Fit4Me is looking for a Middle Back-End Developer who will help build and scale the backend of our Health & Fitness product, creating server-side solutions that directly impact user personalization, product stability, and the speed of delivering new features.
One of the key focus areas of this role will be developing backend services, the admin panel, and internal tools that power content management, personalized workout programs, and the core business logic behind our product.
You will work on functionality that allows users to personalize their workout experience by customizing exercises, reordering workout flows, switching between personal plans, and interacting with the product in a more flexible way. You’ll also contribute to the evolution of our backend architecture, integrate new services, and continuously improve our technical platform as the product grows.
This role is a great fit if you:
Want to build functionality that directly impacts the experience of thousands of users.
Enjoy working with business logic, APIs, and backend architecture.
Thrive in a product team where ownership, autonomy, and responsibility are valued.
Like designing clean, maintainable, and scalable backend solutions.
Want to see how your technical decisions contribute to product growth.
Your area of Impact:
Develop and maintain backend functionality for our mobile product, admin panel, and internal services.
Build and support REST APIs for the mobile application and internal tools.
Develop features that power workout personalization, content management, and user journeys.
Design new data models, extend business logic, and improve the existing backend architecture.
Work with MongoDB (Mongoose), PostgreSQL, and Redis.
Build integrations with external services, webhooks, and AWS.
Manage file storage and media assets using AWS S3.
Implement and maintain secure authentication and authorization mechanisms using JWT and OAuth.
Optimize database performance, improve query efficiency, and contribute to data migration between different storage solutions.
Collaborate closely with Product Managers, Designers, and Engineers to deliver new product capabilities.
Contribute to technical documentation and continuously improve backend architecture and engineering practices.
Tech stack: Node.js, TypeScript, PostgreSQL, MongoDB, Redis, REST API, Swagger / OpenAPI, AWS, JWT / OAuth, Git.
What do you need to join us:
3+ years of commercial experience as a Back-End Developer.
Strong hands-on experience with Node.js and TypeScript.
Practical experience working with MongoDB and Mongoose.
Experience with PostgreSQL or other relational databases.
Experience working with Redis.
Hands-on experience building and maintaining REST APIs.
Understanding of scalable backend architecture principles.
Experience integrating external services and working with webhooks.
Solid understanding of authentication and authorization mechanisms (JWT, OAuth).
Experience working with AWS (experience with AWS S3 is a strong plus).
Experience using Git in a collaborative development environment.
Understanding of clean architecture principles, REST, and SOLID.
Ownership mindset, analytical thinking, and the ability to work independently.
Nice to have:
Experience working with RabbitMQ or other messaging/queue systems.
Experience using Docker.
Hands-on experience with Swagger / OpenAPI.
Understanding of ACID principles and database transactions.
Experience working with ORM frameworks such as TypeORM, Sequelize, or similar.
Experience participating in database migration projects between MongoDB and SQL.
Experience working with payment systems, subscriptions, billing, or financial integrations.
Experience building backend systems for mobile products.
Understanding of logging, monitoring, and basic observability practices.
What we offer:
Fully remote work with a flexible schedule and dedicated business hours for collaboration.
A high level of autonomy, trus
