what we need! Mend.io is building the next generation of application security for AI-powered software, and Mend AI is the team leading that bet. Our product detects and secures AI/ML components inside applications - addressing emerging risks like prompt injection, data leakage, and adversarial attacks - in a domain where the standards are still being written. We're looking for a Principal Software Engineer to take end-to-end ownership: from research and design through production, on systems that combine classical algorithms with AI/LLM-based capabilities. This is an AI-native role in both senses - you'll build security for AI systems, and you'll work AI-first yourself, using coding agents across the development lifecycle and knowing how to get consistently high-quality results from them. You'll work as a senior individual contributor with real influence over architecture and product direction, collaborating directly with security researchers, data scientists, and product managers across our Poland and Israel teams (1-hour time difference - genuine daily collaboration, not satellite work). What You'll Do Own solutions end to end - from studying the domain and generating your own ideas, through research and design, to coding, shipping, and supporting them in production. Drive independent research in a new domain where problems are not fully defined, balancing innovation with practical, cost-effective engineering Build and evolve backend & frontend, extending traditional microservices with AI/LLM-based capabilities Use AI agents throughout development - research, design, coding, and testing - to raise both speed and quality Work closely with security researchers, data scientists, and product managers to turn ideas into shipped product What We're Looking For 10+ years of backend software engineering experience, including 3+ years in a hands-on technical leadership role (Principal / Tech Lead / Architect) A product mindset: you connect technical decisions to busi
