Simple

Senior Backend Engineer

Poland
Python Django FastAPI API PostgreSQL AWS Go Ruby LLM Machine Learning
Description

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!

Simple
Simple

0 applies

0 views

There are more than 50,000 engineering jobs:

Subscribe to membership and unlock all jobs

Engineering Jobs

60,000+ jobs from 4,500+ well-funded companies

Updated Daily

New jobs are added every day as companies post them

Refined Search

Use filters like skill, location, etc to narrow results

Become a member

🥳🥳🥳 452 happy customers and counting...

Overall, over 80% of customers chose to renew their subscriptions after the initial sign-up.

To try it out

For active job seekers

For those who are passive looking

Cancel anytime

Frequently Asked Questions

  • We prioritize job seekers as our customers, unlike bigger job sites, by charging a small fee to provide them with curated access to the best companies and up-to-date jobs. This focus allows us to deliver a more personalized and effective job search experience.
  • We've got over 200,000 jobs from 15,000+ vetted companies. No fake or sleazy jobs here!
  • We aggregate jobs from 15,000+ companies' career pages, so you can be sure that you're getting the most up-to-date and relevant jobs.
  • We're the only job board *for* software engineers, *by* software engineers… in case you needed a reminder! We add thousands of new jobs daily and offer powerful search filters just for you. 🛠️
  • Every single hour! We add 2,000-3,000 new jobs daily, so you'll always have fresh opportunities. 🚀
  • Typically, job searches take 3-6 months. EchoJobs helps you spend more time applying and less time hunting. 🎯
  • Check daily! We're always updating with new jobs. Set up job alerts for even quicker access. 📅

What Fellow Engineers Say