Job Board

About LeydenJar

At LeydenJar Technologies, we’re on a mission to redefine the future of energy storage. Our goal is to become the world’s innovation leader in advanced battery anodes, empowering the next generation of batteries that drive progress.

Why does this matter? Because the world needs higher energy density batteries not just for better consumer electronics, but for electric vehicles, e-flight, and beyond. While the battery industry typically advances by only 3% per year, our breakthrough pure silicon anode technology delivers an improvement of up to 70%, a true game changer. Often called the “holy grail” of the battery industry, our technology unlocks new possibilities for electrification, sustainability, and resilience in global supply chains.

What we do:

• We produce pure silicon anode rolls that fit seamlessly into existing battery cell manufacturing lines, enabling customers to make a quantum leap in performance or create entirely new product categories.

• Our initial focus is on consumer electronics, with automotive applications already in development.

• By leveraging semiconductor thin-film technology (plasma deposition) and scaling it to battery anodes, we’ve overcome the long-standing challenges of silicon in batteries, delivering durability and efficiency at scale.

To meet global demand, we’re scaling up:

• PlantOne in Eindhoven opens in 2026-2027, producing anode rolls and validating our roll-to-roll production tools.

• PlantTwo, our large-scale production facility, will follow, establishing LeydenJar as a key player in the global battery market.

This is an enormous opportunity and an ambitious journey. It requires bold, creative, and diverse minds who share our passion for innovation and sustainability. At LeydenJar, we value different perspectives, inclusive collaboration, and gender equality because we know that diversity fuels breakthrough ideas.

We are looking for a temporary HR Officer to support our team for a period of 7 months. In this role, you will be responsible for managing day-to-day HR operations and supporting the HR Manager across a wide range of activities. You will play a key role in facilitating recruitment, onboarding, and the performance management cycle, ensuring a smooth and positive employee experience. This is a great opportunity to gain valuable, hands-on experience within a fast-growing, international scale-up environment where no two days are ever the same.

In your role you will be:

1. Daily HR Operations and Employee Administration:

• Assist in daily HR operations and employee administration tasks.

• Provide administrative support on performance management inflow and outflow.

2. Recruitment and Selection:

• Partner with Heads of Departments to facilitate recruitment.

• Review the Applicant Tracking System daily to find high-quality candidates.

• Implement recruitment, selection, and guidance of employees.

• Provide vacancy texts, manage, and update them on various channels.

• Select candidates, organize interviews with managers, and participate as needed.

• Act as a point of contact during recruitment and selection procedures.

• Draw up individual standard employment contracts.

3. On-boarding and Off-boarding:

• Coordinate and provide support for new hire on-boarding and relocation, if needed.

• Take care of the exit process at the request of the employee, including conducting exit interviews.

4. Absenteeism Management:

• Monitor the implementation of the Gatekeeper Improvement Act and maintain contacts with the Occupational Health and Safety Service.

• Monitor and analyze the organization’s absenteeism figures and propose solutions to the HR Manager.

5. Training and Development:

• Maintain a network of training and education providers and keep up with market developments.

• Select possible training and education providers that match the set learning objectives and present these to the HR Manager.

• Monitor the progress and quality of the offered training courses.

6. Company Culture:

• Promote and support LeydenJar fun initiatives and positive culture.

Who are you?

• A completed education MBO or similar level in HR or related field

• Min 3+ years of experience in an HR support role

• Experience with HR (ATS, payroll) systems is an advantage.

• Excellent communication skills in English, both written and spoken

Competencies:

• Ability to use data to drive enhancements and efficiencies in operations

• Ability to adapt quickly and navigate a changing work environment effectively

• Attention to details

• Excellent listening skills, EQ and empathy.

Why LeydenJar?

• Unleash Your Potential: Step into a workplace where growth and ownership go hand in hand. We empower every individual regardless of background, gender, or identity to thrive and achieve their career aspirations.

• Pension & Insurance Security: We care about your future. LeydenJar contributes 10% on top of your monthly gross salary toward your pension and life insurance, ensuring long-term security for you and your loved ones.

• Recharge & Refresh: Enjoy 25 vacation days per year (based on full-time hours) because work-life balance is essential for everyone.

• Travel Made Easy: We cover your home-to-work travel costs with €0.23 per kilometer or provide an NS Business Card for hassle-free public transportation.

• Continuous Learning: Access our online learning platform (Udemy) to develop your skills and unlock new opportunities for personal and professional growth.

• Diverse, Inclusive & Equal: Be part of an international team of 20+ nationalities, where everyone’s voice matters, and where diversity, equity, and inclusion are more than values they’re actions.

• Community & Connection: From team-building events and monthly lunches to year-end celebrations and inclusive gatherings, we create spaces where everyone feels welcome and engaged.

Do you want to take on the challenge as HR Officer?

We are looking forward to your application!

If you'd like to learn more about LeydenJar amazing team, see below:

At LeydenJar we value diversity, and we provide equal opportunities to all applicants without regard to race, color, ethnicity, religion, gender, pregnancy/childbirth, age, national origin, sexual orientation, disability, etc. If there are two or more applicants of equal suitability for a certain position, LeydenJar can under circumstances decide to select applicants based on positive discrimination in full compliance with all relevant and applicable law.