Backend Tech Lead (AI/Python)

TL;DR

Backend Tech Lead (AI/Python): Taking technical ownership of a backend platform for an AI Fitness Personal Trainer, evolving it from a consumer product to support large-scale partnerships and high growth, with an accent on integrating AI/LLM models, managing data flows, and scaling AI-backed features. Focus on designing robust, high-performance, and reliable backend services for high load and reliability, as well as shaping future backend architecture and engineering practices.

Location: Hybrid in Poland

Company

hirify.global is the world’s first AI Fitness Personal Trainer, revolutionising health and wellness with smart, personalised, AI-powered guidance.

What you will do

• Take ownership of the current backend architecture and evolve it to handle high load, burst traffic, and partner-driven scale.
• Design and operate backend services that integrate with LLMs and bespoke ML systems.
• Write production code on critical backend paths and deliver product features and technical improvements.
• Design and optimize systems for performance, throughput, and resilience, especially with relational databases.
• Own and improve APIs between backend services, mobile applications, and AI components.
• Lead architectural discussions for new features and major changes, influencing engineering practices and decision-making.

Requirements

• Strong backend engineering experience with Python (Django and/or FastAPI).
• Proven experience scaling backend systems for performance, reliability, and high load.
• Deep experience with relational databases (PostgreSQL preferred), including schema design and query optimization.
• Hands-on experience with message-based systems (e.g., RabbitMQ).
• Experience running backend systems on cloud infrastructure (AWS or equivalent).
• Strong understanding of API design for backend ↔ mobile client interactions.
• A clear delivery mindset and architectural judgment.
• Fluent English.

Nice to have

• Experience in other languages like Go.
• Experience designing systems for large partners or enterprise-scale usage.
• Experience with CI/CD pipelines and production operations.
• Interest in health, fitness, or consumer-facing products.

Culture & Benefits

• Be part of a fast-growing fitness and lifestyle startup.
• Work with AI and LLMs as a core product and software development methodology.
• Directly impact product and architecture decisions.
• Experience both B2C scale and large B2B for AI-driven product features.
• Opportunities for growth by taking on larger technical problems and broader influence.
• Enjoy an excellent, person-oriented work environment within a smaller company.