Senior Principal Data Scientist (Fulfilment)

Grab is Southeast Asia's leading superapp, providing various services such as food delivery, financial management, and transportation.

As Senior Principal Data Scientist, you will be the senior individual contributor lead architecting Grab's next generation of autonomous marketplace decisioning systems.

The Fulfilment Tech Family builds distributed systems and machine learning platforms that power Grab's multi-sided marketplace across Southeast Asia.

The Critical Tasks You Will Perform:

• Architect and implement end-to-end reinforcement learning pipelines (offline RL, model-based RL, and simulation) to jointly automate pricing, dispatch, and supply repositioning decisions.
• Design latent world models and spatio-temporal marketplace state representations that capture complex supply-demand interactions and multi-temporal levers.
• Establish formal off-policy evaluation (OPE) frameworks, conservative value estimation baselines, and safety guardrails to de-risk live deployment in production.
• Build behavioural simulation systems using fine-tuned open-source large language models (LLMs) to forecast and simulate user and partner decision dynamics.
• Partner with backend, streaming, and platform engineering teams to deploy low-latency, closed-loop decision agents into high-throughput production environments.
• Leverage modern Generative AI development tools and AI-assisted workflows to accelerate prototyping, code quality, testing, and technical documentation across the team.

QUALIFICATIONS:

• You have a PhD in Computer Science, Operations Research, Applied Mathematics, or a related quantitative discipline with at least 10 years of post-degree experience leading complex machine learning research and production initiatives (or Master's degree with at least 12 years of equivalent experience).
• You are proficient in reinforcement learning foundations, including Markov Decision Processes, stochastic control, offline RL, and reward shaping for sequential multi-objective decision systems.
• You have proven experience deploying production ML/RL systems operating under real-time constraints, non-stationary data, and distribution shifts.
• You have hands-on expertise with large language model adaptation and alignment, including supervised fine-tuning (SFT), parameter-efficient methods (LoRA/QLoRA), and preference tuning (RLHF, DPO, or GRPO).
• You have hands-on proficiency in Python, PyTorch, and distributed training/compute platforms such as Ray, DeepSpeed, FSDP, or Megatron-LM.
• You have experience engaging with AI tools and emerging technologies to enhance productivity, improve workflows, and contribute new ideas.

Life at Grab:

• We have your back with Term Life Insurance and comprehensive Medical Insurance.
• With GrabFlex, create a benefits package that suits your needs and aspirations.
• Celebrate moments that matter in life with loved ones through Parental and Birthday leave, and give back to your communities through Love-all-Serve-all (LASA) volunteering leave
• We have a confidential Grabber Assistance Programme to guide and uplift you and your loved ones through life's challenges.
• Balancing personal commitments and life's demands are made easier with our FlexWork arrangements such as differentiated hours