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 adaptable, 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, br

📌 Mid/Senior AI LLM Engineer (Barcelona)
🏢 EverAI
📍 Barcelona