Principal Fullstack Engineer (AI)

TL;DR

Principal Fullstack Engineer (AI): Building and optimizing a central GenAI Platform and AI agents to empower product teams with scalable capabilities for rapid development, validation, and deployment. Accent on designing and shipping full-stack systems, shaping platform capabilities, and directly contributing to impactful AI agents. Focus on applying current LLM patterns (RAG, retrieval, routing, tool-use, evals) to deliver measurable customer value in terms of faster, more reliable AI systems, improved trust/safety, and lower cost per query, while also mentoring engineers and driving architecture.

Location: Hybrid (8 days/month in office). Must be based in Warsaw, Poland.

Company

hirify.global is a dynamic global technology company providing expert software and information solutions that professionals rely on to advance sustainability, health, justice, prosperity, and commerce worldwide.

What you will do

• Design and implement full-stack applications, AI agents, and platform components that enable rapid GenAI agent development, validation, and deployment.
• Build developer tooling, CI/CD, and observability for safe, fast iteration, including evaluations, canaries, rollout/rollback, and cost/quality telemetry.
• Apply secure SDLC and privacy-by-design practices, such as threat modeling and least privilege.
• Collaborate with product, UX, and domain experts to deliver customer-focused solutions with measurable outcomes.
• Apply current LLM patterns (RAG, retrieval, routing, tool-use, evals) to deliver faster, more reliable AI systems, improved trust/safety metrics, and lower cost per query.
• Lead by example and be heavily hands-on, driving architecture, mentoring engineers, and taking ownership of larger projects.

Requirements

• 8+ years of professional software engineering experience.
• Strong full-stack development skills and cloud experience (AWS/Azure/GCP).
• Expertise in at least one, and proficiency across others, including AI Agent development and evaluation, backend/frontend development, cloud services, CI/CD, Infrastructure as Code, SRE, QA, secure SDLC, and privacy by design.
• Proven track record delivering secure, reliable, cloud-native systems to production.
• Excellent problem-solving, ownership, and cross-functional communication skills.

Nice to have

• Proven ability to deliver software products independently or as part of a small, fast-paced team.
• Experience taking AI agents from concept to production, including safety evaluations and iterative testing.
• Experience with LangChain/LangGraph and MCP, vector/RAG systems, and OpenSearch.
• Understanding of LLMs, their failure modes, and techniques like fine-tuning and model adaptation.
• Familiarity with regulatory frameworks such as SOC2 and HIPAA.

Culture & Benefits

• Join a dynamic global technology company focused on making a difference in critical industries.
• Work within a 100-engineer team, combining the stability of an established company with the agility of a startup.
• High-autonomy, high-impact role with opportunities to lead and mentor less experienced engineers.
• Thrive in a caring and inclusive culture that values diversity and personal growth.
• Contribute to advancing sustainability, health, justice, prosperity, and commerce around the world.

Hiring process

• 15-minute intro screen.
• Two live coding sessions in your preferred language.
• One systems design session.
• One presentation of past work.
• Timeline: Typically 2–4 weeks.