Senior Principal ML Scientist: RL & LLM for Marketplaces

Grab; Singapore; On-site; SGD 180,000 - 260,000; Full time

Benefits offered by this job

Term Life Insurance

Medical Insurance

GrabFlex

Parental Leave

Birthday Leave

LASA Leave

Grabber Assistance Programme

Flexible Hours

Job summary

Grab is seeking a Senior Principal Data Scientist to lead automated marketplace optimization. You will design reinforcement learning systems that optimize pricing, dispatch, and supply repositioning, while architecting LLM-based behavioural intelligence at scale.

This role reports to the Head of Data Science and sits in Grab's One-North Singapore office. You will guide a small team, bridging research and production, and work with data engineers to deploy learning-driven solutions that scale

Qualifications

• PhD or equivalent with 10+ years leading research-to-production initiatives.
• Strong fundamentals in RL, control, and reward design for sequential decision problems.
• Experience deploying ML/RL systems in live environments with online learning or simulation-based optimization.
• Knowledge of world models, sequential modeling, and representation learning.

Responsibilities

• Design end-to-end RL systems that optimize pricing, dispatch, and supply repositioning.
• Build latent world models capturing supply-demand interactions and user signals.
• Develop multi-objective policies and safe deployment frameworks for production systems.
• Fine-tune open-source LLMs for domain tasks and enable explainability.
• Collaborate with data and backend engineers to run scalable workloads.

Skills

RL fundamentals

Production ML systems

Online learning

World models

Fine-tuning LLMs

Distributed training

Python

Education

PhD in CS/OR/Applied Mathematics

Tools

DeepSpeed

FSDP

Megatron-LM

Spark

Ray

Job description

Grab is seeking a Senior Principal Data Scientist to lead automated marketplace optimization. You will design reinforcement learning systems that optimize pricing, dispatch, and supply repositioning, while architecting LLM-based behavioural intelligence at scale.

This role reports to the Head of Data Science and sits in Grab's One-North Singapore office. You will guide a small team, bridging research and production, and work with data engineers to deploy learning-driven solutions that scale