LLM Engineer - Post-Training (Remote - Europe)

Location: Europe Workplace: Remote OUR VISION & PRODUCTS 🚀 EverAI — Building the Future of AI Companionship One of the Top 15 Largest & Fastest-Growing AI Companies in the World 50 Million Users in 2 years — Help Us Reach 100M first, 500M next At EverAI, we’re shaping what it means to connect with AI. With 50 million users and counting, we're not just building products — we're creating entirely new categories. Our flagship product is the world’s largest AI companionship platform, redefining relationships for millions. It is governed by our proprietary moderation system, EverGuard — an internal AI designed to ensure everything we build is safe, ethical, and human-first. And we’re only just getting started! OUR TEAM We are an enthusiastic, passionate and hardworking team of ≈ 100 people. Our founding team has strong entrepreneurial experience building and scaling web products from 0 to IPO. Alexis Soulopoulos [CEO] • 10+ years in Tech Executive Leadership • Co-Founder Mad Paws Holdings (from 0 to IPO) • Forbes 30 under 30 + Deloitte TechFast50 ’22 & ‘23 Michael Monin [Co-founder & CTO] • 10+ years as CTO / COO (web2/web3), 3 years in AI/LLM • Serial-entrepreneur: MTK Digital (exited / 0->$20m revenue) and Zipchat (AI Chatbot for E-commerce brands) Thomas Lacroix [Co-founder & CMO] • 8+ years in Customer Acquisition & E-commerce Growth • Serial-entrepreneur: Curatible (sold to Blackstone) and MTK Digital (exited / 0->$20m revenue) Maruša Fasano [CFO/Legal] • 25+ years in Finance, Strategy, M&A • Ex-CFO/M&A @Curatible (exited to Blackstone) • Ex-President of the Board @SotremoSA (exited) • Co-founder/CFO @SoftOne (exited) YOUR ROLE Most LLM roles stop at experimentation. Here, the models you improve power experiences for 50M+ users. Most of our traffic runs on self-hosted, fine-tuned open-weight models. On our internal roleplay evals, our smaller fine-tuned models can outperform much larger off-the-shelf models. Your job is to make them better. You’ll join a small AI team led by Marco, our LLM Tech Lead, working closely with our CTO, Product, Web and DevOps teams. You’ll work across data, post-training, evals, and model behavior, taking ideas from failure analysis to production. The problems are real: personalization, character consistency, long conversations, better evals, multilingual behavior, and faster training cycles. If you want to shape model behavior at consumer scale, this is the role. 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. Decide whether the answer is better 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 to production and use real user behavior to guide the next iteration - Speed up the training loop so experiments are faster, easier to compare, and more reproducible YOUR QUALIFICATIONS - You’ve personally post-trained open-weight LLMs for a user-facing product and shipped them to production - You’ve worked where AI was core to the product or business, not an experimental side feature - Fine-tuning is core to your experience - Strong Python, PyTorch and Hugging Face, with hands-on GPU training and debugging - You build data and evals yourself and make decisions from evidence - You can take work beyond notebooks into production - You use AI tools daily in your own engineering work - You are fully comfortable working with uncensored models and explicit NSFW content, including harmful material when developing and evaluating moderation system 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 WHY EVERAI? 📈 Exponential Growth: From 50M users in 2 years, to 100M next — and 500M beyond 🚀 Track Record of Category-Creating Innovation: We consistently launch world-first AI applications — setting the pace, not following it 🌍 Global Impact: Top-tier user growth, real-world adoption, and cultural relevance 🧠 Proven Leadership: A senior team that’s launched, scaled, and exited & IPO’d multiple scale ups — now fully focused on reshaping AI companionship 👥 Elite Remote Team: 100% remote and built to win — world-class talent from Tier 1 tech companies, with a culture of ownership, velocity, and radical creativity 🛡️ Ethical Core: Our AI ecosystem is governed by EverGuard, our proprietary AI moderation technology, ensuring responsible development at scale WHAT WE OFFER ✍️ Contract Type: We prefer B2B, but we’re flexible, what matters is long-term commitment and impact 📍 Work From Anywhere: Fully remote. Choose the environment where you do your best work 🏝️ Paid Time Off: 4 weeks (20 working days) of PTO per year to recharge and reset 👨‍👩‍👧‍👦 Annual Gathering: A yearly in-person meetup to connect, brainstorm, and celebrate wins together ❤️‍🩹 Health & Wellness Support: Monthly allowance of 100 USD for health insurance expenses & access to unlimited 1:1 sessions with psychologists and lifestyle experts through OpenUp (also available to up to three of your family members) 🏢 Co-Working Space Budget: Work from a co-working space up to twice per month (35 EUR / 40 USD per visit) to stay inspired and connected 📚 Learning Budget: Dedicated funds to support your professional growth: courses, books, conferences, events, or certifications 💻 Company Laptop & Equipment: Laptop provided + monitor budget up to 250 USD + keyboard/mouse/mic/headphones budget up to 150 USD ⚡ AI Tools Access: Premium access to ChatGPT, Hugging Face, Claude Code, and any other tool needed to excel at your job, power your ideas and workflows 🎯 TOP TIER TALENT IS OUR MULTIPLIER We’re a fully remote group of A-players from Tier 1 tech, led by an exec team who’ve launched, scaled, and exited multiple companies. We move fast, and care deeply about what we build — and who we build it with. We’re looking for exceptional talent ready to ship & distribute world-first AI products at scale, fast, and co-create with us this category-defining business. If that’s you — reach out and apply!