java English-speaking jobs in Mainz

This fixed-term, part-time (67%) PhD position focuses on electrochemical CO₂ reduction. The successful candidate will design, fabricate, and optimize catalyst-coated electrodes for CO₂ electrolysis, conduct experiments, and analyze data.

Manage a structured sales approach for designated accounts, implement a commercial sales strategy, and provide technical support for plywood applications.

Manages end-to-end production of seasonal assets for e-commerce platforms, including marketing content. Collaborates with creative and production teams to ensure smooth operations and high-quality asset delivery. Develops and implements process improvements, including new scheduling processes and templates. Liaises with stakeholders across Marketing & Consumer, Creative departments, and external partners.

Stranger Soccer seeks a passionate entrepreneur to open and operate their business in Berlin. The License Owner will build and lead a team, secure game venues, and drive sales and marketing to introduce Stranger Soccer as a convenient way to play football.

Lead and mentor a team of developers, driving architectural decisions and coding standards. Design, develop, and maintain scalable web applications, architecting complex systems for reliability and security. Conduct code reviews, develop automated tests, and collaborate with teams to deliver high-quality solutions.

Delivers and picks up packages to residential and commercial properties. Practices safe driving methods and ensures excellent customer service. Must be able to lift up to 70 lbs.

Provides administrative and logistical support to the MTRI team. Responsibilities include organizing marketing activities, managing office supplies, handling correspondence, and planning events. Requires advanced MS Office skills, fluency in English and German, and strong organizational and communication skills.

The Regional Marketing Communications Manager executes Megger's marketing strategy, focusing on event management, channel partner marketing, regional market activation, and reporting.

Develops and manages Cafeyn Premium distribution partnerships across Europe, with a focus on the DACH region. Leads the full sales cycle, from prospecting and pitching to closing deals. Manages executive relationships and collaborates cross-functionally.

Develop software tools for data management within a research environment. Focus on semantic web technologies, data documentation, and user-friendly data collection tools. Collaborate on projects, publish results, and mentor students. Requires a relevant master's degree, programming experience (Java, Python, JavaScript), and backend development expertise.

Senior / Principal HVDC System Design Consultant will develop cutting-edge HVDC transmission solutions. Responsibilities include design and feasibility studies, system and equipment design, system studies and modeling, control and protection strategies, technical negotiations and testing, and reporting. The role requires a university degree in Electrical Engineering (or a related field) and 7+ years of experience in HVDC projects.

Drive sales success in the DACH region by achieving ambitious sales targets and managing the full sales cycle. Engage with clients, present solutions, and secure new partnerships. Collaborate with internal teams to ensure a seamless client onboarding experience.

Field Service Engineer will perform preventive and corrective maintenance, installation, and commissioning of probers. Responsibilities include technical training, troubleshooting, and customer communication. Requires an engineering or technician background with 2-4 years of experience.

Porsche Consulting seeks a (Senior) Consultant to conduct strategic projects for aerospace OEMs and suppliers. Focus areas include product lifecycle optimization, production efficiency, and digitalization.

Validation Engineer will build and operate cloud-based validation environments for a multi-agent AI system. Responsibilities include designing AI-assisted exploration strategies, developing coverage models and metrics, establishing validation methodologies, and building observability tooling.

Accountant (m/f/d) to support the Head Office Team in Northern Europe. Responsibilities include month-end close, travel expense management, financial controls, and collaboration with external providers and advisors. Requires a completed apprenticeship or degree in accounting, experience preparing financial statements, and fluency in German and English.

As a Quant & Engineering Intern, you will develop quantitative analyses, models, and prototypes to solve real trading problems for clients in the energy sector. You will use AI tools and Python for data science and quantitative modeling, and collaborate with traders and the CTO.

Accounts Receivable Accountant supports the Accounting Team in Berlin. Responsibilities include invoicing, processing payments, account reconciliations, and handling payment disputes. Requires commercial training, experience in accounts receivable, strong German and English skills, and proficiency in MS Office and ERP applications.

Area Sales Manager (m/f/d) for Latin America and Brazil. Supports dealers and sales companies with sales, product training, and application consulting. Requires proficiency in English and Spanish, with Portuguese beneficial.

Senior Enterprise Sales Specialist to accelerate growth of the Stibo Systems Customer Experience Data Cloud. Supports and elevates regional sales teams, acting as a trusted advisor to enterprise customers. Leads complex sales cycles, drives deal strategy, and provides coaching to regional teams. Requires 10+ years of enterprise software sales experience with a strong track record selling Customer Data Solutions. Proven success in complex enterprise environments and experience in overlay / specialist sales roles within matrixed, international organizations. English is essential; additional languages are a strong asset.