Remote - Principal Software Engineer

Mend.io is an established leader in application security with an AI-native AppSec platform trusted by enterprises worldwide. Mend AI operates like a startup within this stability, having a small, senior team with a greenfield mandate and direct access to decision-makers. The Poland team is a core engineering site where architecture decisions are made by engineers.

• 10+ years of backend software engineering experience
• 3+ years in a hands-on technical leadership role (Principal / Tech Lead / Architect)
• Strong experience building systems from scratch in a product environment
• Hands-on experience with a modern programming language (Go preferred; Java or Python also valuable)
• Ability to quickly adapt to new languages and technologies
• Strong product mindset linking technical decisions to business impact
• Proven ability to own and drive initiatives independently
• Experience integrating AI/LLM capabilities into real-world applications
• Hands-on experience using AI agents through development lifecycle
• Solid understanding of cloud environments and modern development practices (AWS, GCP, Azure)
• Strong communication skills and collaboration with senior stakeholders

Nice to have:

• Hands-on experience developing, tuning, or customizing LLM-based solutions beyond out-of-the-box APIs
• Familiarity with AI security challenges (prompt injection, model leakage, adversarial attacks)
• Experience with machine learning workflows (training, deployment, inference)
• Experience with tools such as LangChain, Hugging Face, or OpenAI SDKs
• Background in application security, cloud security, or DevSecOps

• Own solutions end to end: domain study, research, design, coding, shipping, and production support
• Drive independent research in a domain with partially defined problems, balancing innovation and practical engineering
• Build and evolve backend and frontend systems, extending microservices with AI/LLM capabilities
• Use AI agents throughout development to improve speed and quality
• Collaborate closely with security researchers, data scientists, and product managers to deliver products

Mend.io is an equal opportunity employer committed to diversity and inclusion.