Staff Machine Learning Engineer, Ads Creative Effectiveness

About the Role

Reddit’s Ads Creative Effectiveness team sits at the heart of our creative strategy, building GenAI and predictive products that help advertisers ship high-impact campaigns. We are searching for a Staff engineer with in-depth GenAI expertise that can help us build the future of generative products for ad creative at Reddit - best-in-class image, video and copy generators that leverage Reddit’s best practices, performance-guided generations that maximize clicks and conversions, and brand safe, product preserving image/video editing pipelines.

What you’ll do:

• Advanced Generative Workflows: Architect and implement state-of-the-art pipelines for ad creative generation. You will move beyond vanilla prompting to build systems capable of product, font, logo and brand asset preservation using techniques like IP-Adapters, and LoRAs.
• End-to-End Image & Video Editing: Build editing capabilities allowing advertisers to smart-crop, inpaint, outpaint, resize, and style-transfer assets while maintaining strict brand guidelines.
• LLM/VLM Fine-Tuning: Adapt large vision-language models to understand "winning" ad aesthetics. You will build feedback loops where ad performance metrics (CTR, CVR) are used to fine-tune the generation process (RLHF/RLPF for Ads).
• Safety & Compliance Layer: engineer robust filtering and safety systems. You ensure our models never generate non-compliant, unsafe, or copyright-infringing content.
• Partner Broadly: Collaborate with Product, Sales, Policy, UX, and sibling Ads ML teams to integrate ACE capabilities into the Ad Manager UI and the ad delivery path.
• Guardrails & Safety: Embed brand-safety filters, copyright checks, and human-in-the-loop escalation paths to protect users and advertisers.

What we’re looking for:

• Deep ML Expertise: Hands-on experience with tree models, neural nets, ranking, and especially LLM/VLM fine-tuning & RLHF/RLPF for ads.
• Quant & Experimentation Chops: Comfort with uplift metrics, variance, minimum detectable effects and experimentation setups for generative systems.
• Ads / Marketplace Insight: Understanding auction dynamics and advertiser pain points to create tools that drive revenue and retention.
• Startup Mindset: Bias to action, comfort with ambiguity, and scrappiness: ACE evolved from a startup acquisition and still moves fast.
• Communication Superpowers: Able to distill complex ML trade-offs for executives, product managers, and non-technical stakeholders alike.
• Prior work on ad creative tooling