ML Engineer

Listed as a remote role based in Portugal. We are hiring for a rapidly growing company that provides marketing automation tools, focusing on building an intelligence layer that empowers small businesses to achieve better marketing outcomes through data-driven predictions and actions. This is an opportunity to join a dynamic, remote-first ML team and play a pivotal role in shaping the future of their predictive capabilities. The Role • Own the correctness of predictive models processing billions of behavioral events for engagement prediction, send-time and audience optimization, and list health. • Act as the primary reviewer for the team, ensuring data representativeness, sampling, labeling, and evaluation designs are robust. • Manage the transition of models from offline evaluation to production, including CI gates, drift monitoring, A/B testing, and retraining. • Leverage deep LLM training experience for fine-tuning and self-hosting models, focusing on evaluation and guardrails for real-world applications. • Mentor and elevate other engineers on the team through code reviews and knowledge sharing. What You'll Need • 5–8+ years of experience shipping and owning ML models in production. • A proven ability to identify and rectify silent failure modes such as bias, sampling issues, and temporal leakage. • Deep understanding of applied fundamentals for imbalanced and time-series problems. • Mature MLOps practices, including monitoring, A/B testing, retraining pipelines, and cost management. • Hands-on experience with LLM fine-tuning, ideally on self-hosted infrastructure. • Fluency in Python and the modern ML ecosystem (scikit-learn, gradient boosting, pandas/Polars, PyTorch). What's On Offer • Competitive annual salary (€75,000 - €100,000) plus additional benefits. • A remote-first culture with significant autonomy and a bias towards shipping. • Company-paid global retreats and a generous vacation policy. • Comprehensive parental leave and a dedicated parenting budget. Apply via Haystack today! Show more Show less Seniority level Mid-Senior level Employment type Full-time Job function Information Technology Industries Technology, Information and Internet