Senior Applied AI Engineer

Senior Software Engineer | Applied AI | Full-Stack | San Francisco | Startup

Salary: $185K - $220K + equity | Onsite

Location: San Francisco (paid relocation available for candidates currently living elsewhere in the US)

Required Sector Experience: 3 - 6 years of applied AI engineering experience, ideally with multi-agent systems or AI orchestration projects.

🚨Please only apply if you meet this and all of the requirements above and below:🚨

• Candidate must be currently living in the USA and legally able to work.
• Proven experience building reliable AI-enabled systems in production (applied AI, not research).
• Hands-on full-stack experience, delivering features end-to-end in Python, TypeScript, or similar stacks.
• Familiar with multi-agent systems, Langchain or Semantic Kernel, and LLM applications.
• Comfortable working 0→1 in a startup environment, shaping product and engineering practices.
• Strong communication skills and a customer-focused mindset.

The Opportunity

Optimal has partnered exclusively with a stealth-mode startup who is solving the hardest parts of growth marketing using AI. Their platform executes high-quality campaigns at scale, delivering measurable results faster and more reliably than traditional methods.

Well-funded ($15M+) early-stage startup with rapid traction, developing an AI-driven platform that optimises growth marketing at scale, automating complex workflows. Small, high-performing team with ambitious expansion plans.

You’ll join a small, high-caliber engineering team, working across the stack to architect, build, and iterate on AI systems that directly influence customer outcomes.

The Role

• Architect, evaluate, and optimise complex AI/NLP systems end-to-end.
• Build and iterate multi-agent AI architectures in production.
• Collaborate closely with product and design to integrate AI seamlessly.
• Rapidly prototype and deliver features with high reliability and quality.
• Work across frontend (React/NextJS/TypeScript) and backend (Python, C#, Postgres) as needed.
• Shape engineering culture in a fast-moving, early-stage team.

Who We’re Looking For

• 2–6 years experience in applied AI with strong understanding of LLM capabilities and limitations.

Discover our full range of relocation jobs with comprehensive support packages to help you relocate and settle in your new location.

• Experience building multi-agent systems or AI orchestration pipelines.
• Hands-on full-stack experience: Python backend, React/TypeScript frontend, GraphQL, and cloud deployment (Google Cloud).
• Thrives in ambiguity, ownership, and fast-paced early-stage environments.
• Passionate about quality-first engineering, building reliable and scalable AI products.
• Computer Science degree preferred

Why This Role

• Cutting-edge AI work: Build AI systems that deliver outcomes at scale, not just demos.
• Well-funded and high-growth: $15M+ raised, with rapid traction and ambitious expansion plans.
• First-mover advantage: Be part of the first team automating complex marketing workflows with AI.
• In-person culture & flexibility: Energetic San Francisco office with paid relocation for US-based candidates.
• Quality-focused engineering: Work in a team that values reliability, craftsmanship, and impact.
• Great benefits package: Competitive salary, equity, unlimited PTO, offsites, health coverage, and education stipends.

If this sounds like you and you want to be part of something special, reach out to us for a prompt response.