Executive Assistant (60-80%)

About CellX Biosolutions AG

At CellX Biosolutions, an innovative ETH spin-off, we develop microbial solutions to degrade persistent environmental pollutants such as PFAS, and pesticides. Our mission is to bring the world's first commercial bacterial solution for PFAS remediation from the lab into real-world industrial application.

Role Overview

We are looking for an organised, hands-on person to keep CellX running smoothly behind the scenes. In this 60-80% role reporting to the COO, you will look after our finance, HR administration and our office. You will also organise our team and external events, and support our marketing activities and trade fair presence. As the first point of contact for the team's practical needs, you will help shape how a fast-growing startup works, support the executive team, and make sure our scientists and engineers can focus on bringing our PFAS solutions to market.

Main tasks:

Finance

• Record supplier invoices and expenses in Bexio for our external accountant
• Process supplier payments and employee expense reimbursements
• Client invoicing and follow ups
• Nice to have: Monthly bank reconciliation and support financial reporting for grant projects.

HR

• Coordinate recruitment: publish job ads, pre-screen applications, schedule interviews and keep candidates informed
• Handle administrative onboarding and offboarding of employees
• Manage employee insurances (social insurances, accident, daily sickness allowance) and keep them up to date
• Handle administration of sickness and accident cases with insurers.
• Support relocation of new employees when necessary.

Office management

• Act as first point of contact for the team's practical needs and continuously improve how our office runs
• Order and prepare IT equipment (Computer, screen, keyboard) for new team members and keep inventory
• SaaS and IT license management.
• Maintain stock of office supplies and orders

Event management and culture

• Organise 2–3 internal team events per year (logistics and program)
• Organise the logistics of our yearly event with external stakeholders.
• Propose and organise team-building activities to support our team culture

Marketing & communication

• Create digital and print marketing material (slides, newsletter, flyers, business cards, roll-ups) and handle print orders
• Travel booking and coordination
• Coordinate booth design and logistics for trade fairs
• Support follow-up with prospects after events (contact database, mailings)

Your profile

Required qualifications

• Commercial apprenticeship (Kauffrau/Kaufmann EFZ) or equivalent training, with at least 5 years of professional experience in administration, office management or a similar role
• Hands-on experience with accounting administration: recording invoices, processing payments and expense reimbursements
• Experience with HR administration, including onboarding, social and employee insurances, and handling sickness and accident cases
• Very good command of MS Office or Google Workspace; first experience with design tools (e.g. Canva) for marketing material and open/experience with the use of AI tools (e.g. Claude).
• Proactive, structured and reliable working style, comfortable working independently and juggling several topics at once
• Discretion in handling confidential information (finance, HR)
• Fluent English (C1 or higher) and good German (B2 or higher)

Preferred qualifications

• Further training in accounting (e.g. Sachbearbeiter/in Rechnungswesen) or finance and experience with bank reconciliations
• Experience with Bexio as an accounting software
• Interest in or first experience with financial planning and modelling
• Experience organising events and coordinating logistics with external suppliers
• Experience in a startup or small-company environment

We offer

• A varied role at the heart of a fast-growing ETH spin-off, with real ownership over how our company runs
• The opportunity to build and improve our administrative processes from the ground up
• Flexible organisation of your 60% workload
• A modern workplace in Schlieren, close to Zurich and easy to reach by public transport
• Opportunities for training and professional development
• Competitive salary
• Collaborative startup culture with fast decision-making, and the opportunity to have a significant impact in developing the world's first commercial bacterial solutions for PFAS bioremediation

Start date:

04.01.2027

Work location:

 Wagistrasse 18, 8952 Schlieren

Application Process

We look forward to receiving your application through the form on our website ( www.cellx.ch/careers ) before 25.10.2026.