freelance English-speaking jobs in Bonn

Senior Software Engineer will build end-to-end solutions for the post-purchase experience. Responsibilities include designing and implementing scalable systems, shipping high-quality code, and collaborating cross-functionally. Technical skills required include experience building production software across multiple layers of the stack, proficiency in at least one modern language/framework, and experience with SQL and NoSQL databases.

Tenure track group leader position in experimental freshwater ecology. Develop and lead a research group focused on the impacts of global change on freshwater ecosystem functioning, community composition, and food-web structure. Strong expertise in experimental design and aquatic community ecology required.

Tester Work seeks QA testers and tech enthusiasts in Germany for project-based opportunities. Perform test case executions, functional exploratory tests, and usability tests. Payments are made via PayPal, Wise, or Upwork within two weeks of project completion.

This 6-month full-time internship focuses on Advanced Analytics for Risk, Fraud & Banking Innovations. The Associate System Engineer Intern will collaborate with sales and advisory teams, explore innovative applications of SAS analytics in banking, and assist in creating proof of concepts.

Full-stack engineer with a backend focus needed to build and maintain a user-friendly platform. Responsibilities include developing backend systems, collaborating on product features, and contributing to architectural decisions. Experience with React, Node.js, SQL databases, and CI/CD pipelines is required.

Account Executive drives new business development through cold calling, emailing, and LinkedIn outreach. Responsibilities include executing outbound sales campaigns, qualifying leads, and collaborating with founders on pipeline development. Requires proven B2B sales experience, fluency in German and English, and comfort with autonomous work in a fast-paced environment.

Endowed professorship for Metrology and new measurement methods for quantitative cell analysis at Charité - Universitätsmedizin Berlin and the Physikalisch-Technische Bundesanstalt (PTB). The position is a joint appointment according to the Jülich model with a limited employment status under private law in full-time. The professorship is linked to the management of the research area «Metrology and New Measurement Methods for Quantitative Cell Analytics» at PTB. The focus lies on developing new reference measurement methods to assess infection risks posed by emerging viruses and bacteria using advanced technologies such as optical imaging, flow cytometry, and artificial intelligence (AI).

Software Development Engineer to design, develop, and deploy scalable distributed services for a new Generative AI application. Will translate business requirements into deliverables, build prototypes, and mentor junior engineers. Experience with Java, Python, and AWS required.

Leads Omio's strategic partnerships with large travel and industry players, driving over 10% of Group Revenue. Identifies, negotiates, and executes large partnerships, ensuring long-term value through collaboration and innovation.

Research Assistant (Doctoral student) position at the University of Wuppertal. Develop novel machine learning methods for modeling molecular properties within a project focused on exciton transfer in cryptophyte antenna complexes. Collaboration with an international team is required.

Own the rollout of 6 AI-powered inspection hubs across Germany, starting in NRW. Responsibilities include scouting locations, negotiating leases, converting spaces into tech-enabled hubs, and integrating acquired centers into the operating platform. Must be fluent in German (C2), hold a valid Class B driving license, and have a Bachelor's/Master's degree from a top university.

Senior Software Engineer to join the EO team, building core platform capabilities for Personio's HR platform. Focus on backend systems, APIs, and workflows, with occasional front-end contributions. Strong experience as a backend engineer and comfort in ambiguous environments are required.

Because as a global bank we touch the lives of millions of people and strive to have a positive impact on our society and planet. And thanks to our start-up mentality, we stay down-to-earth, approachable and personal – an unbanky bank.

Team Lead Assembly to plan, coordinate, and oversee daily assembly operations, ensuring safety, quality, and productivity. Develop, implement, and optimize processes to improve production efficiency. Collaborate with cross-functional departments and team leaders.

As a (Senior) Integration Engineer, you will design and implement technical solutions for clients, bridging software development and practical application. You will develop custom extensions, integration scripts, and technical documentation, while collaborating with clients and solving complex technical issues.

Senior commercial leader to drive growth for digital pathology portfolio across Europe. Leads and mentors a team, manages sales funnel, and builds key account relationships. Requires 5+ years of experience in healthcare technology sales, digital pathology expertise, and proven success in complex sales cycles.

The Data Center Engineering Operations Technician is responsible for the delivery of best practice systems and problem resolution for data center electrical and mechanical infrastructure. The role requires a self-managed individual who proactively seeks solutions to complex technical problems. Responsibilities include setting and maintaining safety standards, driving continuous improvement efforts, and collaborating with stakeholders to deliver operational excellence. The technician will also be responsible for preventive maintenance, facility monitoring, and responding to potential customer-impacting events.

Procurement Officer supports the effective and consistent delivery of procurement processes. Ensures value for money throughout the procurement to payment process. Manages travel bookings, purchase processes, and payment processing.

Leads the end-to-end real estate lifecycle, including acquisitions, due diligence, and risk assessments. Oversees property-related CAPEX planning, ROI assessments, and lifecycle cost optimization. Develops scalable facility management concepts and manages global facility services and contracts. Conducts workplace audits, manages project reporting, and enforces cost and performance controls. Leads global sustainability and energy management initiatives and oversees global Health & Safety governance. Develops and implements facility management policies and procedures. Collaborates with internal and external stakeholders to ensure high-quality facility management services. Provides leadership and guidance to facility management teams.

Development Engineer (m/w/d) responsible for the entire product lifecycle, from ideation to marketing. Develops new product ideas, implements prototypes, and participates in production structure development. Requires a completed engineering or natural science degree, several years of relevant experience, and strong CAD skills.