Senior MLOps Engineer at Appodeal

<div class="content-intro"><p><strong>Appodeal</strong> is a dynamic US-based product company with a truly global presence.</p> <p>We have offices in <strong>Warsaw, Barcelona and Parkland (FL), </strong>along with remote team members located around the world.</p> <p>Our company thrives on diversity, collaboration, and innovation, making us a leader in the mobile app monetization space.</p> <p><strong>Why Appodeal?</strong></p> <p>At Appodeal, we’re more than just a company—we’re a team united by a common mission: <strong>Help people discover and grow their talents through products that enable successful mobile app businesses!</strong></p> <p>We take pride in our cutting-edge product and our internationally dispersed team of talented professionals.</p> <p>Here’s what we value, and what we hope you do too:</p> <ul> <li><strong>Continuous Learning and Growth:</strong> We are passionate about learning, growing personally, and building rewarding careers.</li> <li><strong>Making an Impact:</strong> We are committed to building a history-defining company that leaves a lasting impact on the mobile app industry.</li> <li><strong>Solving Exciting Challenges:</strong> We tackle complex problems every day, supported by a team of world-class professionals and mentors.</li> <li><strong>Enjoying the Journey:</strong> We believe in having fun while working toward our goals.</li> </ul></div><p>We are looking for a <strong>Senior MLOps Engineer</strong>&nbsp;to add to our <strong>Data team in Barcelona.</strong></p> <p>Join the User Acquisition MLOps team that builds the core ML backbone of Appodeal. We design and run the systems that power real-time predictions at massive scale, where every millisecond matters. Our work directly drives thousands of bidding operations each second, supporting a high‑throughput, low‑latency inference platform used across the company.</p> <p>You will help shape and evolve a modern ML platform built around Databricks, MLflow, Unity Catalog, GitHub Actions, and deep integrations with our Predictor service. This means solving real engineering challenges: scaling training pipelines, optimizing GPU workloads, ensuring safe and automated model promotions, and keeping online inference reliable under extreme load.</p> <p>You will collaborate daily with Data Science, Data Engineering, Runtime, DevOps, and Product, and you will fully own the systems and projects you touch. This is a role for engineers who like autonomy, impact, and building things that matter.</p> <h4>Responsibilities:</h4> <ul> <li>Design, operate, and improve the ML platform, including Databricks workflows for training, MLflow and Unity Catalog for model management, CI/CD pipelines using GitHub Actions and Databricks Asset Bundles, and integration with the runtime inference layer.</li> <li>Support data scientists in developing and maintaining end-to-end training pipelines, covering data processing, feature transformations, ML model training on GPUs, and distributed training setups to ensure efficient and scalable workflows.</li> <li>Ensure reliable and safe model inference by validating models before promotion, checking metadata compatibility, monitoring latency, and supporting model evaluation flows.</li> <li>Maintain strong ML observability, including online and offline monitoring, data and feature parity checks, and automated validation of model performance in production.</li> <li>Develop internal tools and APIs that enable DS teams and account managers to experiment, validate, and promote models efficiently while reducing operational friction.</li> </ul> <h4>Requirements:</h4> <ul> <li>3+ years of experience in MLOps, ML Platform Engineering, or Backend roles supporting production ML systems.</li> <li>Strong Python and software engineering skills, with experience building and maintaining APIs (FastAPI, Flask, or similar).</li> <li>Hands-on experience with DNNs using PyTorch or other modern deep learning frameworks, including GPU training and optimizing hardware utilization.</li> <li>Solid understanding of distributed computing and data processing using Apache Spark or similar frameworks.</li> <li>Experience with Databricks (Jobs, MLflow, Delta, UC) or an equivalent cloud-based ML platform.</li> <li>Strong understanding of the ML lifecycle: data ingestion, experimentation, model packaging, deployment, and monitoring.</li> <li>Familiarity with real-time model inference systems and ensuring compatibility with downstream services.</li> <li>Experience with data validation libraries (Pydantic or similar) used within ML and API workflows.</li> <li>Good understanding of Docker containers, Kubernetes, and basic networking concepts.</li> <li>Experience creating and maintaining CI/CD pipelines (GitHub Actions or similar).</li> <li>Experience with orchestration tools (Databricks Jobs, Dagster, Airflow or similar).</li> <li>Demonstrated ability to use modern AI tools (Claude, ChatGPT, Gemini) to improve development speed and quality.</li> <li>Proactive mindset with a strong sense of ownership, consistently pushing work forward and anticipating next steps without needing close direction.</li> <li>Strong English communication skills.</li> </ul> <h4>Nice to have:</h4> <ul> <li>Exposure to very high-load, low-latency ML inference environments.</li> <li>Knowledge of distributed or large-scale ML training frameworks and multi-GPU setups.</li> <li>Familiarity with Databricks Asset Bundles.</li> <li>Understanding of ONNX or other portable model serialization formats.</li> <li>Ability to work with Rust programming language.</li> <li>Familiarity with transformer architectures, encoder-decoder models, or sequence modeling approaches.</li> <li>Exposure to data engineering concepts, such as building scalable data pipelines, understanding CDC patterns, or working with structured and unstructured datasets.</li> <li>Experience with MinIO or other S3-compatible storage systems.</li> <li>Understanding of networking protocols such as TCP, HTTP, and gRPC, including their limitations in low-latency scenarios.</li> <li>Confidence navigating the Atlassian ecosystem (Jira, Confluence, Compass).</li> </ul> <p>This position supposes relocation to&nbsp;<strong>Barcelona</strong> and work from our office in the city center.</p> <p><strong>Why Join Us:</strong></p> <ul> <li>Opportunity to work on cutting-edge projects with a global impact in the mobile app industry.</li> <li>A collaborative and inclusive work culture that values innovation and continuous learning.</li> <li>Competitive salary, flexible work arrangements, and a comprehensive benefits package.</li> <li>Professional development opportunities and career growth prospects within a fast-growing company.</li> </ul><div class="content-conclusion"><p>With an outstanding product and a mission that excites and inspires, Appodeal offers a unique opportunity to make an impact while being part of an amazing team.</p> <p><strong>Join us</strong> and help shape the future of mobile app success!</p></div>