---
title: 'Senior Backend Engineer - Kotlin (m/f/d) - Agent SDK at voize'
canonical: 'https://feeny.ai/job/senior-backend-engineer-kotlin-m-f-d-agent-sdk-voize-berlin-nzjc1q7p07ta'
type: 'job'
last_seen: '2026-09-07'
---

# Senior Backend Engineer - Kotlin (m/f/d) - Agent SDK at voize

- **Company:** voize
- **Location:** Berlin, Germany
- **Employment:** full-time
- **Work type:** remote
- **Posted:** 2026-09-07
- **Last confirmed live:** 2026-09-07
- **Apply:** https://jobs.ashbyhq.com/voize/f8208ddb-f30f-4687-b8ac-f9d84f17d9c3

## Job description

🎤 Why voize? Because we're more than just a job!

At voize, we believe the greatest gift to frontline workers is time - time to care, connect, and be present. Today, that time is lost to busywork and complex systems that pull them away from what matters most: people.

Our vision is to change that by building AI companions that seamlessly take over digital workflows. We don't replace humans with technology - we amplify their impact.

Our mission is backed with a $50M Series A funding led by Balderton Capital, with support from HV Capital, Y Combinator and other leading VCs. Today, 2,000+ facilities trust voize, and over 200,000 users rely on our AI companion to ease their daily workload.

As a dynamic team, we combine first-in-class technology with meaningful social impact. And now, we're looking for you to join us on this mission!

💡 Your Mission: Build the layer every agent moves onto

As Senior Backend Engineer on the team behind our Agent SDK, you build and maintain the Kotlin foundation that our AI agents move onto. Agents have grown into a product surface across verticals and markets, and the layer underneath them needs a permanent owner. Your work makes the cost of the second and third agents visibly less than the first, so feature teams can ship at their own pace.

🚀 Your Daily Business - No two days are alike

- Build and maintain the SDK as an internal product. You shape the runtime and the client-facing contracts that consuming teams build on. The SDK has a roadmap of its own, and you help set it.
- You build the identity layer that agents run on, so customer-facing agents can write with a real user identity. Your responsibilities may include designing and shipping the auth plumbing, depending on what we have already built by your start date.
- Make every agent observable from the day it launches. You wire telemetry and error reporting into the SDK by default, and you integrate inference and anonymization so the SDK enforces them for every consumer.
- Build the test kit that the SDK still needs. You create it along with the architecture tests that protect the runtime internals, and you build the path that runs every SDK agent against our ML team's evaluation harness before a model change ships.
- Absorb ecosystem change on behalf of consuming teams. You own Koog version bumps and format compatibility, and you set the shared limits on tool output and token usage, so an upgrade lands once in the SDK and reaches everyone from there.

🤝 Your Skillset - What you bring to the table

- Several years building production backend systems in Kotlin, including something other engineers consume. An SDK or an internal platform where the contract you publish is the product, and where you have lived with the versioning work that follows.
- Testing and observability are part of how you build. You have set up the tooling that makes a codebase comfortable for other people to work in.
- You are drawn to AI agent systems, and to the orchestration and evaluation work underneath them. Whether from work or your own projects, you are close enough to the space to know where it gets hard.
- You bring teams with you. Much of this work reaches squads across engineering, so you gather what consumers need and make your reasoning easy to follow. You communicate clearly in English.

🌱 Growing together - what you can expect at voize

- We are a fast-growing startup, that means you will take on real problems, grow quickly, and make a real impact, giving frontline workers more time for people
- We foster an open, collaborative culture with regular team events, whether you work from our Berlin office or remotely across Germany
- Become a co-creator of our success with stock options
- Generous perks: 30 vacation days plus your birthday off, Germany Transport Ticket, Urban Sports Club, regular company off-sites, and access to learning platforms such as Blinkist and Audible, plus free language courses
- You decide when you work best, that means flexible working hours and a good hybrid set-up.

✨ Ready to talk? Apply now! 🚀

We look forward to your application and can't wait to meet you - no matter who you are or what background you have!

## About voize

## Company Overview
- **One-liner**: voize builds an AI companion for nurses that converts spoken notes into structured documentation, synced in real time to Electronic Health Records (EHRs), giving caregivers back up to 30% of their time per shift.
- **Entity Type**: Private (funded: Series A, Winter 2022 Y Combinator batch)
- **Headquarters**: Berlin, Germany
- **Founded**: 2020
- **Founders**: Fabio Schmidberger (CEO), Marcel Schmidberger (COO), Erik Ziegler (CTO)

## Core Business
- **Primary industry/industries**: Healthcare IT, AI-powered clinical documentation, skilled nursing and elder care
- **Target customers**: B2B – skilled nursing facilities, long-term care homes, and other healthcare providers employing frontline nurses
- **Mission or purpose statement**: “Give time back to those who care” – eliminate administrative burden so nurses can focus on people, not paperwork.

## Products & Services
- **[AI Companion for Nurses]**: A voice-based AI solution that runs locally on smartphones (no constant internet connection required). It listens as nurses speak during care, automatically structures and categorizes notes, and syncs them in real time to existing EHR systems. Designed for point-of-care documentation with offline capabilities.

## Market Standing
- **Valuation/Market Cap**: Not publicly disclosed
- **Key Metric**: Total funding – $50M Series A (announced November 2025)
- **Notable Investors/Partners**: Balderton Capital (lead), HV Capital, Redalpine, Y Combinator (Winter 2022). Primary YC Partner: Nicolas Dessaigne.
- **Growth Signals**: 180,000+ nurses use voize; 1,100+ care facilities in Germany and Austria; 200M+ documented entries; 27% reduction in documentation time per shift; 9% more time on patient care; 15% reduction in staff turnover; care homes feature voize in job ads to attract nurses. The company is expanding into the US market.

## Competitive Advantages
- **Purpose-built for nursing** – developed in-house over tens of thousands of hours in care homes, not a generic AI repurposed for healthcare.
- **Offline-first architecture** – runs locally on smartphones, ensuring high data protection and continuous operation even when Wi-Fi fails, a first in healthcare AI.
- **Language & dialect support** – understands complex medical language, regional dialects, and non-native speakers, empowering diverse care teams.
- **Deep EHR integration** – bi-directional sync with all major EHRs for skilled nursing and long-term care, fitting naturally into existing workflows.

## Strategic Focus
- **European expansion and US market entry** – the $50M Series A will accelerate geographic growth and product development.
- **Expanding beyond documentation** – the AI companion will eventually cover all administrative workflows for frontline workers, starting with nursing.
- **Deepening integration with care facilities** – proven impact on nurse satisfaction and retention makes voize a tool that helps facilities attract and retain staff.

## Why Work Here
- **Culture & values**: Humans First, Aim for Epic, Act with Urgency, Care Always, Own the Outcome, Turn Complexity into Clarity. Emphasis on cross-functional collaboration, empathy, and making a real difference in healthcare.
- **Work policy**: Flexible work arrangements and remote-friendly policies – work from the Berlin office or from home, with the option to work from different EU countries.
- **Perks**: 30 vacation days + birthday off, Urban Sports Club membership, and a team that prioritizes connection and celebration alongside meaningful work.
- **Engineering culture**: “We make the complex simple” – the engineering team works on cutting-edge AI models, speech recognition, and offline mobile tech. High autonomy, iterative experimentation, and focus on results.

## Sources
1. [voize.ai – About](https://www.voize.ai/us/about)
2. [voize.ai – Careers](https://www.voize.ai/us/careers)
3. [voize.ai – Product](https://www.voize.ai/us)
4. [Y Combinator – voize](https://www.ycombinator.com/companies/voize)
5. [Tech.eu – voize lands $50M](https://tech.eu/2025/11/17/voize-lands-50m-to-bring-ai-where-its-needed-most-the-nursing-frontline/)

## Other roles at voize

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- [Technical Account Manager - US](https://feeny.ai/job/technical-account-manager-us-voize-new-york-wac94px6hhc9) — New York, NY
- [Senior DevOps Engineer (m/f/d) - healthcare AI](https://feeny.ai/job/senior-devops-engineer-m-f-d-healthcare-ai-voize-berlin-x9210nvrd6jh) — Berlin, Germany
- [Sales Development Representative (m/f/d) - SaaS](https://feeny.ai/job/sales-development-representative-m-f-d-saas-voize-berlin-x1fzqhayb1ze) — Berlin, Germany
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- [Growth Marketing Manager (f/m/d)](https://feeny.ai/job/growth-marketing-manager-f-m-d-voize-berlin-394n46303zcv) — Berlin, Germany
- [Engineering Manager (m/f/d)](https://feeny.ai/job/engineering-manager-m-f-d-voize-berlin-5cybwrr8jgc9) — Berlin, Germany
- [Senior Community Manager - B2B (m/f/d)](https://feeny.ai/job/senior-community-manager-b2b-m-f-d-voize-berlin-s00tc8j1ahnf) — Berlin, Germany
- [Revenue Operations Manager (m/f/d) - Sales Ops & Strategy](https://feeny.ai/job/revenue-operations-manager-m-f-d-sales-ops-strategy-voize-berlin-w5n952hm350a) — Berlin, Germany