(Freelance) Senior Backend Engineer (m/f/d) - Agent SDK

Description: Join voize as a Senior Backend Engineer to build and maintain the Kotlin foundation for AI agents. Shape the SDK as an internal product, ensuring it meets the needs of consuming teams and enhances agent functionality. Requirements: Several years of production backend experience on the JVM (Kotlin, Java, Scala, etc.). Experience designing APIs for other engineers to build against, particularly in SDK or internal platform contexts. Proven ability to build and maintain integrations, ensuring stability amid changes. Strong focus on testing and observability in development. Interest in AI agent systems and related orchestration and evaluation work. Benefits: Opportunity to make a real impact in a fast-growing startup environment. Open, collaborative culture with regular team events and flexible working hours. Stock options as part of the compensation package. Generous perks including 30 vacation days, birthday off, transport ticket, sports club access, and learning platforms. Hybrid work setup allowing you to choose your best working hours.