Welcome to ista

At ista, we support property owners and managers in making their buildings fit for the future and kind to the planet. That includes tracking and billing energy consumption in a way that's easy to grasp, to help save energy and cut CO₂ emissions. With over 6,300 employees in 20 countries, we're committed to making it happen. Join us and help shape tomorrow, secure in the knowledge that you're part of a successful company that also offers you the flexibility of agile working practices.

Everyone is welcome at ista, regardless of age, gender, background, sexual orientation, religion or disabilities. We're proud to be part of a diverse team. Fostering a culture of team spirit and togetherness, we are always there for one another. We set great store by ensuring a healthy work-life balance for our people. Plus, we offer each and every employee the opportunity to pursue further training and personal development.

We are looking for a Manager Enterprise Telephony & Contact Center Engineering to drive the transformation of our telephony and call center landscape across six countries, 40+ locations, and more than 3,000 users. In this role, you will shape our future communications architecture, oversee integrations with customer service systems, and build internal expertise to complement our external partners.

• Design and implement our next-​generation telephony and contact center architecture (UC / VoIP / CCaaS)
• Lead the technical workstream of a multi-​country rollout and modernization program
• Act as the internal technical authority and primary counterpart for external providers (e.g., TATA, NTT)
• Develop monitoring, support processes, and knowledge to build in-house capability
• Optimize call flows, IVR logic, routing, and system integrations (CRM, service platforms)
• Ensure system performance, security, availability, and compliance across all locations

• At least 3 years of experience in enterprise telephony (VoIP, SIP, SBCs, PBX) or contact center platforms (Genesys, NICE, Avaya, Cisco, Amazon Connect, or similar)
• Proven track record in delivering large-​scale telephony / UC transformations
• Hands-on technical and administrative skills combined with architectural thinking
• Experience in managing global telecom /UC vendors and complex integration setups
• Understanding of networking (QoS, WAN, Routing), APIs, reporting and system-​to-​system integrations
• Structured communicator with the ability to manage stakeholders and fluent German and English language skills

Nice to have

• Certifications in UC / telephony platforms or ITIL
• Experience in issue troubleshooting (port conflicts and network disruptions)
• Experience in multi-​country environments and customer service operations
• Familiarity with AI / automation capabilities in modern contact center solutions

• Do the right thing with purpose and a future: Our services save CO₂ and protect the envi­ron­ment – we are working for a sus­tain­a­ble world of tomorrow
• Enjoy many benefits: Look forward to an attractive salary, 30 days' vacation per year and flexible working hours, including the opportunity to work up to 50% of the week on a mobile basis
• Secure good prospects for yourself: We are an inter­na­ti­o­nally suc­cess­ful company with agile working methods and an open corporate culture. Our future course offers you long-term and excellent career options
• Stay curious and develop yourself further: Standing still is not an option for us, which is why we support you in every aspect of your deve­lo­p­ment – a variety of learning oppor­tu­nities awaits you
• Expe­ri­ence a working envi­ron­ment full of trust: We all pull together
• Have fun in a motivated team: Whether it's a barbecue event, inter­na­ti­o­nal soccer cup or ice cream for everyone in summer – we always come up with something new, so stay tuned!