Senior R&D Engineer (NLP/GenAI)

Our client has been into AI before it was cool and has gathered tons of research knowledge on AI, LLMs, RAGs being a personal research assistant to a solid client base. As part of their growth, they are looking for a Senior R&D Engineer (NLP/GenAI) to join their team.

In this role, you will work on hard, unsolved problems in modern language models. You’ll drive novel research directions, build prototypes, conduct experiments, and help turn them into production capabilities. You will also play a key role in securing research funding through high-quality grant proposals.

Day-to-Day:

• Design and implement novel NLP & ML methods (from theory to code).
• Run end‑to‑end experiments: data, training, evaluation, ablations.
• Translate research insights into prototypes and production features.
• Collaborate closely with engineers and product teams.
• Publish, present, and engage with the AI research community.
• Lead and co‑author EU and national research grant proposals.
• Write and publish research articles.

Research Directions (the exact mix will evolve based on your strengths and interests):

• LLM evaluation & uncertainty – confidence estimation, answer relevance, and robustness in open‑book QA and RAG systems.
• Agentic reasoning & control – understanding when models should reason, stop reasoning, or act, including inference‑time steering.
• Translation & multilingual NLP – evaluation and system design for modern LLM‑based translation, including low‑resource languages.
• Your goal will be turning rigorous research into capabilities that real users can trust and use.

Tech stack:

• Languages: Python (strong OOP practices).
• ML: PyTorch, Transformers, TensorFlow.
• LLMs: Hugging Face, OpenAI, custom and fine‑tuned models.
• Systems: RAG pipelines, Multi-agent frameworks, Evaluation tools.
• Infra: AWS, Docker, Distributed computing.
• Practices: Git, CI/CD, reproducible research workflows.

Requirements:

• PhD in ML, NLP, Computer Science, or a related field.
• Strong, hands‑on experience with R&D grants and proposal writing (e.g. Horizon Europe, EIC, national or international research funding).
• 5+ years of industry or applied research experience.
• Strong background in NLP (transformers, semantic search, RAG).
• Hands‑on experience with GenAI, LLMs and their evaluation.
• Solid software engineering skills and experience with Python.
• Publications in ML/NLP conferences or journals.
• Able to work within European time zones.

In Return, They Offer:

• 100% Remote policy with hybrid options for Sofia, Bulgaria.
• 30 days vacation + 5 additional days for learning and development.
• A job with a global mission to advance Science.
• Annual Salary Review.
• Share incentivization plan.
• Flexible work hours.
• Personal equipment reimbursement program.
• Free MultiSport card (BG).
• Private Health Insurance – premium package (BG).
• Career Enhancement plan.
• Workshops, Conferences, Hackatons, Tech Deep Dives (internal & external).

(Recruitment License № 2709/ 17.01.2019)