Senior Python Engineer

Synthflow AI

Synthflow AI is an enterprise AI agent platform that unifies customer operations across voice, chat, and messaging. Our agents handle routine interactions at scale so teams can focus on high-value work. * Over 20M hours of operations automated * 60% more calls answered vs. non-AI operators * 150M interactions handled, 99.99% uptime Backed by Accel, Atlantic Labs, and Singular. Trusted by 1,000+ customers. Recognized as one of the most promising companies in Germany. About the role: We’re looking for a Senior Python Engineer to craft reliable, production-ready software and backend systems, with a strong emphasis on databases, scalable APIs, and engineering fundamentals. Your responsibilities will include: * Develop and maintain our backend infrastructure, focusing on scalability, performance, and reliability. * Design and evolve data models and persistence layers with a strong focus on PostgreSQL and database best practices (schema design, migrations, query performance, indexing, transactions). * Build and maintain enterprise-grade APIs (e.g., FastAPI), including versioning, authentication/authorization, and observability. * Engage in pair programming to improve code quality and collaboration. * Manage deployments and environments using Kubernetes and GitOps practices (ArgoCD). * Conduct code reviews, providing constructive feedback and upholding best practices. * Contribute to product delivery end-to-end, including occasional work on front-end features when needed. You have: * 5+ years of experience as a Python developer, shipping production systems. * Strong experience building scalable and extensible data infrastructure. * Deep familiarity with relational databases, especially PostgreSQL (performance tuning, migrations, transactions). * Experience building and maintaining enterprise-grade APIs with FastAPI. * Hands-on experience running production workloads on Kubernetes. * Experience with Argo CD (GitOps deployment workflows). * Experience with GitHub Actions. * Proficiency in cloud environments (preferably GCP or AWS). Nice to have: * Ability to contribute to front-end work (not necessarily a front-end specialist), ideally with React/TypeScript. * Golang experience, with willingness to contribute to our orchestration stack, which is built in Go What we offer: * Autonomy at speed: High-ownership roles in a fast-moving startup. * Engineering-first environment: Work on foundational systems that directly impact reliability and scale. * Career growth: Scale your impact as the company grows. * Rewarding package: Competitive pay, equity options, and comprehensive benefits that reflect your skills and experience. Founded in Berlin in 2023 by serial entrepreneurs Albert Astabatsyan, Hakob Astabatsyan, and Sassun Mirzakhan-Saky, Synthflow AI democratizes access to advanced voice AI with a no-code platform that lets enterprises easily create, deploy and scale natural-sounding, cost-effective voice agents tailored to their business needs.

Sumup

TEAM DESCRIPTION The Risk AI Engineering Squad is a cross-functional team within the Risk & Compliance tribe,  responsible for developing cutting-edge data products and ML solutions that power Transaction Monitoring and protect our merchant base from Money Laundering and Financial Crime. We combine automation, AI, and engineering excellence to build innovative products that empower Risk and AML teams to work smarter, faster, and more efficiently. The Senior Data Scientist role is critical to advancing our transaction monitoring capabilities through machine learning, feature engineering, and scalable model pipelines. You will work across the full model lifecycle — from typology understanding and data exploration to feature development, training, validation, deployment, and monitoring — helping ensure our Risk and AML controls remain effective, auditable, and compliant across products and markets. We actively welcome applications from women and people from underrepresented backgrounds. Diverse perspectives make our team stronger and our systems more robust. If you're motivated by technical depth, real-world impact, and the challenge of making ML work reliably in a high-stakes environment, this role is built for you. Join us to shape the future of financial safety and make a lasting impact! WHAT YOU'LL DO * Build and ship production ML systems end to end: own and evolve end-to-end batch training pipelines, model versioning, monitoring, model deployment, and rollback for transaction monitoring models. * Build, maintain, and improve ML models for transaction monitoring, focusing on detection quality, operational efficiency, and regulatory compliance * Engineer features mapped to AML and Fraud typologies and suspicious behaviours, working closely with Risk investigators to translate domain knowledge into alerting logic and threshold calibration * Run sensitivity tests on synthetic datasets, produce ML governance artefacts such as model cards, and deliver audit-ready documentation to meet regulatory expectations * Own and evolve the AML Risk Score by analysing driver contributions, monitoring drift, running back-testing, and recommending improvements to features, logic, and thresholds * Partner with AML and Fraud Operations, Product, and Engineering to translate stakeholder needs into actionable, scalable data science solutions * Track and improve detection performance metrics, adapt solutions to regional compliance requirements, and contribute to system design documentation YOU'LL BE GREAT FOR THIS ROLE IF YOU HAVE… MUST HAVE * Production Python engineering: you write code that ships — you're comfortable with CI/CD, automated testing, versioning, and monitoring in a real production environment * End-to-end ML pipeline experience: demonstrated experience deploying and operating ML models in production, including drift monitoring and rollback * Modelling and productionalizing models: demonstrated experience training ML models, choosing appropriate KPIs and metrics for evaluation. * Data engineering fundamentals: hands-on experience with complex, multi-source data ecosystems, data quality, and lineage * Clear, confident communication: ability to align cross-functional stakeholders, set expectations, and turn ambiguous compliance requirements into a concrete technical plan NICE TO HAVE * Experience with Pyspark * Experience in AML, fraud detection, or financial crime domains * Unsupervised machine learning (e.g. anomaly detection, clustering) * Familiarity with Feature Stores and alerting threshold calibration * Experience producing regulatory ML governance artefacts (model cards, audit documentation) * Experience with AI systems and tooling WHY YOU SHOULD JOIN SUMUP * 🌎 Opportunity to work with SumUppers globally on large-scale fintech products used by millions of businesses worldwide, from our Berlin office. This involves an office-first setup * 🌈 Commitment to Diversity and Inclusion: be part of a workplace that values and promotes diversity, fostering an inclusive environment where everyone's perspectives are respected and embraced * 🚀 Enrolment onto our Virtual Stock Option programme: you will own a stake in SumUp's future success * 📚 A dedicated annual L&D budget of €2,000 for your individual development, which can be used to attend conferences and/or advance your career through further education * 💶 A corporate pension scheme where we match up to 20% of your contributions * 🏖️ Generous time off: enjoy 28 days of paid leave plus public holidays and special leave days * 💪 Numerous other benefits such as Urban Sports Club subsidy, Kita placement assistance, and subsidised office lunches * 🌴 Break4me: 1-month sabbatical after 3 years of service * 🔗 Referral Bonus: earn additional rewards by referring talented individuals to join the SumUp team ABOUT SUMUP Be empowered to do more that matters. At SumUp, we're on a mission to empower small businesses across the globe by providing simple and affordable tools that allow them to thrive. Today, over 4 million businesses in 37 markets rely on SumUp as their financial partner to manage payments, finance and customer relationships. Our commitment to small businesses is reflected in our diverse team of over 3,000 SumUppers from over 90 nationalities, united by global collaboration and an innovative mindset. Our core values lay the foundation for who we are and what we stand for, shaping our work culture and driving our success. We foster inclusivity and a continuous learning culture, providing a safe space for personal and professional growth. Our differences make us unique and strong as we strive to create an environment where everyone belongs and feels supported, no matter how they identify. SumUp is proud to be an Equal Employment Opportunity employer, actively seeking and embracing diversity in our workforce. We don't make hiring or employment decisions based on race, colour, religion or religious belief, ethnic or national origin, nationality, sex, gender, gender identity, sexual orientation, disability, age or any other basis protected by applicable laws or prohibited by company policy. Our commitment extends beyond recruitment to creating a safe and respectful workplace where harassment of any form is strictly prohibited. Discover more about our culture and opportunities on our careers website, and follow our journey on LinkedIn, Instagram, and TikTok. Job Application Tip We recognise that candidates feel they need to meet 100% of the job criteria in order to apply for a job. Please note that this is only a guide. If you don’t tick every box, it’s ok too because it means you have room to learn and develop your career at SumUp.

Doctolib

WHAT WE DO Join a team of passionate and hardworking entrepreneurs to transform healthcare! Working in the tech team at Doctolib involves building innovative products and features to improve the daily lives of care teams and patients. We work in feature teams in an agile environment, while collaborating with product, design, and business teams. WHAT YOU'LL DO We are looking for a Senior AI Engineer (Python) to join the Conversational AI (CAI) team in the Practice Efficiency domain. As a Senior AI Engineer, your mission will be to build and scale a new product in the Doctolib suite: our Phone Assistant, with the vision to revolutionize access to care for patients and day-to-day practice management for practitioners. This opportunity will allow you to leverage the latest technologies in AI, NLP, and speech recognition to build delightful user experiences and scale your product to millions of users. Your responsibilities include but are not limited to:   * Design, ship, and operate production-grade agentic LLM systems that improve patient-practitioner interaction and streamline healthcare workflows * Validate hypothesis with offline evaluation datasets and A/B tests on real traffic * Partner with other machine learning teams to design and improve evaluation pipelines, security/safety guardrails, and metrics * Develop and maintain core agentic capabilities, including memory, reasoning orchestration, and tool adapters, ensuring strong observability, fallback mechanisms, and fail-safe behaviors * Own performance, observability, and security: monitoring dashboards, SLO/SLI, security posture * Ensure privacy and security by design * Contribute to cross-functional initiatives that shape Doctolib's future AI platform and best practices in building agentic systems that will reinvent the work of health professionals and improve people's health ABOUT OUR TECH ENVIRONMENT * Our solutions are built on a single, fully cloud-native platform that supports web and mobile app interfaces, multiple languages, and is adapted to the country and healthcare specialty requirements. To address these challenges, we are modularizing our platform run in a distributed architecture through reusable components. * Our stack is composed of Rails, TypeScript, Java, Python, Kotlin, Swift, and React Native. * We leverage AI ethically across our products to empower patients and health professionals. Discover our AI vision here! WHO YOU ARE Are you convinced that you have exactly what it takes for the position? Then we encourage you to apply. Even if you don't meet every requirement, you might be exactly the right future Doctoliber for this or other positions! Before you read on - if you don't have the exact profile described below, but you feel this job description matches your skill set, we still encourage you to apply.   * You have 6+ years of experience as a software engineer, with significant experience using Python * You have a track record of experience with the full lifecycle of an AI product at scale, from initial evaluation and launch to iterations based on results in production * You understand and promote best practices related to the software development life cycle, such as automated testing, good use of CI/CD, and DevOps practices (you build it - you run it) * You are product-oriented and comfortable guiding your teammates to suggest tradeoffs to balance business needs with technical constraints * You are very focused on code quality and have a rigorous testing culture * You are eager to share your knowledge and help the team grow by pair programming and mentoring * You are comfortable speaking & writing in English in your day-to-day with the team Now, it would be fantastic if you:   * Have experience with agentic systems in production * Have experience in the medical domain WHAT WE OFFER * A Deutschlandticket (Germany-wide public transport pass) fully paid for by Doctolib * 28 vacation days + 1 additional day for each full calendar year of employment (up to a maximum of 30 days) * Work from abroad for up to 10 days per year thanks to our flexibility days policy * Company health insurance with great supplementary benefits through our partner Allianz * Company pension scheme (bAV) through Allianz with an employer subsidy of 40% (15% within the probationary period) * Enrollment in Doctolib's long-term employee value sharing plan called DoctoGrowth * The Doctolib Parent Care program, which includes one month additional parental leave and much more * Free mental health and coaching services through our partner Moka.care * Subsidized sports membership through our partner Urban Sports Club * A flexible workplace policy offering both hybrid and office-based mode * Alongside healthy snacks and our regular breakfast buffet, we provide a subsidized meal benefit * For caregivers and workers with disabilities, a package including an adaptation of the remote policy, extra days off for medical reasons, and psychological support THE INTERVIEW PROCESS * Recruiter Interview * Feature Building Interview * AI System Design Interview * Behavioral Interview * Reference check * Offer! JOB DETAILS * Full-time * Location: Berlin * Working mode: Hybrid * Start date: as soon as possible If you would like to find out more about tech life at Doctolib, feel free to read our latest Medium blog articles! At Doctolib, we are committed to improving access to healthcare for everyone. This translates into our recruitment process. We evaluate candidates based solely on qualifications and motivation, without any form of discrimination. The more diverse ideas are heard, the more our product will truly improve healthcare for all. You are welcome to apply to Doctolib, regardless of your gender, religion, age, sexual orientation, ethnicity, disability. To ensure equal opportunities, we invite you to exclude personal information (e.g. pictures, age) from your applications. If you require any accommodation, please let us know for support during the hiring process.  Join us in building the healthcare we all dream of! All information provided is processed by Doctolib for application management. For data processing details, click here. Please contact hr.dataprivacy(at)doctolib.com for inquiries or to exercise your rights.