Senior Backend Engineer – Identity & Core Product (m/f/d)

Content Pass

THE MISSION We are an established, profitable company in the privacy and adtech space - helping publishers and media houses across Europe offer cross-publisher monetization models. Our technology powers multiple billion page impressions every month, and we’re scaling fast into new markets. We combine the best of both worlds: the stability of a profitable business and the agility and ownership mindset of a startup. Every team member has a visible impact and we encourage you to shape not just our products but also our culture. We are looking for a Senior Software Engineer to take ownership of our SDK - the core component integrated into partner websites. This SDK manages communication with CMPs (Consent Management Platforms) and our stack, ensuring privacy compliance, performance, and reliability at scale. You’ll be responsible for evolving the SDK into a high-performance, secure, and extensible framework that can: * Integrate with additional CMPs * Unlock access to premium content models * Potentially detect and block 3rd-party requests, ads, and trackers  This role is ideal for an engineer who thrives at the intersection of web performance, browser internals, and privacy technology - someone who takes pride in writing elegant, efficient, and secure TypeScript code. What You'll Do * Own the design, development, and evolution of our web SDK used across publisher integrations. * Ensure high performance, reliability and scalability for billions of monthly impressions. * Work closely with the whole engineering and product teams to extend SDK functionality for new CMPs and features. * Debug complex browser and integration issues across different environments. * Champion best practices for security, maintainability and developer experience. * Collaborate cross-functionally with other engineers and stakeholders to ship improvements quickly. YOUR PROFILE Required Skills & Experience * 5+ years of professional software engineering experience. * Deep understanding of JavaScript/TypeScript and modern web APIs. * Strong experience debugging in complex, cross-browser environments. * Solid understanding of browser networking, cookies, privacy and security mechanisms. * Experience building SDKs, libraries or embeddable scripts at scale. * Excellent communication skills and ownership mindset - you ship and iterate fast. * You care about understanding how things work and improving them, not just completing tasks. * Strong English communication skills in written and verbal communication - you thrive in explaining technical challenges to your peers. Mindset * Intrinsic motivation - you care about why, not just what. * Curiosity and eagerness to learn - you stay up-to-date with technology trends and share it with the team. * Ownership mentality - you take responsibility and follow through. * Pragmatic problem-solver - you value clarity, simplicity, and maintainability. * Product-focused thinking - you consider the real-world context and user impact behind the code. Nice-to-Have * Familiarity with privacy tech, adtech, or CMP integrations. * Experience with APIs and caching layers. * Familiarity with Node.js and modern CI/CD environments. * Interest in performance profiling, browser automation or content blocking. WHY US? Why You’ll Love Working Here * Impact: Your work directly affects billions of web requests monthly and that makes you proud. * Ownership: Take the lead on a mission-critical SDK with real autonomy. * Flexibility: Remote-first culture, flexible working hours and async-friendly communication. * Growth: Be part of a profitable, scaling company entering new markets. * Equity Upside: Participate in our beneficiary share program. * Culture: A collaborative, fast-moving team where new ideas are encouraged and deployed fast.

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:                 ----------------------------------------------------------------------------------------------------------------------------------

lemon.markets

ABOUT LEMON.MARKETS 🍋 We enable anyone to be an investor. Our mission is to grow investing opportunities for all European customers and businesses. By empowering FinTechs, banks, and wealth managers to offer investment products, we help create financial well-being for their customers. lemon.markets is a Brokerage-as-a-Service platform: simple digital access to capital markets through a single API. Our API-first infrastructure abstracts brokerage complexity with a well-documented API, a self-service customer operations portal, and a clear regulatory framework, so partners can launch customer-centric, compliant products in weeks, not months. As part of the dwpbank group, we’re adding a layer of resources and expertise to benefit from, while continuing to operate as an independent fintech with our own team, product, and start-up identity under the dwpbank umbrella. YOUR MISSION: As a Backend Engineer at lemon.markets you will play a key role in designing the backend services and architecture of our brokerage API platform that allows other companies to easily embed investing into their product. You will take ownership of features and services end to end in cross-functional teams, ensuring they run smoothly on production. You will focus on areas of the Customer Lifecycle, Investing or Banking processes - making sure our Core Platform & Systems around it are reliable & scalable. Our Tech Stack is Python, FastAPI, AWS and Postgres. While you can have worked in different modern tech stacks prior, you should be excited to work in Python and learn it if you haven’t worked with it before. You will have a significant impact on the development of our core Platform & Systems - and thereby architectural decisions, as well as on the business itself. Work alongside a cross-functional team of experts, and together we will leverage your previous experiences to build the investment infrastructure for the next 100 million retail investors in Europe. ABOUT YOU: * You have the ability to write well-structured and tested code in more than one high-level programming languages like Python, Golang, Java or Ruby, plus another language such as Javascript or Typescript. * You have experience in designing and implementing highly scalable architecture and reliable REST APIs and bring the desire to make them world-class. * You’ve gained good experience with software in a cloud environment (AWS, GCP, Azure) and the architectural patterns for this environment. * You have a good understanding of more than one document-based or relational database technology such as MySQL/PostgreSQL or MongoDB * You know how to write high-quality code that is understandable, maintainable and well tested, and can guide other engineers to do the same via code reviews. * You have good problem-solving skills and the ability to provide in-depth evaluations and analyses of unique and complex technological issues. * You have a track record of designing, building and operating reliable and scalable backend systems as part of a cross-functional team. YOU WILL BE SUCCESSFUL IN THIS ROLE IF: * Growing investment opportunities excites you. We operate in a highly regulated environment and therefore having worked prior in a Fintech or financial Service provider would give you a head start, but is not a must. * You see yourself as a product engineer. That means, you are excited by solving customer problems and strive to become an expert in the domain area you are working in. * You enjoy building from scratch. This means high involvement in the product development process itself while advocating for the best engineering practices. It also means that you enjoy taking technical decisions. * You are ready and willing to take ownership of problems and act on them decisively with no supervision. You always thrive for high quality outcomes through focus, determination and attention to detail. * You are a team player. Working together as a team, sharing knowledge & providing mentorship comes naturally to you. Long term - you consider becoming a team lead. * You have no problem with learning new technologies on the go. You try to solve problems with more things than the ones you already know. We will always enable you with that, but your willingness has to come first. * You understand what working in a startup or a similar lean organisation is like. You are able to work with a small team in a lean environment, can move quickly and focus on what's truly important. * You see yourself reflected in the skills above, or you see yourself growing into this path. We're looking for people with passion, desire to learn and that are team players. You're encouraged to apply, even if your experience doesn't precisely match the job description. Your skills and passion will stand out - and set you apart - especially if your career has taken some extraordinary twists and turns. HOW WE TAKE CARE OF YOU: * 🚀 Compensation package: We offer you a competitive salary, based on your experience and the value-add you bring to lemon.markets. * 🕑 Flexible working hours: We trust people to choose when they work best and avoid a rigid 9 to 5 mindset. You decide on the rhythm that helps you do your best work, with only shared core hours from 12:00 to 16:00 to support collaboration. * 🏢 Hybrid work setup: You can work from anywhere in Germany within a hybrid model. At the same time, in-person collaboration is a key part of our culture. That being said, individual contributer lemoneers work 4 days or more per month on-site in our Berlin office, spending quality time together with the team at events, onsites/offsites or over team dinners. * 📈 Grow with us: We take your personal development seriously! You’ll get regular mentorship and stretch opportunities, plus a clear career development framework with frequent feedback conversations so you always know where you stand, and what to do to level up. * 🌱 People & culture: You’ll feel our culture in the small things, like polaroids from our lemoneers’ first day, Friday food market strolls at Maybachufer, and our monthly new-joiner breakfast. But also in the bigger things: celebrating the onboarding of new partners, growing our teams, and owning a strong discussion culture. * 💛 Perks & benefits: We choose benefits that add actual value. We sponsor a Deutschlandticket for employees on unlimited contracts, plus 50% off on Beatvest - our partner for financial education and investing. * 🏝 Workation: Get out of here! At lemon.markets you can work remotely from anywhere in the EU for up to 10 consecutive days at a time, and up to 60 days per year in total. As an equal opportunity employer, lemon.markets is committed to building an inclusive workplace. The company welcomes people from all different backgrounds, including age, citizenship, ethnic and racial origins, gender identities, individuals with disabilities, marital status, religions and ideologies, and sexual orientations to apply. If you feel this role could be a great match for you even if you don’t tick every box, we’d still love to hear from you, please apply. You have any questions? Feel free to contact us via talent@lemon.markets.com