4

42dot

Unified platform for multi-modal urban mobility

LLM Engineer - Data Generation

Natural Language Processing & LLMsConfirmed live in the last 24 hours
Full-timePangyo-ro, Bundang-gu, Seongnam-si, Gyeonggi-do, South KoreaNo salary listedHybrid

About the Job

Requirements

  • At least 3 years of work experience related to large language models, machine learning, or data generation.
  • A general understanding of deep learning, machine learning, and natural language processing.
  • Understanding of the composition, preprocessing, quality evaluation, and training use of model training data.
  • Ability to develop data processing and automation solutions using Python.
  • Experience or equivalent capability in processing, cleaning, filtering, and quality management of large-scale training datasets.
  • Experience generating synthetic data, evaluating data, or curating data using large language models.
  • Understanding of or experience using large language model APIs and prompting or generation strategies.
  • Problem-solving, collaboration, and communication skills.

Responsibilities

  • Collaborate with research and model training teams to analyze model performance bottlenecks, failure cases, and training objectives, and define data requirements.
  • Design, generate, and refine training data such as instruction, preference, reasoning, and domain-specific data.
  • Experimentally analyze the impact of generated data on model performance and iteratively improve data generation strategies based on results.
  • Design and operate automated training-data generation pipelines, including synthetic data generation.
  • Build workflows for large-scale data generation to provide a stable and efficient data production environment.
  • Continuously optimize pipelines for generation cost, processing speed, and quality.
  • Define quantitative and qualitative criteria for evaluating data quality and training effectiveness.
  • Validate data quality using large-language-model-as-a-judge methods, rule-based validation, and human feedback.
  • Develop iterative generation and filtering strategies to improve data quality.

Desired Qualifications

  • Experience building large-scale LLM training datasets for pre-training, supervised fine-tuning, or preference optimization methods such as DPO, RLHF, or RLAIF.
  • Experience with LLM evaluation frameworks such as OpenAI Evals, LM Evaluation Harness, or DeepEval, or building an in-house evaluation system.
  • Experience designing advanced LLM data for multi-turn conversations, tool calling, agents, reasoning, or code generation.
  • Experience building Python-based data pipelines or large-scale data processing environments using tools such as Airflow, Ray, or Spark.
  • Contributions to open-source projects related to generative AI, LLMs, or NLP, or experience presenting papers or technical talks.

About the Company

42dot

Unified platform for multi-modal urban mobility

42dot.ai provides a platform called UMOS (Urban Mobility Operating System) that connects and manages multiple transportation modes—such as cars and drones—within a single system for cities, agencies, and private clients. UMOS enables efficient transportation management, demand-response services, and smart logistics by integrating data and operations across modes, powering operations through a subscription-based platform-as-a-service model. Unlike single-mode solutions, 42dot.ai offers multi-modal, city-focused orchestration that bridges public, private, and logistics needs. The company aims to transform urban mobility by helping cities run more efficiently, cut costs, and improve the experience for commuters and logistics providers.

Company size
501-1,000
Company stage
Growth Equity (Venture Capital)
Total funding
$731.9M
Headquarters
Seoul, South Korea
Founded
2019

Recently Posted Jobs

Explore more opportunities at 42dot

See more jobs