Fonio.ai is an advanced AI-powered phone communication platform built to transform how businesses manage customer calls. Its intelligent, human-like voice assistants operate 24/7, handling complex workflows such as appointment booking, lead qualification, and customer support—without the need for human intervention. Powered by state-of-the-art natural language processing, Fonio.ai delivers natural, professional conversations, freeing teams from repetitive administrative work so they can focus on higher-impact tasks. 

Fonio.ai integrates seamlessly into existing business systems, connecting with CRMs such as HubSpot and Salesforce, calendars, and tools like Slack. Calls are automatically transcribed and synchronized in real time. Headquartered in Vienna with infrastructure hosted in Germany, the company adheres to GDPR requirements and strict European data protection standards. From small clinics to large enterprises, Fonio.ai offers a scalable, cost-efficient solution that ensures every customer call is answered.  

Over the past 12 months, Fonio has grown into the leading AI phone solution provider in the DACH region. The company is now scaling across Europe to redefine how small and medium-sized businesses communicate. 

As a Founding Product Engineer, you will take full ownership of features end-to-end—from initial concept and prototyping to production-ready solutions used by thousands of businesses across Europe.  

Key Responsibilities 

• Build and enhance Fonio’s platform using NestJS and React
  
  
• Work closely with customers through support, feedback sessions, and user testing
  
  
• Over time, take ownership of feature and opportunity prioritization for Fonio’s Voice AI product
  
  

What We Offer
 

• 100% remote work, with access to a modern office in Vienna’s 7th district if you’d like to work on-site occasionally
  
  
• Deep focus time with no regular recurring meetings
  
  
• High execution speed, with frequent product releases
  
  
• The opportunity to build a product alongside thousands of engaged customers who actively shape its development
  
  

Your Profile
 

• Strong growth mindset and product-driven thinking
  
  
• Extensive experience with TypeScript, React, and Node.js (NestJS preferred) in a SaaS environment
  
  
• Pragmatic approach to product development: breaking down features into high-impact essentials and iterating based on real user insights
  
  
• Hands-on experience working directly with customers (support, user research, feedback sessions)
  
  
• Native-level German proficiency to actively help shape and train the AI voice experience
  
  

Hiring Process
 

• Introductory screening call – 20 minutes
  
  
• Technical interview – 60–90 minutes, including a coding challenge
  
  
• Culture fit interview – 60 minutes focused on collaboration style and expectations