Performance Engineer- Hybrid Working

components - Build and maintain high-load, low-latency backend services - Work on in-house solutions including: - Feature stores - User identity services - Custom inference layer - ML platform infrastructure - Optimize system performance across on-premise Docker & Kubernetes environments - Design and implement solutions for traffic scaling and system reliability - Collaborate with ML, data, and engineering teams to support production ML systems - Continuously improve system architecture, observability, and efficiency - Languages: Rust, Python - Tools: GitHub Requirements - 5+ years of experience in software engineering - Strong proficiency in Rust, or proficiency in C/C++/Zig with willingness to transition to Rust - Experience designing and building high-load, performance-critical systems - Solid understanding of system design, concurrency, and performance optimization - Basic knowledge of machine learning workflows and tools Nice to Have - System programming experience

(C, C++, Zig) - Experience in ML engineering / MLOps - Familiarity with AdTech standards (OpenRTB, MRAID, VAST) - Experience with WASM / WASI - Background in distributed systems and real-time processing - Location: Barcelona, Spain (office attendance 4 days per week) What We're Looking For - Autonomous and self-driven engineer with strong ownership mindset - Passion for engineering excellence, performance, and scalability - Interest in ML/AI systems and infrastructure - Ability to work independently and make informed decisions - Strong collaboration and communication skills Why Join Us - Opportunity to work on cutting-edge projects with a global impact in the mobile app industry - A collaborative and inclusive work culture that values innovation and continuous learning - Competitive salary, flexible work arrangements, and a comprehensive benefits package - Professional development opportunities and career growth prospects within a fast-growing

Appodeal is a dynamic US-based product company with a truly global presence. We operate from offices in Warsaw, Barcelona and Parkland (FL) and have a worldwide distributed team. Our mission is to help people discover and grow their talents through products that enable successful mobile app businesses. About the Role We are looking for a Senior Rust Engineer to join our Barcelona team and contribute to building high-performance, real-time systems powering our ML-driven AdTech platform (Mobile Growth Platform). In this role, you will work on core backend infrastructure and ML platform components, focusing on low-latency, high-load services that process large-scale traffic in real time. You will play a key role in developing and optimizing systems such as real-time applications, feature stores, user identity services and custom inference layers, ensuring scalability, reliability, and performance. Responsibilities - Contribute to the development of real-time applications and ML platform