Tech Lead, LLM & Generative AI (Full Remote - Spain)

8+ years of engineering experience, with a significant portion dedicated to shipping ML/LLM features to millions of active users. Proficient in Python/PyTorch and comfortable with the modern LLM stack (vLLM, HuggingFace, fine-tuning pipelines, eval frameworks). Understand the technical rigor required to moderate NSFW content effectively without breaking the user experience. Intuition for LLM alignment: understand how prompt conditioning, temperature, and sampling affect chatbot behavior. Value velocity and distinguish between academic and shippable production solutions. Obsess over metrics, regressions, and user experience.

Act as a Player/Coach: architect the system, mentor the team, and spend significant time hands-on in the codebase (Python/PyTorch). Own the core chat loop: Optimize context windows, memory/RAG retrieval, and inference latency. Drive the strategy for SFT (Supervised Fine-Tuning) and RLHF/DPO (Preference Optimization). Manage the 'Data Engine': oversee sourcing, labeling, and cleaning of diverse datasets. Design and train custom classifiers to detect and filter non-consensual or illegal content within an explicit environment. Create nuanced, context-aware moderation systems.