Senior Backend Engineer (AI)

TL;DR

Senior Backend Engineer (Python/AI): Building and evolving backend services for an AI Fitness Personal Trainer product with an accent on API design, integration with LLM/ML systems, and scaling existing services. Focus on shipping high-quality code, improving system performance, and ensuring production reliability.

Location: Hybrid role based in Poland.

Company

hirify.global is the world’s first AI Fitness Personal Trainer, revolutionising the way people approach health and wellness as a health & well-being technology company.

What you will do

• Design and implement backend features supporting core product experiences.
• Integrate backend with LLM-powered and ML-based systems, handling latency and operational concerns.
• Improve performance, scalability, and reliability of existing backend services.
• Work with relational databases, including schemas, queries, migrations, and performance issues.
• Collaborate closely with mobile, ML, and product managers to deliver features end-to-end.

Requirements

• Strong backend engineering experience with Python (Django and/or FastAPI).
• Experience building and operating high-load backend systems with asynchronous systems.
• Good understanding of API design for backend ↔ client communication.
• Solid experience with relational databases (PostgreSQL preferred).
• Strong execution and ownership mindset.
• English: C1+ required.

Nice to have

• Experience working with cloud infrastructure (AWS or equivalent).
• Experience working on AI- or ML-enabled products.
• Experience with other languages (e.g., Go, Ruby).
• Interest in health, fitness, or consumer-facing products.

Culture & Benefits

• Be part of a fastest-growing fitness and lifestyle startup.
• Work with AI and LLMs as core to the product and part of daily software building.
• Engage with backend systems having real scale, real users, and real constraints.
• Work in an AI-driven product where backend reliability and performance matter.
• Small team with high trust and room to grow through responsibility.