AI Engineer

Title: AI Engineer Location: San Mateo, CA

Overview of the Role:

Advertising is being rebuilt for a world where AI agents plan, buy, and create the ads, and InMobi is building for that world now. As an AI Engineer, you'll build the harnesses, agents, and fine-tuned models that bring generative AI into our products and internal workflows.

You'll work across the full stack of modern GenAI systems: designing agent harnesses, fine-tuning LLMs and diffusion models with RL, building evaluations, and optimizing systems both with and without training.

This isn't a roadmap item. AI buying agents already purchase our inventory through AdCP – the Ad Context Protocol. Our own agents build complete campaigns, creatives included. And inside the company, agents write, review, and ship code, build their own tools, and run customer success, ad quality, and cloud cost management.

We've built the foundation to push further, with GPU capacity to train and serve our own models and an AI gateway that handles model traffic for every team. If you want to own hard problems from first idea to production, there’s no shortage of them here!

Location: This role is based on-site at our San Mateo, CA office location.

The Impact You'll Make:

• Autonomous creative generation: Build a system that turns brand guidelines into ad creatives, then keeps improving them from live campaign performance.
• ML research agent: Build an agent that speeds up ML research for our Applied Scientists.
• Learning from real-world signals: Turn signals such as creative performance and developer feedback into training data, so our systems keep getting better after launch.
• End-to-end ownership: Own projects from framing the problem and defining success through shipping and iterating in production.
• Evals and measurement: Define what “good” looks like for systems without an obvious metric, and build the evals and annotation processes to measure it.
• Open-source contribution: Build on and contribute to the open-source tools shaping this space, including training frameworks like LLaMA-Factory and verl and agent harnesses like opencode and OpenResearch.
• Cross-team partnership: Partner with Applied Scientists, Product, and Engineering to turn promising prototypes into production systems.

The Experience We Need:

Required

• 2+ years of experience building GenAI systems in production.
• A solid grasp of LLM and diffusion model architectures.
• Expertise in building agents and agent harnesses.
• A track record of designing evals from scratch, including writing labeling guidelines and working with annotators.
• Hands-on experience fine-tuning LLMs or diffusion models with RL techniques (for example, PPO, GRPO) or preference optimization methods like DPO.
• Experience building knowledge retrieval systems, including ANN-based and knowledge-graph-based retrieval.
• Experience with no-train optimization techniques and frameworks like DSPy.
• Expertise in Python.
• A Bachelor’s or Master’s degree in Computer Science, Machine Learning, or a related field, or equivalent practical experience.

Nice to Have

• Understanding of the ads ecosystem (OpenRTB, SSPs, DSPs, ad exchanges, MMPs).
• Contributions to open-source GenAI projects, such as LLaMA-Factory, verl, opencode, or OpenResearch.
• Public work in LLMs, diffusion models, reinforcement learning, or agents, such as publications, write-ups, or talks.
• Experience with large-scale GPU training and serving, including distributed training and inference optimization.
• Experience building coding agents or developer tools that write, review, or ship code.

At InMobi, you’ll be surrounded by people who…

• Think big and act fast: We’re entrepreneurial, thrive in ambiguity, and love solving high-impact problems
• Are passionate, fanatically driven, and take immense pride in their work: We care deeply about the impact we create and continuously push our potential
• Own their outcomes: We take responsibility, make bold decisions, and execute with confidence
• Embrace freedom with accountability: We value autonomy and understand that trust comes with responsibility
• Believe in lifelong learning: We welcome feedback, challenge ourselves to grow, and aren’t afraid to take smart risks

Award-winning culture, best-in-class benefits

Our compensation philosophy enables us to provide a competitive salary that drives high performance while balancing business needs and pay parity. We determine compensation based on a wide variety of factors, including role, nature of experience, skills, and location.

The base salary (fixed) for this role ranges from $178,500 to $222,000 USD (min to max of base salary). This salary range is applicable to our offices located in California and New York*.

Our ranges may vary based on the final location or region of the roles in accordance with the geographical differentiation in pay scales in the country.

In addition to cash compensation, based on the position, an InMobian can receive equity in the form of ESOPs (Employee Stock Option Plan). We believe that our employees/personnel should have the ability to own a part of the entity they are a part of. Therefore, the entity employing you may elect to provide such stock to you. Ownership of stock enables us to treat our employer company as our own and base our decisions on the company’s best interests. To encourage a spirit of shared ownership, we grant InMobians relevant company stock(s). As you contribute to the growth of your company, certain stocks may be issued to you in recognition of your contribution.

A quick snapshot of our U.S. benefits:

• Competitive salary and ESOP grant (where applicable)
• High-quality medical, dental, and vision insurance (including company-matched HSA)
• 401(k) company match
• Generous combination of vacation time, sick days, special occasion time, and company-wide holidays
• Substantial maternity and paternity leave benefits and a compassionate work environment
• Flexible working hours to suit everyone
• Wellness stipend for a healthier you!
• Free lunch is provided in our offices daily
• Pet-friendly work environment and robust pet insurance policy - because we love our animals!
• Employee Assistance Program (EAP)

If this sounds like the kind of team, role, values, benefits, and challenges that excite you, we’d love to hear from you. Go for it!

InMobi is an equal opportunity employer

InMobi is a place where everyone can grow. Howsoever you identify, and whatever background you bring with you, we invite you to apply if this sounds like a role that would make you excited to work. 

InMobi provides equal employment opportunities to all employees and applicants for employment and prohibits discrimination and harassment of any type.  All qualified applicants will receive consideration for employment without regard to race, color, religion, age, sex, national origin, disability status, genetics, protected veteran status, sexual orientation, gender identity or expression, or any other characteristic protected by federal, state, or local laws. This policy applies to all terms and conditions of employment, including recruiting, hiring, placement, promotion, termination, layoff, recall, transfer, leaves of absence, compensation, and training.