Senior Backend Developer
Zing Coach is the world’s first AI Fitness Personal Trainer, revolutionising the way people approach health and wellness. Four years ago, we set out to replace traditional PT sessions with smart, personalised, motivating guidance powered by AI. We’re not just another app – we’re a movement, on a mission to help everyone reach their full physical and mental potential.
We are looking for a Senior Backend Engineer to build and evolve backend services that power the Zing Coach product. This is a hands-on individual contributor role focused on shipping high-quality backend code, improving existing systems and approaches, and taking responsibility for production behaviour.
Responsibilities
Backend feature development
Design and implement backend features supporting core product experiences
Take work from ideation through deployment and production support
Design backend-first architecture used by mobile clients and internal services
AI-backed product functionality
Integrate backend with LLM-powered and ML-based systems
Handle latency, failure modes, and operational concerns around AI dependencies
System improvement and scaling
Improve performance, scalability and reliability of existing backend services
Work with relational databases: schemas, queries, migrations, and performance issues
Collaborate closely with mobile, ML, and product managers to deliver features end-to-end
What we expect that you have
Must-have
Strong backend engineering experience with Python (Django and/or FastAPI)
Experience building and operating high-load backend systems
Experience with asynchronous systems
Good understanding of API design for backend ↔ client communication
Solid experience with relational databases (PostgreSQL preferred)
Strong execution and ownership mindset
Fluent English
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
Fluent English
Why working at Zing is awesome
Be part of the fastest-growing fitness and lifestyle startup
AI and LLMs are core to the product and part of how we build software day to day
Backend systems with real scale, real users, and real constraints
AI-driven product where backend reliability and performance matter
Small team, high trust, and room to grow through responsibility
Come be a part of something extraordinary at Zing AI Coach – where innovation meets inspiration, and every day brings new opportunities for growth and impact.
If you are passionate about understanding user needs and contributing to the development of a user-centered product, we would love to hear from you. Join us and help us create an exceptional user experience for Zing Coach!
- Brand
- Zing
- Locations
- Poland
- Remote status
- Hybrid
- Employment type
- Full-time
- Department
- Engineering
About Palta (Simple / Zing / Lovi)
Palta is a health & well-being technology company. We're guided by real passion and curiosity to transform bright ideas into worldwide products while delivering real results.