At telli, we're building the first AI-native phone system.
Since launching last year at Y Combinator (the same investors behind Airbnb, Stripe, Twitch, Coinbase, and others), we've grown >$2M in annualized revenue with a team of only 12 people.
Today, many companies fail in their customer communication not because they don't care, but because they can't keep up. The sheer volume of calls forces to rely on low-quality outsourced call centers or have their internal teams waste hours on repetitive calls.
With telli, our customers now rely on AI voice agents that handle their repetitive calls, freeing human to focus on what matters - talking to customers when it counts. The result: higher efficiency, happier teams, and better customer experiences.
Legacy phone systems weren’t designed for an AI-first world. That is why we are building the first AI-native phone system that lets companies manage both their human and AI teams on one platform.
Our founding team knows this problem inside-out. We ran a 150-person internal call center at Enpal. We know how difficult and expensive it is to scale high-quality customer experience with phone calls.
The opportunity is massive!!! and we're just getting started. We're on a mission to let every company provide a world-class customer experience by ending the era of low-quality call centers.
This is the perfect role for someone with an engineering background (e.g. CS degree, coding bootcamp, or business informatics) who wants to apply their technical skills in a hands-on, customer-facing environment.
AI voice agents are transforming how companies communicate with customers, but integrating them into existing workflows is still complex.
As a Customer Engineer at telli, you’ll sit at the intersection of customer success, support, and engineering. You’ll help our customers design, deploy, and scale AI agents that handle thousands of real customer calls every day.
You’ll become the go-to technical partner for our customers - solving problems, improving performance, and bringing feedback directly to our product and engineering teams.
If you’re technical, communicative, and thrive in fast-moving environments, this role is for you.
what you’ll be responsible for
Customer success from a technical angle: act as the primary technical point of contact for key account customers, from onboarding to scaling
Design and implement AI agents: build, test, and optimize telli agents that handle real customer conversations at scale
Support and debug: investigate customer issues, troubleshoot technical problems, and work with engineering to ship fixes fast
Enable self-service: improve our documentation, prompt templates, and guides so customers can solve problems independently
Help shape our platform: surface customer insights, identify missing features, and collaborate directly with product to improve our tools
Build PoCs, Integrations & Workflows: prototype improvements, create internal workflows, and help build integrations to 3rd party systems
what makes you a great fit
You really enjoy working with customers and help them succeed
You have a good software engineering foundation
you’re an excellent communicator in both English and German (additional languages are a big plus) - especially writing
you’ve built AI agents and understand topics like prompt engineering and evals
you may not make a good fit if…
you can only write code with the help of AI
you have a pure business background but want to transition to tech
you only like ‘strategic’ work and don’t want to get your hands dirty
you don’t understand how web applications & APIs work under the hood
you want to work 9–5
above-market pay & equity
access to any (AI) tool that makes you more productive
gym subscription
regular off-sites with the team
Top Skills
What We Do
AI phone calls that convert
