Principal Research Engineer (AI)

TL;DR

Principal Research Engineer (AI): Owning the end-to-end technical stack for offline video generation with an accent on bridging pre-training and post-training stages for large-scale generative models. Focus on driving long-term research strategy, resolving complex technical bottlenecks, and accelerating the delivery of cutting-edge AI research into production.

Location: Remote (Europe)

Company

Synthesia is the world’s leading AI video platform for business, backed by over $530 million in funding and used by 90% of the Fortune 100.

What you will do

• Own the end-to-end technical direction for offline video generation, spanning pre-training and post-training stages.
• Partner with research leadership to define and execute a unified long-term technical roadmap.
• Identify and resolve critical technical gaps in training stability, architecture, and alignment.
• Accelerate the velocity of research-to-product handoffs in collaboration with product managers.
• Coach and elevate junior researchers and engineers through hands-on technical leadership.
• Refine team processes to enable high-velocity, cohesive execution across research initiatives.

Requirements

• Must be based in Europe.
• Proven track record training large-scale generative video models from scratch across multiple nodes.
• Deep experience with post-training techniques at scale, including RLHF, GRPO, and DPO.
• Ability to think strategically about multi-year research direction while remaining hands-on at the frontier.
• Strong cross-functional influence and ability to shape technical direction without positional authority.
• Obsession with shipping research into real-world products.

Culture & Benefits

• Work at the forefront of human-centric avatar video generation.
• Collaborate with a world-class team in a company committed to leading the AI field.
• High-impact role with significant influence over the technical stack and product strategy.
• Opportunity to work with massive compute budgets and proprietary data pipelines.
• Environment that values technical involvement and direct communication.