Principal Research Engineer

Synthesia is seeking a Principal Research Engineer to own the full technical stack for offline video generation. As a senior individual contributor, you will partner directly with research leadership and team leads to define long-term strategy, resolve the hardest cross-cutting technical problems, and raise the bar for how quickly research reaches product.

You will own the end-to-end technical direction for offline video generation, spanning pre-training and post-training, resolving the artificial boundary between those two stages in service of shipping better models faster.

Key responsibilities include:

• Partnering with research leadership and team leads to define a unified long-term roadmap, broken into achievable objectives, and drive execution against it.

• Identifying the most critical technical gaps across the video generation pipeline and jumping in to unblock them, whether that means architectural decisions, training stability, post-training alignment, or cross-team coordination.

• Increasing the velocity at which research ships to product: accelerating problem-solving, improving research-to-production handoffs, and increasing visibility of research output in partnership with PMs.

• Coaching and elevating more junior researchers and engineers toward senior technical thinking and execution.

• Helping shape team structure and refining processes to enable high-velocity, cohesive execution across research.

To succeed in this role, you will need to have a proven track record training large-scale video generation models from scratch, deep experience with post-training techniques at scale, and the ability to think strategically about multi-year research direction and execute hands-on at the frontier of what the team is building.

In particular, relevant experience includes having owned a major model generation or capability jump end-to-end, working across both pre-training and post-training stages on the same model family, and applying alignment and fine-tuning techniques in a video or multimodal context.