Senior Software Engineer Voice Full-Stack

Meet DeepL

DeepL is a global AI product and research company focused on building secure, intelligent solutions to complex business problems. Over 200,000 business customers and millions of individuals across 228 global markets today trust DeepL's Language AI platform for human‑like translation, improved writing and real‑time voice translation. Building on a history of innovation, quality and security, DeepL continues to expand its offerings beyond the field of Language, including DeepL Agent – an autonomous AI assistant designed to transform the way businesses and knowledge workers get work done.

Founded in 2017 by CEO Jarek Kutylowski, DeepL now has over 1,000 passionate employees and is supported by world‑renowned investors including Benchmark, IVP, and Index Ventures.

Our goal is to become the global leader in trusted, intelligent AI technology, building products that drive better communication, foster connections, and create a meaningful impact.

What sets us apart is our blend of cutting‑edge AI technology, meaningful work, and a culture where people truly thrive. We’re a team of innovators, researchers, and creators driven by a shared purpose to unlock human potential by making work simpler, smarter, and more connected.

When we share what it’s like to work at DeepL, the reactions are overwhelmingly positive. This might be because of our technology that helps millions of people and businesses communicate and work better every day, or because of the trust, curiosity, and care that shape our culture.

What we know for sure is this: being part of DeepL means joining a team dedicated to innovation, growth, and well‑being. Discover more about life at DeepL on Linked In, Instagram, and our Blog.

You will join DeepL Voice, the team defining the art of the possible for real‑time interpretation. While our Translation engine conquered text, Voice is conquering the physical world. We are building the “Universal Translator” enabling fluid, real‑time conversations for frontline workers, global meetings, and enterprise teams.

This is a 0‑to‑1 engineering environment. We successfully launched our first customer‑facing features in late 2024, but we are just getting started. We are tackling the hardest problems in AI interaction:
How do you eliminate the “flickering” effect of unstable transcripts? How do you chain chunked inference to achieve sub‑millisecond latency? How do you deliver a seamless audio stream that feels natural, not robotic?

You will work in a dynamic, cross‑functional squad alongside Researchers, Product Managers, and Designers. We are not just wrapping an API; we are building the proprietary models, the streaming architecture, and the user interfaces that allow the world to speak without barriers.

• A “0‑to‑1” Builder Mindset:
  You thrive in ambiguity. You don’t need a roadmap to build; you need a problem. You are comfortable prototyping a new feature in the morning and refactoring it for scale in the afternoon.
• Full‑Stack Fluency (with a Backend Tilt):
  You can build a polished UI in React, but you are equally comfortable deep‑diving into C#/.NET Core, WebRTC, or streaming architectures. You understand the complexity of handling state in a real‑time application.
• Product Obsession:
  You care about the flow of the conversation. You understand that “99% accuracy” means nothing if the audio arrives 3 seconds late. You optimize for the human experience.
• High Agency:
  You identify bottlenecks whether in the UI rendering path or the backend inference queue and you fix them. You act as a technical leader, raising the bar for the engineers around you.

• A “Product‑First” Mindset:
  You care deeply about the customer journey. You ask, “How does this feature help us close the next Enterprise deal?” before writing code.
• Full‑Stack Fluency:
  You are comfortable traversing the stack. You can design a React component for an admin dashboard in the morning and debug a distributed transaction in the backend in the afternoon.
• Enterprise Domain Curiosity:
  You are interested in the hard problems of B2B SaaS identity (SAML/SSO),…