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

EverAI Limited; Polska; Remote; PLN 330,000 - 549,000; Full time

Benefits offered by this job

Fully remote

4 weeks PTO

Annual in-person meetup

Health insurance stipend

Co-working budget

Learning budget

Company laptop

AI tools access

Job summary

EverAI Limited is seeking an experienced AI engineer to advance open-weight LLMs used by 50M+ users. You will fine-tune models, build data/evals, and push production-ready systems.

Join a fully remote team led by a strong leadership group; work across data, post-training, evals, and model behavior to deliver safer, personalized experiences at consumer scale.

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, 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

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

Skills

Post-trained LLMs

AI product mindset

Fine-tuning expert

Python PyTorch HF

Production deployment

Experimentation culture

NSFW content handling

AI tools daily

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

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)

Maruš̌a 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!

Compensation Range: €75K - €125K