Senior Backend Engineer (Python) - Blitz

Qonto

Our mission and customers: We are creating the freedom for SMEs to succeed by delivering Europe's leading finance workspace with banking at its core, augmented by financial tools. We are proud to be rated 4.8 on Trustpilot, based on 55,000+ reviews. Our culture puts customer satisfaction at the core of what we do, as proven by our Net Promoter Score of 75 (more about our culture here). Our journey: Founded in 2017 by Alexandre and Steve, Qonto has grown to 1,600+ Qontoers serving over 600,000+ customers across 8 European countries. We have been profitable since 2023, and we are just getting started. Our beliefs: We hire for skills and potential. With 80+ nationalities, 45% women, of which 56% of women in our leadership team, diversity isn't a program; It's who we are. We've built a discrimination-free hiring process because the best teams are built on merit. AI at Qonto: AI is deeply embedded in how we work (here) - Every Qontoer gets unlimited access to the best AI tools. We want people who experiment without waiting for permission, push AI beyond the obvious, know when to trust it, and when to question it. ------------------------------------------------------------------------------------------------------ 🌏 Location: France, Germany, Spain, or Italy — full remote-friendly. Join us as a Senior Backend Engineer to build the AI-powered tooling that enables Qonto's financial crime compliance teams to make decisions faster and with greater confidence, directly supporting our path to a full banking licence. ➡️ As a Backend Engineer at Qonto, you will Build AI-integrated backend systems: Design and ship production-grade services that connect AI models (Claude, OpenAI, or open-source equivalents) to our compliance workflows, handling prompting, output parsing, and model behaviour in a real regulated-industry context Own service architecture end-to-end: Co-own design, reliability, and scalability from day one, no PM layer between you and the technical decisions that shape the product Automate AML/AFC compliance operations: Translate compliance agent workflows into software, from EDD automation to customer onboarding acceleration, with direct feedback from the ops teams you're helping Drive continuous improvement: From production monitoring to post-mortems, you track impact, flag regressions, and improve what's in your scope with your peers and manager Shape the technical direction: In a team of 5, every engineer carries architectural weight. You'll lead design discussions, anticipate risks, and contribute to how the platform evolves ➡️ What you can expect Short time-boxes and lean process: daily goals, light Kanban, ceremonies, you spend most of your time building, not in planning meetings AI is the product, not a side tool: this team's output is AI-powered compliance tooling. You'll use Claude or OpenAI to solve real problems, and you'll be expected to handle model behaviour reliably in production, not just use AI to go faster Direct roadmap ownership: no dedicated PM means you and the team define priorities, your judgment shapes what gets built next Close feedback loop: AML/AFC ops teams proactively raise needs and respond quickly to what you ship. Lead time reduction, prediction confidence, and agent throughput are the metrics that tell you it's working ➡️ Your future team You'll join a team of 5 engineers within Qonto's Financial Crime Compliance (FCC) domain, alongside Ioannis (Tech Lead) and a mix of Senior/Staff Backend Engineers and Machine Learning Engineers. You'll be part of a 190-strong backend engineering community within a 500+ Product Engineering department. One important clarification: this team does not build fraud detection engines or KYC/KYB rule engines. Those exist elsewhere at Qonto. This team builds the automation layer on top, turning model outputs into decisions that help compliance agents respond faster. It's a backend role at the intersection of AI integration and regulated-industry operations. ➡️ About you AI integration in production: You've shipped systems where AI (Claude, OpenAI, or open-source) is a core functional component, not a coding assistant, but the product itself. Strong backend foundation: Solid experience with large-scale web application architecture and real production constraints + Ideally experience in Python. Sound architectural judgment: You make confident system design decisions independently and can articulate the trade-offs. Product instinct without a PM: You're comfortable owning the full cycle: scoping, prioritizing, shipping, success metrics 

Alma

🧡 ABOUT ALMA At Alma, we believe sustainable commerce depends on fair, well-balanced trade. Because finance plays a pivotal role in business, our mission is to put it back in its rightful place - serving merchants and consumers. Our installment and deferred payment solutions help merchants boost sales by 20% or more, increase customer loyalty, and deliver a seamless shopping experience - without encouraging bad debt. As the buy now pay later leader in France and active in 10 European countries, we've empowered over +25,000 merchants and 10 million consumers. With 380+ Almakers and €100M+ ARR, Alma is scaling rapidly across Europe as a member of the Next40, and we're just getting started!   👐 ABOUT THE TEAM We are hiring for different squads. We will direct you to a specific team depending on your interests and skills. This position is a permanent contract (CDI) based in Paris or remote from France.   💼 ABOUT THE JOB Build the payment infrastructure of tomorrow * Design and develop the APIs and backend components that power payments for thousands of merchants and millions of consumers across Europe. Raise the bar on quality, security & performance * Write maintainable, production-grade code that meets the highest standards of a regulated company processing billions of euros. Shape our technical architecture * Collaborate closely with Product and other tech leaders to evolve our architecture in line with growing business needs. Own reliability end-to-end * Lead incident response and performance troubleshooting, driving long-term improvements to ensure our platform stays resilient at scale.   🧰 YOU WILL WORK WITH Python, Docker, React, GCP, Kubernetes, PostgreSQL, Redis, Pub/Sub, Datadog   🧩 ABOUT YOU To succeed in this job * 8+ years of experience in backend engineering on large-scale systems (excluding internships and apprenticeships) * Strong proficiency in Python and relational databases — we're open to other backend languages, but Python is our core stack * Fluency in French with a solid level of English * Methodical, with strong communication and problem-solving skills; at ease working in a cross-functional environment And it will be nice if you also * Have experience building payment or financial solutions * Have a track record of influencing product and technical decisions at scale * Hold a Bachelor's or Master's degree in Computer Science or a related field Don't meet every single requirement? At Alma, we believe great hires come from diverse paths. If this role excites you, we encourage you to apply. We value potential, curiosity and the ability to grow as much as experience.   🧘 WHAT'S IN IT FOR YOU If you join, you will be able to grow and impact on: * Real-world scale — your code will directly power payments for millions of consumers and tens of thousands of merchants across Europe. * Technical ownership — you'll have genuine influence over architecture decisions, not just implementation. * A regulated, fast-moving environment — you'll tackle the unique challenges of building robust, secure fintech infrastructure in a company that's still moving fast.   🤑 COMPENSATION & BENEFITS * Competitive salary based on 12 months * Profit-sharing and employee savings plan * Health insurance: 100% covered by Alma including family package * Disability insurance: 100% covered by Alma * Sport: partnerships with Gymlib and Classpass, or €30/month reimbursement for your sports activities * Maternity/paternity leave: salary maintained at 100% during leave with no seniority requirement. Return to work at 4/5 schedule paid at 100% for 8 weeks. * Sustainable Mobility Package (FMD): €544.80/year (excluding full-remote contracts) * Meal vouchers: €10/day, 50% covered by Alma * Mental health: free access to MindDay platform * Paid time off: 25 days/year (+ additional paid leave granted for employees on executive contracts) * Access to our Learning & Development Platform * 2 weeks of full remote possible per year in summer   🎯 INTERVIEW PROCESS * Video call with a Talent Acquisition team member to understand your path, motivation & present you the role. * Video call with your future manager to deep dive the role, the team, your profile and answer all your questions. * Take-home coding test, followed by a remote feedback session. * Live system design interview to assess your practical and architectural knowledge. * A coffee chat with the squad you’ll join to further assess your skills and team fit. More information on the hiring process can be found in our Interview Guide.   🌍 DIVERSITY & INCLUSION At Alma, we believe that diversity fuels innovation and makes our community stronger. We are committed to building a workplace where every person feels seen, respected, and empowered to do their best work whatever their gender, background, ethnicity, age, sexual orientation, religion, disability or lived experience. As an equal opportunity employer, we welcome applicants from all walks of life, and all employment decisions are made based on qualifications, merit, and business needs.

Voodoo

ABOUT VOODOO Founded in 2013, Voodoo is a tech company that creates mobile games and apps with a mission to entertain the world. Gathering 800 employees, 7 billion downloads, and over 200 million active users, Voodoo is the #3 mobile publisher worldwide in terms of downloads after Google and Meta. Our portfolio includes chart-topping games like Mob Control and Block Jam, alongside popular apps such as BeReal and Wizz. TEAM The Engineering & Data team builds innovative tech products and platforms to support the impressive growth of their gaming and consumer apps which allow Voodoo to stay at the forefront of the mobile gaming industry. The Voodoo Ad-Network is an autonomous product group of around 60 highly driven professionals with an ambitious mission: building top-tier ad network services. Our primary goal is to leverage Voodoo’s massive first-party data ecosystem to optimize and scale monetization. We are in a rapid growth phase, expanding into new ventures such as opening to external inventory, penetrating the external advertiser market, and driving social network monetization following our recent acquisition of BeReal. To support this incredible trajectory and promising early results, we are scaling our team. The Feature Platform Team is the foundational infrastructure engine empowering our ML Ads Recommendation capabilities. Drawing inspiration from industry-leading feature stores, we build and maintain the unified data layer for our machine learning features. Our mission is to accelerate the ML lifecycle by providing a unified, scalable, and highly available architecture for computing, storing, and serving batch, real-time, and on-demand features. Beyond just building the infrastructure, we are a highly proactive team that continuously explores new data signals and feature engineering opportunities to push the boundaries of our targeting performance. This role is a hybrid position, either based in Helsinki, Paris or Strasbourg. ROLE We’re looking for a Senior Data Engineer to join our Feature Platform Team. You will be joining a dedicated squad of Data and ML Engineers focused on guaranteeing consistency across offline training and online inference, eliminating training-serving skew, and enabling our Data Scientists to seamlessly and rapidly deploy the next generation of high-performing models. In this role as a Senior Data Engineer, your scope extends far beyond classical data engineering. You will be responsible for managing both the offline and online components of our machine learning architecture. This means bridging massive-scale data processing (handling both heavy batch jobs and subsecond real-time feature updates) with high-load online services that must process and return features for inference with strict low latency. * Architectural Ownership: Take end-to-end ownership of highly visible projects from initial ideation to production release. This includes feature scoping, timeline estimation, architecture design, and benchmarking next-generation technologies. * Proactive Data Innovation: Go beyond passive implementation by actively partnering across the entire data lifecycle. You will deeply understand the downstream Data Science domain to discover high-impact feature opportunities, while also collaborating closely with upstream data engineering teams to understand ingestion mechanisms (right up to the SDK and Bidding platforms) to unlock and integrate new data signals. * ML Infrastructure & Feature Platform: Collaborate closely with Data Scientists and ML Engineers to design, scale, and optimize core components spanning both offline training and online inference, including our Feature Store (supporting batch, streaming, and low-latency on-demand computation) and engines for on-demand training dataset generation. * Pipeline Engineering: Build, maintain, and optimize mission-critical data pipelines spanning both extensive batch processing and continuous real-time streams (ensuring subsecond feature updates) to adapt to ever-evolving business and machine learning needs. * High-Performance Online Services: Actively build and maintain the high-load backend applications that power our ML model serving, ensuring they can process and return features with low latency and high availability under heavy traffic. * Scalability & Performance: Work hand-in-hand with our infrastructure teams to guarantee the reliability, security, and immense scalability required for an ad-network ecosystem. * Agile Collaboration: Thrive in a fast-paced agile environment with rapid decision-making processes. You will collaborate daily with back-end developers, data scientists and product managers. * Mentorship & Team Culture: You will actively contribute to our engineering culture, share knowledge, and ensure every team member feels comfortable, supported, and empowered to grow in their role. PROFILE We are looking for a Senior Data Engineer who deeply understands both the data lifecycle and the specific challenges of putting machine learning models into production at scale. * 6+ years of proven experience as a Data Engineer, ML Engineer, Backend Engineer, or a closely related role in a high-scale environment. * Big Data & Streaming Mastery: Extensive hands-on experience working with Flink or Spark at scale. Deep expertise in Flink (or similar stateful streaming platforms) as you will be a key contributor in scaling our real-time streaming architecture. * Coding Proficiency: Advanced expertise in Python for robust ETL pipelines and custom feature-definition SDKs/DSLs * Experience or a strong willingness to work with Golang for building high-performance, low-latency backend applications as well as familiarity with Java is highly valued for our Flink streaming workloads. * Data Architecture: Deep understanding of modern Data Lakehouse design principles, open table formats (like Iceberg), optimization techniques, and data modeling. * Cloud & DevOps: Strong hands-on experience with a major cloud platform (AWS, GCP, Azure, etc.), though AWS is our preferred environment. Familiarity with DBT for data pipeline transformation is a plus. * ML Production Awareness: You have a solid grasp of the unique challenges involved in running ML models in production, including working with Feature Stores, mitigating training-serving skew, and model monitoring. * System Design: You are highly familiar with topics surrounding system scalability, high availability/reliability, low-latency API design, and security best practices. OUR STACK * Languages: Python (ETL & SDKs), Golang (High-Performance Online Services), Java (Flink) * Processing & Orchestration: Spark, Flink (Real-time Streaming), Airflow, DBT * Storage & Infrastructure: Apache Iceberg, Amazon Web Services (AWS), Kubernetes, Terraform BENEFITS * Competitive salary based on experience * Swile Lunch voucher * Gymlib (100% covered by Voodoo) * Premium healthcare coverage with SideCare, 100% covered for you and your family * Wellness activities in our Paris office * Remote Fridays