Mid/Senior AI LLM Engineer - EverAI

About EverAI

EverAI is building the future of AI companionship. As one of the top 15 largest and fastest-growing AI companies in the world, we reached 50 million users in just 2 years and are scaling toward 100M and 500M users. Our flagship product is the world's largest AI companionship platform, governed by our proprietary moderation system, EverGuard.

Your Role

Most LLM roles stop at experimentation. Here, the models you improve power experiences for 50M+ users. Much of our traffic runs on self-hosted, fine-tuned open-weight models that outperform much larger off-the-shelf models on our internal evals.

You will join a small AI team working closely with our CTO, Product, Web, and DevOps teams across data, post-training, evals, and model behavior. Solve real challenges in personalization, character consistency, long conversations, multilingual behavior, and faster training cycles.

Key Responsibilities

• Fine-tune open-weight LLMs using SFT, LoRA/QLoRA, and post-training methods such as DPO and GRPO.
• Diagnose model failures and turn them into experiments (data, post-training, prompting, or classifiers).
• Build training data and evals that directly shape what gets trained next.
• Improve model behavior across personalization, consistency, tone, multilingual, and group interactions.
• Ship models to production and use real user behavior to guide the next iteration.
• Speed up the training loop to make experiments faster, easier to compare, and more reproducible.

Qualifications

• Personally post-trained open-weight LLMs for a user-facing product and shipped them to production.
• Worked where AI was core to the product or business, not an experimental side feature.
• Strong expertise in fine-tuning, Python, PyTorch, and Hugging Face, with hands-on GPU training and debugging.
• Build data and evals independently and make data-driven decisions.
• Ability to take work beyond notebooks into production.
• Use AI tools daily in your own engineering work.
• Fully comfortable working with uncensored models and explicit NSFW content, including harmful material when developing and evaluating moderation systems.

Bonus Points

• Experience with conversational AI, roleplay products, or highly personalized consumer AI
• Multilingual LLMs
• Moderation, safety, or adversarial testing
• Multimodal models
• Open-source LLM / post-training contributions

What We Offer

• Contract Type: B2B preferred with long-term commitment and impact
• Work From Anywhere: Fully remote across Europe
• Paid Time Off: 4 weeks (20 working days) of PTO per year
• Annual Gathering: Yearly in-person meetups
• Health & Wellness Support: Monthly allowance of $100 for health insurance & unlimited 1:1 sessions with psychologists and lifestyle experts via OpenUp (plus family access)
• Co-Working Space Budget: Co-working space access up to twice per month (up to $40 per visit)
• Learning Budget: Dedicated funds for courses, books, conferences, and certifications
• Equipment: Company laptop provided + monitor budget up to $250 + peripheral budget up to $150
• AI Tools Access: Premium access to ChatGPT, Hugging Face, Claude Code, and other required tools