Senior Software Developer

O projekcie: Job title: Senior Backend Developer  Location: Poland  Work mode: 100% remote Type of cooperation: B2B contract Salary range: B2B: 4500 - 6000 EUR net /month About the company/project: Let’s get straight to the point - we’re building the next chapter in interactive fitness. We’re a team of tech-driven fitness enthusiasts who believe that working out should be something people actually enjoy. So we started designing. From the ground up. The result? A one-of-a-kind device — a smart IoT-powered strength training machine that combines advanced hardware with an AI-powered personal coach. It’s built for effective, personalized strength workouts at home, with real-time feedback, tracking, and progress you can feel. This project is being developed for an Israeli startup in the fitness space, aiming to redefine how people train at home through a truly innovative product. Our team brings together experienced designers, product managers, and top-tier software and hardware engineers - many of whom have worked on some of the most recognized consumer tech products out there. Now, we’re combining our skills to build something that will reshape home fitness — engaging, effective, and genuinely rewarding. Backend Developer with Frontend skills as a plus  Workplace: An office in Warsaw, possibility to work 100% remotely  What we offer: - Working in internaitonal environment - Flexible working hours - Participation in greenfield projects - Long-term cooperation - No dresscode - Private healtcare package - Multisport card Wymagania: You are an ideal candidate if you have: - Experience as Software Engineer with 5+ years of hands-on experience in backend development, preferably in high-performance, low-latency environments - Experience with Node.js, Typescript and some react - Experience in cloud platforms, particularly AWS, and familiar with serverless architecture and microservices - Hands-on experience with NoSQL data stores like DynamoDB, Elasticsearch, etc. - A problem-solving attitude, eager to tackle performance and efficiency challenges in backend systems - Experience in startup environment Nice to have: - Experience in multiple front-end platforms e.g. iOS, React, Android, and API services - Experience with Swift/SwiftUI - Experience integrating GenAI technologies - Degree in Computer Science or similar Codzienne zadania: - Design and implement highly scalable and performant backend systems, focusing on low latency and high throughput. - Develop complex, scalable backend services from the ground up using cutting-edge technologies such as serverless architecture, AWS, and big data. - Deliver high-quality software on time by collaborating with the team on backend optimizations, and taking ownership of the process - Utilize Continuous Integration & Delivery and/or Test-Driven Development to ensure code quality, performance, and reliability. - Conduct performance profiling and tuning on backend systems to achieve optimal efficiency.