Mid/Senior AI LLM Engineer (Full Remote - Europe)

EverAI Limited; Polska; Hybrid; PLN 466,000 - 700,000; Full time

Benefits offered by this job

Fully remote work

4 weeks PTO per year

Learning budget

Company laptop & equipment

AI tools access

Job summary

EverAI Limited is hiring for a role that powers the world's largest AI companionship platform. You will fine-tune open-weight LLMs and drive improvements across personalization, multilingual behavior, and safety, working with data, post-training, evals, and production systems.

This is a fully remote, international position with a strong emphasis on production-quality workflows and scalable experimentation. You will collaborate closely with data science, product, and DevOps teams to push models

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 feature.
• Fine-tuning is central to your experience.
• Strong Python, PyTorch and Hugging Face skills with hands-on GPU training and debugging.
• You build data and evals yourself and drive decisions from evidence.
• You take work beyond notebooks into production.
• You autonomously use AI tools in engineering work.
• You are comfortable with uncensored models and explicit NSFW content for moderation development.

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, deciding data, post-training, prompting or classifiers.
• Build training data and evals that shape next training iterations.
• 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 to make experiments faster, easier to compare, and more reproducible.

Skills

Post-trained LLMs

Python

PyTorch

Hugging Face

Data & evals

Production deployment

AI tooling daily use

Tools

PyTorch

Hugging Face

Job description

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 of100 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