Senior ML Researcher: End-to-End Fine-Tuning & RL Innovation

Toloka; España; Remote; EUR 90,000 - 130,000; Full time

Benefits offered by this job

Remote work

Competitive compensation + ESOP

PTO & benefits

Job summary

Toloka AI is a remote-first company powering GenAI models with a global team. You will own Toloka’s end-to-end fine-tuning, RL, and evaluation stack, turning complex ML experiments into scalable platform features and collaborating with engineers to deliver end-to-end solutions for clients.

The role spans data prep, model distillation, evaluation, and improving the platform through prompt/tool design and human-judged evaluation loops. English proficiency required.

Qualifications

• 4+ years in ML engineering or applied research.
• Hands-on with LLMs in production or research settings.
• Experience fine-tuning open-weight models (LoRA/full FT) and data curation.
• Strong Python and PyTorch; familiar with the Hugging Face ecosystem.

Responsibilities

• Own end-to-end fine-tuning pipelines: data prep, training, distillation, evaluation, serving.
• Extend post-training stack into RL and reward modeling; design user-facing RL flow.
• Build and calibrate evaluation harnesses with LLMs as judges against human labels.
• Improve the platform's guiding agent: prompts, tools, eval loops.
• Run experiments for client projects and translate results into platform features.
• Collaborate with platform engineers on SDK/API surfaces for training/eval jobs.

Skills

ML engineering

Applied research

LLMs in production

Python

PyTorch

HF ecosystem

Tools

vLLM

Transformers

Job description

Toloka AI is a remote-first company powering GenAI models with a global team. You will own Toloka’s end-to-end fine-tuning, RL, and evaluation stack, turning complex ML experiments into scalable platform features and collaborating with engineers to deliver end-to-end solutions for clients.

The role spans data prep, model distillation, evaluation, and improving the platform through prompt/tool design and human-judged evaluation loops. English proficiency required.