through design and implementation, to deployment and operations. * You have solid experience with TypeScript, SQL, and modern web frameworks. Our stack is Vue, Nuxt 4, Nuxt UI, PostgreSQL, ZenStack/Prisma, ElectricSQL, TanStack DB, and Capacitor. * You’ve worked with cloud infrastructure (GCP, AWS, or similar) and understand CI/CD, containerization, and production operations. AI-augmented engineering * You use AI coding agents daily and can orchestrate multi-file agentic workflows with tools like Claude Code, Cursor, or similar — not just autocomplete, but steering complex architectural decisions and reviewing AI-generated output for quality and maintainability. * You can effectively amplify yourself using AI across the entire development lifecycle: research, spec writing, design, implementation, code review, and debugging. * You stay current with the AI tooling ecosystem and have opinions about what works and what doesn’t. Product and business sense * You can see the bigger picture. You deeply understand customers and their world, and you balance business goals and constraints in your engineering decisions. * You anticipate problems before they arrive and know when to compromise, be pragmatic, and avoid over-engineering. * You’re a clear communicator who can articulate technical tradeoffs to non-technical teammates and write specs that others can follow. Zero-to-One energy * You thrive in the earliest stages of building — where there's no playbook, priorities shift fast, and the best move is often the scrappy one that gets things done now. * You're comfortable with high intensity and ambiguity. You don't need a perfectly defined scope to start making progress. * You've been through the 0→1 phase before (or you're hungry for it) and you understand that speed of iteration matters more than perfection. NICE SIGNALS * Experience with local-first / offline-first architectures or real-time sync. * Experience building mobile apps with Capacitor or similar web-to-native bridges. * Familiarity with the Vue/Nuxt ecosystem. * Experience in B2B SaaS, workforce management, or field service operations. * You’ve worked in early-stage startups and are comfortable with ambiguity and fast-changing priorities. * Experience integrating LLMs into production systems (function calling, RAG, agentic workflows). HOW WE WORK * Spec-driven development. Features are designed through detailed specs before code is written. Engineering decisions are informed and deliberate, not reactive. * AI-augmented workflow as standard practice. AI coding agents aren’t a novelty here — they’re part of how the team operates daily, across every phase of the development cycle. * Structured async + tight real-time alignment. We use Linear for task-centered work and value deliberate, organized communication. At the same time, we stay tightly in sync through lightweight, real-time collaboration — the natural rhythm of a small team that keeps each other in the loop without meetings and status rituals. * Direct collaboration with founders. No layers of product management between you and the people making product and business decisions. * Small team, high standards. We optimize for learning speed and iteration velocity, not process and ceremony. WHY THIS ROLE * You’ll shape the product and architecture from the earliest stage — the systems you build will exist for years. * You’ll work on a genuinely AI-native product where an autonomous agent is a core differentiator, not a marketing checkbox. * You’ll have real ownership and direct impact on what gets built, how it’s built, and how fast the company moves. * You’ll join a team that takes engineering craft seriously while staying pragmatic about what matters at this stage. * You’ll help define what “great engineering” looks like at a company that’s just getting started.

Wallapop

Wallapop is a Barcelona based scale-up driven by the purpose to empower people to embrace a more conscious and human way of consumption. We believe in a world where collaborative economy is mainstream. This is what drives us. 💫 Wallapop operates in Spain, Italy and Portugal, offering a catalogue of several hundreds of millions of products and services. Powered by technical innovation and continuous improvement, we bring together the scale & trust of classifieds with the marketplace’s convenience & reach. 🌱 Our mission is to enable a connected trade ecosystem, making 2nd-hand the norm through smart use of technology.   THE CHALLENGE 🧩 Are you ready to kickstart your engineering career? We are launching our first cohort of our Full-Stack Graduate Program—an immersive, 21-month rotational journey designed to cultivate adaptable, high-impact T-shaped software engineers.   At Wallapop, we believe in building solid vertical depth in a core technology while fostering a horizontal, working fluency across the rest of our ecosystem. Over the course of 21 months, you will complete three distinct 6-month rotations through our core engineering chapters—shipping real production code used by millions—alongside a 3-month business immersion rotation: * Backend Chapter (6 months): Deep dive into robust, scalable server-side systems using Kotlin & Java (with Spring Boot, Ktor, AWS, and microservices). * Frontend (Web) Chapter (6 months): Build responsive, elegant, and modern web applications using React & Angular. * Mobile Chapter (6 months): Craft exceptional native mobile experiences on either iOS (Swift) or Android (Kotlin/Java) depending on team fit. * Business Immersion (3 months): Step outside of engineering to complete a rotation in non-engineering departments. This will allow you to get to know other parts of the business and gain an understanding of how Wallapop operates as a whole.   You will be supported by a comprehensive, three-tier mentorship model including a dedicated Anchor Engineering Manager for your entire 21-month journey, a rotating Chapter Mentor for daily pair-programming, and a Rotation Team Manager to integrate you into cross-functional agile rituals. We also treat AI-native developer tooling (GitHub Copilot, Claude, etc.) as first-class citizens to help you ramp up and contribute fast! WHAT YOU WILL DO 👇 Build and ship features on systems used by millions of buyers and sellers — real work, not training exercises. * Rotate across engineering chapters over 18 months, gaining hands-on experience in Backend (Kotlin/Java), Frontend/Web (React/Angular), and one mobile platform (iOS or Android). * Rotation in a non-engineering department over 3 months. This will allow you to get to know other parts of the business and gain an understanding of how Wallapop operates as a whole. * Work with senior and mid-level engineers and cross-functional stakeholders who will mentor you, review your code, and push you to grow. * Use AI tooling as a first-class part of your workflow — Copilot, Claude, and similar tools are how we work, not an afterthought. * Participate fully in team life: standups, planning, retros, code reviews. * Own your learning — flag blockers fast, ask questions freely, and teach back what you're learning. WHAT WE’RE LOOKING FOR 🔎 We care more about how you think and learn than about what's on your CV. We're looking for people who are genuinely curious, who want to understand systems rather than just pass tests, and who are motivated by building things that matter. * Fresh graduate — University (e.g., UPC), Grado Superior, or equivalent. This is your first professional engineering role. * Basic coding fluency — you've built things, you can debug, you understand what your code actually does. * Curiosity — you ask why, not just how. * Learning velocity — you pick things up fast and lean into unfamiliar territory. * Openness to breadth — you're not here to be a one-stack specialist. You want to understand the whole picture. * Care — you want to do software well, for the right reasons. * Fluent English — Ability to communicate clearly and effectively with English-only stakeholders across Wallapop. WHAT WE OFFER 🚀 * Permanent contract from day one — you're an engineer at Wallapop, not a trainee on a clock. * 21 months of structured rotation with real ownership at every stage. * A dedicated mentor per chapter + a stable Anchor Engineering Manager across the full program. * AI-native onboarding — you'll be set up with the tooling and context to contribute fast. * A clear path to becoming a fully fledged Full-Stack Engineer at the end of the 21-month rotation. * Competitive graduate salary. * Wallapop's standard benefits package (detailed below!). Do note that all our jobs are 📍 Barcelona based. We follow a hybrid model where flexibility rules. We commit to a minimum of 6 days per month in the office. Each team self-organizes to decide on cadence and in-person/remote rituals. Wallapop is an equal opportunity employer. We celebrate diversity and are committed to creating an inclusive environment for all employees as we want Wallapop to be a place for everyone. Additionally to the opportunity to contribute to an agile product set up and work together towards achieving our meaningful mission, we offer the following 🍭 Perks & Benefits: * Generous individual learning budget of 2k per year * Free office meals, lunch selection from different providers * Group and individual English, Catalan & Spanish lessons as part of our working day * Private Health Insurance with Alan * Flexible working hours + Intensive Fridays * Flexible remuneration to deduct from gross salary (kindergarten/food/transport check) * Gym & Wellness plan, including physiotherapist in the office * Generous referral Program & Charity Donation * Bonus for weddings & newborns * Wallapop Renta (Tax income support) * Monthly plan for free shipping, bumps & home-pick-up on our services * Work anniversary Gifts and Birthday Surprises * Contribution towards your WIFI in your monthly payroll * One-off payment based on compensation package to go towards setting up your home office * Relocation package (monetary support and legal advice) and visa sponsorship, if applicable * 26 holidays per year * TOP hardware of your choice (latest Apple or Windows)   What does the hiring process for this position look like? 👀 Intro Call - run by talent acquisition, focus on providing more information about the role and the company as well as going over your experience, motivation, and expectations. This usually takes 45-60 minutes. Conversation with an Engineer: In this step, you will meet with a member of our engineering team. We will dive deeper into your technical background and problem-solving approach to assess if you are a strong fit for the team. It is also a great opportunity for you to ask specific questions about our tech stack and the day-to-day work. In-Person Assessment Centre (Mid-September): If selected, you will be invited to our office for a collaborative assessment centre. You will participate in exercises alongside other candidates, giving you a chance to showcase your skills, meet our team, and get a real feel for how we work.