Senior Software Engineer FullStack Kotlin / React - Berlin (f/m/d)

Working Student - Product Engineer
Over 4 million merchants use our card readers to process payments in 34 countries. As we build a world where every business can thrive, we continually expand our range of products and services. We are a truly global fintech company, with 3,000+ people from 93 nationalities spread across 22 offices on four continents.

As the People Tech team, our mission is to enable long-term scalability by fostering a data-informed culture through seamless systems and a people-centric employee experience. As our Product Engineer - Working Student, your first mission will be to help us rethink Feedback and Team Reviews: learn how the process works today, find the friction and turn promising ideas into product experiences that colleagues can test.

The work starts frontend-first: build realistic prototypes in React, Next.js or similar and explore a simpler product layer over Workday, our system of record. If a direction proves valuable, you may help grow it into a standalone internal app - from interface and APIs to data models, authentication and integrations - alongside People Tech and engineering partners.

This is a real product challenge, not a side quest: you will learn across discovery, UX, frontend, testing and product decisions, supported by mentorship and code review. You will collaborate with Product Owners, process owners, people tech and workday specialists, sumuppers, managers, people partners, people analytics and senior stakeholders, with potential exposure to backend development, integrations and production delivery. If your favourite way to answer “what if?” is to build it, you will fit right in.

What You’ll Do

• Find the right problem: Speak with process owners, employees and managers to understand Feedback and Team Reviews, identify friction and decide what is worth solving first.
• Shape a focused product slice: Turn requirements, questions and constraints into clear user journeys and an MVP that can teach us something useful.
• Prototype and iterate quickly: Build realistic frontend experiences in React, Next.js or similar; compare directions, test assumptions and adjust when the evidence points somewhere better.
• Design for different kinds of work: Create accessible, intuitive flows for office-based teams, metrics-driven Field Sales colleagues and on-site teams without building three separate products.
• Think end to end: If the concept is validated, help evolve it towards a standalone app while considering APIs, data, authentication, privacy, deployment, integrations and what should remain in Workday.
• Use AI as a co-pilot, not an alibi: Use tools such as Cursor, GitHub Copilot, v0, Lovable or similar to accelerate development while still understanding, checking and owning the result.
• Make the learning visible: Demo your work, explain decisions and trade-offs, respond to feedback and document the findings and technical choices that should shape the next version.

You’ll be great for this role if

• Student status. You are currently enrolled at a university and available for a part-time role based in Berlin.
• Modern web development skills. You have built web applications with React, Next.js or a similar frontend framework. Coursework, internships, hackathons, personal projects and portfolio work all count.
• Product-minded builder. You care about the user’s goal and accessibility, and can turn an ambiguous problem into the simplest useful solution, test it and iterate.
• Full-stack and AI curiosity. You want to learn how APIs, data and services turn an interface into a reliable product, and can use AI-assisted tools while still understanding, checking and owning the result.
• Clear, team-first communication. You can explain what you built end to end, make technical choices understandable, ask for input and respond well to feedback.

Nice to have

• Backend and integration foundations. Some experience with Node.js, TypeScript, Python, databases, APIs, serverless functions, Supabase, Firebase, AWS or comparable technologies.
• Identity and data concepts. A basic understanding of OAuth, SSO, permissions or responsible data handling.
• What we don't expect: years of professional experience, previous Workday knowledge or a perfect first attempt. If you do not tick every box, please apply anyway and show us what you can build, how you think and how you learn.

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.

About the Role

As a Software Engineering Intern at SANOVIO, you’ll get hands-on experience building the AI-powered procurement infrastructure that tackles one of the biggest and most complex cost problems in European healthcare.

This is a fast-paced, hands-on role for aspiring engineers with high agency, strong technical curiosity, and a builder mindset. We’re looking for a full-stack generalist with a frontend affinity. You’re eager to design user flows and implement them in React and TypeScript, while learning to own outcomes end-to-end across backend, data, AI-enabled workflows, and cloud deployment. You thrive amid uncertainty, move quickly, and care deeply about writing clean, high-quality code.

If you are a passionate builder who thrives at the intersection of full-stack development and AI, this is your opportunity to work directly with the founders, contribute to a real product, and grow rapidly in a startup scaling toward €10M ARR in 2026.

Tasks

• Contributing to end-to-end product workflows, from frontend UX to backend systems, data pipelines, and edge cases

• Building frontend experiences in React and TypeScript alongside scalable, reliable backend systems

• Supporting the design and development of AI-enabled systems, including embeddings, retrieval, and agents that create real operational leverage

• Working on data pipelines for large-scale unstructured data

• Making pragmatic technical decisions on architecture, tools, and frameworks to balance speed and quality

• Deploying and maintaining software in cloud environments with a “you ship it, you run it” mindset

• Writing clean, maintainable, and well-tested code with scalable, reusable components and APIs

• Collaborating across the stack and learning through code reviews, pair programming, and mentorship from senior engineers

Requirements

We are looking for ambitious engineering students or recent graduates with a strong foundation in software engineering and a genuine interest in AI. We hire for skill, ownership, and output.

General Profile

• Generalist mindset with a frontend affinity, eager to build across backend, data, and AI

• Proactive and self-driven, able to turn unclear requirements into shipped software

• Fast learner who picks up new technologies and frameworks quickly

• Comfortable iterating closely with users and clients, including across different cultures

• Strong problem-solving ability and attention to detail

• Motivated to build excellent software in a fast-paced startup environment

• Willing to work in-person in Munich with a higher intensity than a traditional 9–5 role

Technical Skillset

• Solid foundation in full-stack software engineering, especially React and TypeScript, with a good understanding of constructing user flows

• Backend engineering skills, ideally with Node.js, and familiarity with APIs and data modeling

• Experience building software projects (academic, personal, or professional)

• Familiarity with Docker and cloud environments is a plus

• AI experience is a plus, especially embeddings and retrieval, structured outputs and tool calling, evals, and agentic workflows beyond prompt engineering

Communication & Ownership

• You take initiative and enjoy taking responsibility for your work

• You communicate clearly and are comfortable interacting with technical stakeholders and clients

• You actively seek feedback and want to improve rapidly

Bonus if you

• Can share a portfolio of projects, shipped products, or a GitHub with meaningful work

• Have built workflow-heavy B2B products, internal tools, or operations software

Benefits

• Great
  central office in Munich
  with regular
  team events and dinners

• Monthly
  Wellness budget

• Access to any
  AI or productivity tools
  you need to do your best work

• International scope & travel

• Flexible work setup
  with
  time-zone responsibility

• Full-time offer opportunity

About the interview process

Step 1: Intro Call

Casual intro meeting with one of the founders to get to know each other and introduce SANOVIO.

Step 2: Technical Interview

The technical interview consists of two parts:

• A take-home exercise, including a short presentation

• A system design interview

For the take-home exercise, we’ll provide you with a task focusing on a real SANOVIO workflow and user flow in React and TypeScript, with a light end-to-end angle such as API integration, data modeling, edge cases, and clean architecture. Later, you’ll present your results to us.

Step 3: Personal Fit

Meet another co-founder to get a feel for our culture and working style.

Step 4: Offer

If we see a great fit, you’ll receive an offer.

We’re excited to see your application and get to know you!

Noel, Alex & Yong

The Founder Team

bd operations GmbH
is a European provider of IT solutions for public transport and operator of
toll services
and traffic management solutions
seated in Augsburg
.

We offer car drivers simple and digital access to the European toll network, provide them with toll products and handle the simple online billing of toll fees.

With one-stop solutions, we cover the entire value chain of customers from all over the world.

We offer a unique opportunity for IT talents to move to
Augsburg
in Germany.

Tasks

• Further development and maintenance of our web applications (backend, database, ...).

• Development of new features for our digital toll portals with state-of-the-art technologies.

• Optimisation and scaling of the system in a service-oriented architecture.

• Observance of our quality standards by actively participating in code reviews.

Requirements

• Good knowledge
  of PHP and SQL is
  required.

• Experience with a framework (such as
  Laravel
  ) is an advantage.

• Initiative and motivation to advance the product, the team and personal development.

• Contributing your own experience and ideas to the team.

• Fluent English skills.

Benefits

• 2,000 € compensation
  at the start for your relocation to Germany.

• Choose your own hardware

• Free
  German language classes (optional)

• An interesting full-time position with high responsibility within one of our growing markets.

• Possibility to proactively collaborate in a
  highly qualified, agile and very familial team
  .

• An
  international working environment
  and exciting challenges with room for new ideas.

• Possibility to participate in regular
  training programmes
  (technical and personal development).

• Start date: as soon as possible.

Wir sind
creatision
eine Digitalagentur für den deutschen Mittelstand, die sich auf die Entwicklung hochmoderner Enterprise-Lösungen spezialisiert hat. Mit dem Fokus auf CoreMedia- und Magnolia-Projekte stehen wir für moderne DXP und bevorzugen Headless-Ansätze. creatision ist eine Marke der Wertefest GmbH.

Du bist ein erfahrener Experte, der sein technisches Know-how gezielt in Beratung und Implementierung einsetzt? Dann suchen wir dich, um gemeinsam an spannenden und zukunftsorientierten Projekten zu arbeiten.

Aufgaben

• Beratung von Kunden hinsichtlich technischer Lösungen und Strategien.

• Anleitung von Entwicklern bzw. Übernahme der Projektkoordination kleinerer Entwicklungsprojekte.

• Entwurf von Architekturen und Konzeption der Umsetzung.

• Entwicklung moderner, dynamischer Webapplikationen z.B. auf Basis von CoreMedia CMS oder Magnolia CMS oder für Webapplikationen mit KI-Technologien.

• Logikimplementierung im Backend mit Java und Spring.

• Frontend-Implementierung mit React und Next.js.

• Integration von Backend-Services mit REST / GraphQL.

• Durchführung von Code-Reviews und Qualitätskontrollen.

• Anwendung agiler Prozesse und Methoden.

• Anleitung und Know-how-Transfer der Kollegen.

Qualifikation

• Nachweisliche Fähigkeit, Kunden professionell und fair zu beraten, um gemeinsam mit ihnen erfolgreiche Projekte zu realisieren.

• Klare, offene und wertschätzende Kommunikation.

• Grundsätzliches Interesse an Führung und Koordination von Menschen.

• Mindestens 2 Jahre Erfahrung in der Koordination von Entwicklungsprojekten im Rahmen z.B. einer Tech-Lead oder Architekten-Position.

• Mindestens 5 Jahre Erfahrung in der Fullstack-Entwicklung mit Schwerpunkt auf Java und Spring.

• Umfangreiche Kenntnisse moderner Webtechnologien, einschließlich TypeScript und React.

• Expertise in einem Java-basierten Content-Management-System, idealerweise CoreMedia oder Magnolia, optional Experte in der Web-Applikationsentwicklung mit Java.

• Einsatz von künstlicher Intelligenz für die Beratung und Entwicklung sowie im Rahmen der Kundenlösung.

• Fundierte Erfahrung in der Anwendung von Best Practices für Codequalität, Tests und Performance-Optimierung im agilen Kontext.

• Tiefgehende Kenntnisse in Software-Architekturen.

• Grundkenntnisse in Infrastrukturtechnologien (Docker, Kubernetes, Cloud-Services, CI/CD).

Benefits

• Faire Bezahlung.

• Remote Work / Home-Office Ausstattung.

• Trainings & Coachings.

• Moderne/ergonomische Arbeitsmittel (z.B. von Apple).

• Gesundheitsförderung (z.B. Fitnessnetzwerk).

• Eine wertvolle Kultur mit Freiräumen, Mitgestaltung & Wertschätzung.