Senior Java Developer (f/m/d)

Optimax Energy

EINLEITUNG ÜBER UNS Bei Optimax Energy entwickeln wir seit über 10 Jahren smarte Lösungen für automatisierte Handelssysteme und fördern den Übergang zu grüner Energie. Damit sind wir führend im internationalen Stromhandel. Unser kulturell vielfältiges Team teilt eine gemeinsame Vision und pflegt eine Kultur der Wertschätzung und Chancengleichheit. Wir glauben, dass wir Außergewöhnliches erreichen können, wenn wir uns frei entfalten. Daher legen wir großen Wert auf eine gesunde Work-Life-Balance und fördern kreative Freiräume. Wir leben Vielfalt, Gleichberechtigung und Inklusion. Unterschiedliche Perspektiven und Hintergründe stärken unser Team und führen zu kreativen Lösungen. Dafür schaffen wir eine wertschätzende Arbeitsumgebung, die die Einzigartigkeit aller Mitarbeitenden anerkennt und Talente langfristig bindet. Um die Zukunft der Energiebranche aktiv mitzugestalten, suchen wir herausragende, engagierte Persönlichkeiten, die unsere Vision und Unternehmenskultur teilen. DEINE AUFGABEN Unser Integrators-Team baut die Pipelines und Echtzeit-Monitoring-Systeme hinter dem algorithmischen Energiehandel von Optimax. Wir entwickeln Integrationen mit nationalen Übertragungsnetzbetreibern und öffnen damit den Zugang zu neuen Märkten – was du baust, entscheidet mit, wo Optimax handelt.   Als Java Developer in diesem Team sorgst du dafür, dass unsere bestehenden Services zuverlässig laufen – und entwickelst sie aktiv weiter. * Du erhebst und schärfst Anforderungen in direkter Zusammenarbeit mit Stakeholdern. * Du entwickelst neue Features für die Trading-Plattform. * Du schreibst Unit- und Integrationstests und stellst eine hohe Testabdeckung sicher. * Du betreust die Services, die essenzielle Marktdaten für Handelsentscheidungen liefern – von der Wartung über Troubleshooting bis zur Sicherstellung von Zuverlässigkeit und Skalierbarkeit. * Du führst Code Reviews durch und stellst gemeinsam mit dem Team eine hohe Codequalität sicher. * Du erstellst technische Dokumentation. SO SIEHT ES BEI UNS AUS: Wir arbeiten mit dem folgenden Tech-Stack: * Java, Spring Boot, MySQL, ClickHouse, Kafka, RabbitMQ.  * Integrations: HTTP, AMQP, WebSockets, R Sockets, STOMP und E-Mail; mit JSON, CSV, XML, EDI und weiteren Formaten.  * CI/CD: GitLab, Maven, Jenkins, TestContainers, SonarQube, Portainer und Kubernetes.  * Monitoring: Micrometer, Grafana, Graylog. DEIN PROFIL Must-Haves * Mindestens 5 Jahre Berufserfahrung in der Softwareentwicklung, davon 3+ Jahre in Java (Senior-Level). * Studienabschluss in Informatik oder vergleichbaren Studienfächern. * Fundiertes Verständnis von Object-Oriented Design Patterns und CLEAN-Code-Prinzipien. * Erfahrung im Umgang mit Threads, Java Executors, Concurrency-Modellen und asynchroner Programmierung. * Praktische Erfahrung in der Implementierung effizienter Datenstrukturen und Datenverarbeitung. * Praktische Erfahrung mit Unit- und Integrationstests. * Gute Kommunikationsfähigkeiten in Englisch (Mindestens B2). * Wohnsitz in Deutschland und gültige Arbeitserlaubnis. Nice-to-Haves  * Erfahrung im im Build- und Dependency-Management von Java-Projekten mit Maven. * Erfahrung mit Docker, Jenkins und CI/CD-Pipelines. * Erfahrung im Design und Anbindung von API-Services. * Erfahrung mit Message Brokern und asynchronem Messaging (z. B. RabbitMQ, Apache Kafka). * Erfahrung im Umgang mit dem Spring Framework (Boot, Web, Messaging, Security). * Erfahrung mit agilen Methoden (Scrum, Kanban). * Grundlegende SQL-Kenntnisse für Abfragen und Verständnis relationaler Datenbanken. * Performance Tuning, Profiling und Optimierung. * Verständnis gängiger Software-Architekturnotationen und -standards (UML, C4). * Kenntnisse im Bereich Energiemarkt oder Trading. WIR BIETEN SO ARBEITEN WIR: Wir sind ein Office-first-Team, weil wir gemeinsam vor Ort besser arbeiten. In unserem Leipziger Büro entstehen Ideen im Vorbeigehen, Probleme werden am Whiteboard gelöst und zwischendurch messen wir uns bei einem kurzen Tischtennismatch. Hybrides Arbeiten gehört für uns dazu: in der Regel ein Tag pro Woche im Homeoffice, mit Flexibilität nach Absprache im Team.  Für diese Stelle suchen wir jemanden, der bereits in Deutschland lebt und über eine gültige Arbeitserlaubnis verfügt. Gehalt: 65.000 – 75.000 € brutto/Jahr — abhängig von deiner Erfahrung. Gesundheit & Wohlbefinden: * Täglich frisch gekochtes Mittagessen * Massagen im Büro * EGYM Wellpass * Sport- und Mobilitätsangebote, wie Zuschüsse für ein neues Fahrrad oder Bike Leasing * Betriebliche Krankenversicherung, die Zugang zu zusätzlichen Gesundheitsleistungen bietet Flexible Arbeitsgestaltung und Vergünstigungen: * 30 Tage bezahlter Urlaub * Flexibilität in den Arbeitszeiten je nach Anforderungen der Position * Zusätzlicher Urlaub für die Flitterwochen * Zuschüsse für Kinderbetreuung Teamkultur und Arbeitsatmosphäre: * Regelmäßige Teamevents (Game Night, Tischtennisturnier, Ausflüge, etc.) * Arbeit in einem missionsorientierten, internationalen Team, das Vielfalt und Gleichberechtigung schätzt * Arbeitsatmosphäre mit offenen Türen und flachen Hierarchien * modernes, grünes Büro im Herzen von Leipzig Berufliche Entwicklung und Weiterbildung: * Selbstständigkeit und Verantwortung in der Projektbearbeitung * 10% der wöchentlichen Arbeitszeit für persönliche und professionelle Weiterentwicklung Haben wir Dich überzeugt?  Dann sende uns bitte folgende Bewerbungsunterlagen: * Lebenslauf * Universitäts-Zeugnisse (bei relevantem Studienabschluss in den letzten 5 Jahren) * Relevante Arbeitszeugnisse, Zertifikate (optional) ÜBER UNSEREN BEWERBUNGSPROZESS  Wir nehmen uns bewusst viel Zeit, für unser Kennenlernen. Unseren Bewerbungsprozess im Detail findest Du HIER - schau gern mal rein.

ZEAL Network

ZEAL Network SE is a dynamic, international group of companies that has been creating exciting and innovative lottery experiences for over 20 years. As Germany’s largest provider of online lotteries through our brands LOTTO24 and Tipp24, and a trusted partner of Spain’s ONCE, the second-largest national lottery, we’re shaping the future of the lottery industry. We are passionate about driving innovation, as demonstrated by our newest brands, Freiheit+ and Traumhausverlosung, which bring fresh and exciting dreams to life. Additionally, through ZEAL Ventures, we invest in inspiring e-commerce start-ups like Omaze and DAYMADE, fueling fresh ideas and opportunities. We are looking for a (Senior) Full Stack Next.js Developer (f/m/d) to join our team and contribute to building scalable workflows, integrating backend services and defining reusable frontend patterns for a platform used by internal colleagues across multiple markets and business domains. With direct access to users, you will help shape practical solutions together with Product and UX. YOUR TASKS: * Shape and build a modern Next.js application from scratch, creating the technical foundation for a scalable internal platform * Take ownership of frontend topics and drive technical decisions * Work closely with product, design and backend teams in a lean, agile environment * Integrate and evolve RESTful APIs in collaboration with backend engineers * Ensure high-quality implementation of UI/UX designs with a strong focus on performance and scalability * Write and maintain tests to ensure reliability, security and performance * Contribute to deployment, monitoring and overall application stability together with DevOps * Identify and drive improvements in performance, user experience and conversion * Measure, analyze and iterate on product features based on data WHAT YOU OFFER US: * Strong experience as a Senior Full Stack or Frontend Engineer with a focus on modern web technologies * Deep expertise in JavaScript, React and Next.js (App Router, Server Components, Server Functions) * Proficiency in TypeScript, HTML5 and CSS3 * Hands-on experience with tools such as Tailwind CSS, React Hook Form, TanStack Query, Zod, Shadcn/UI or similar (Tailwind CSS is a must have, everything else nice to have) * Ability to write clean, maintainable and performant code and design scalable architectures * Solid experience integrating and working with REST APIs * Experience with testing strategies for frontend applications (nice to have) * Interest in using modern development tools, including AI-assisted workflows, to improve productivity and quality (nice to have) WHAT WE OFFER * State-of-the-art technologies and an agile environment (Check our Tech Radar: https://lotto24.github.io/tech-radar/) * A modern, dynamic culture grounded in the success of a leading-edge e-commerce company. * A talented team of ambitious, like-minded colleagues where your knowledge and ideas truly make an impact. * Ongoing personal growth, supported by an annual development budget of €1,500 to invest in your professional development. * Trust and autonomy, no micromanagement, just confidence in your ability to deliver and excel. * Flexible work options with a hybrid setup focused on results. * Unlimited vacation days in addition to your yearly 30-day vacation allowance. * Opportunity for workations abroad using our WorkFlex tool. * Monthly mobility allowance of €30 to use on the mobility option of your choice (e.g., the Deutschlandticket), plus access to a company bike leasing program. * Company pension scheme, provided in partnership with Degura, to support your future financial security. * Subsidized EGYM WELLPASS membership, with a contribution of only €25 per month, giving you access to a wide range of gyms and sports options across Germany. * Monthly company events, team activities, and informal gatherings, including our popular company-wide lunches provided four days a week. Not ticking every box or think you’ve got that unique set of skills we haven’t realized we need? Get in touch anyway, we’re always looking to add great people!

Awin

PURPOSE OF POSITION Awin's Product Development department is responsible for all stages of the product lifecycle - from ideation to market release, ongoing operation and continuous improvement. Working within one of our agile Engineering teams, this role reports to an Engineering Manager. As a Senior Software Engineer, you will be a technical leader within the team - driving architectural decisions, owning complex technical initiatives, and raising the engineering bar across the team and beyond. As a Senior Software Engineer, writing SOLID, secure & well-tested code is a given. You bring deep commercial experience across your technical stack and a strong understanding of infrastructure, platform engineering and cloud-native patterns. You are comfortable navigating ambiguity, making pragmatic trade-offs, and communicating technical direction to both engineers and stakeholders. You are a passionate and innovative technologist with a proactive, quality-first approach to development and keen to gain exposure to the latest development practices and toolsets within an interactive and fun development environment. We value fresh perspectives, continuous personal growth, diversity and a healthy work-life balance. For example: we have a 4-day week at full salary. The Core Team is a platform team in the Developer Platform domain. Its mission is to provide central services around our core entities and systems that make it easier for Product Teams to build functionality on top of. The team provides these "as a service" through clear APIs, documentation and support - focusing on creating a smooth developer experience for other teams. The team also focuses on topics like standardisation, re-use and reducing duplicated effort across the department. As a Senior Engineer in this team, you will play a key role in shaping the platform's infrastructure direction - including API gateways, load balancers, authentication flows, and container orchestration - ensuring our platform is reliable, secure and scalable. AS A SENIOR SOFTWARE ENGINEER, YOU WILL: * Drive technical design and architectural decisions for platform services and infrastructure * Own and deliver complex technical initiatives from concept to production * Work in a small agile team, contributing to planning, reviews and retrospectives * Design, build and improve applications with a focus on infrastructure, reliability and developer experience * Mentor and support fellow engineers * Collaborate with other teams to define API contracts and drive adoption of platform services * Work with Product Managers and the Engineering Manager to shape the technical roadmap * Troubleshoot and resolve complex production issues; participate in on-call rotations TO BE SUCCESSFUL YOU WILL NEED TO MEET THE BELOW REQUIREMENTS: * 5+ years of commercial Software Engineering experience * Strong experience with Java, Maven/Gradle, RESTful APIs, and thorough testing practices * Solid experience with AWS cloud services and infrastructure (ECS, Fargate, ALB, API Gateway, Lambda, DynamoDB) * Hands-on experience with Infrastructure as Code, specifically Terraform * Experience with containerisation and orchestration (Docker, ECS/Fargate) * Understanding of networking concepts: load balancing, API gateways, DNS, TLS/SSL * Understanding of user and client authentication and authorisation flows (OAuth2, OIDC, JWT) * Proven ability to lead technical discussions, make architectural decisions and drive them to completion * Comfortable with on-call responsibilities and incident response * Proficient in using AI-assisted development tools (e.g., Cursor, Claude Code, GitHub Copilot) to accelerate delivery and improve productivity ALTHOUGH NOT REQUIRED, WE WOULD BE EXCITED IF YOU HAD EXPERIENCE WITH SOME OF THE BELOW: * Service mesh concepts and technologies * Observability and monitoring (CloudWatch, distributed tracing, structured logging) * CI/CD pipeline design and optimisation Our Offer * Flexi-Week and Work-Life Balance: We prioritise your mental health and wellbeing, offering you a flexible four-day Flexi-Week at full pay and with no reduction to your annual holiday allowance. We also offer a variety of different paid special leaves. * Remote Working Allowance: You will receive a monthly allowance to cover part of your running costs. In addition, we will support you in setting up your remote workspace appropriately. * Flexi-Office: We offer an international culture and flexibility through our Flexi-Office and hybrid/remote work possibilities to work across Awin regions * Meal Vouchers: You will be supported with a certain net sum to spend it on a variety of lunches. * Health & Wellbeing: The insurance covers several types of health, vision and / or dental treatments for you and for up to one additional family member. * Remote Working Furniture Package: After 3 months of employment, you will be eligible for a furniture package, which should enable you to set up a proper workplace at your remote working location * Appreciation: Thank and reward colleagues by sending them a voucher through our peer-to-peer program. Established in 2000, Awin is proud of our dynamic, social and inclusive culture. Like all businesses, we’ve had to adapt and nurture our culture in a virtual environment. Our virtual ‘Life @ Awin’ hub brings our colleagues from across the globe together for various social activities. Diversity & Inclusion are paramount to us, and we proudly pursue and hire diverse team members. We champion uniqueness and authenticity; this is who we are at our core. Our network of affiliate partnerships are diverse and transparent, as are the employees powering our vision to build the world’s leading open partner ecosystem. We welcome all backgrounds, identities, and experiences. If you need support at any point in the application or interview process, please let us know. Awin is part of the Axel Springer group. Learn more at axelspringer.com/en/, and explore the Axel Springer Essentials here: axelspringer.com/en/inside/the-essentials-what-we-have-adapted-and-why   Apply now to begin the next stage of your career at a progressive company that supports both your professional and personal development. #LI-RS1