Founding Applied AI Engineer — Build 0→1 AI Systems

Weekday (YC W21); San Francisco (CA); Hybrid; USD 220,000 - 300,000; Full time

Benefits offered by this job

Medical insurance

Dental insurance

Vision insurance

401(k)

Paid time off

Conferences & learning

Autonomy & ownership

Founders collaboration

Job summary

We are seeking a founding Applied AI Engineer to join Weekday in San Francisco. You will own AI product design and production, partnering with founders to identify high-impact opportunities and deliver 0→1 AI solutions.

With 5+ years in software/ML, you will build scalable AI systems, evaluate models, and shape the technical roadmap while mentoring junior engineers. This on-site/hybrid role offers strong ownership in a fast-moving startup.

Qualifications

• Bachelor's or Master's in CS/AI, or equivalent practical experience.
• 5+ years building software and ML systems.
• Experience deploying production AI applications.

Responsibilities

• Own the design and development of AI-powered products from concept through production.
• Work with founders and product leaders to identify high-impact AI opportunities.
• Build 0→1 AI applications, prototypes, and production systems.
• Design and implement LLM-powered applications, agents, and automation systems.
• Build and optimize RAG pipelines, embeddings, vector search, and context orchestration.
• Evaluate and integrate foundation models from providers or open-source ecosystems.
• Develop prompt engineering, model evaluation, and inference strategies.
• Build robust AI APIs, backend services, and production infrastructure.
• Develop evaluation frameworks to measure model quality, latency, reliability, and cost.
• Improve AI systems through experimentation, data analysis, feedback loops, and iteration.
• Collaborate with product/design teams to translate customer problems into AI experiences.
• Establish engineering best practices around testing, observability, deployment, and AI safety.
• Make architectural decisions enabling AI systems to scale.
• Help establish AI engineering standards, tooling, and technical roadmap.
• Mentor future AI/ML engineers as the team grows.
• Stay current with advances in LLMs, multimodal models, agents, reasoning systems, and applied AI research.

Skills

Python

ML engineering

Distributed systems

CI/CD

Docker

Kubernetes

Git

Problem solving

Communication

Team collaboration

Education

Bachelor's/Master's in CS/AI/Engineering

Tools

FastAPI

Flask

Terraform

PyTorch

LangChain

Job description

We are seeking a founding Applied AI Engineer to join Weekday in San Francisco. You will own AI product design and production, partnering with founders to identify high-impact opportunities and deliver 0→1 AI solutions.

With 5+ years in software/ML, you will build scalable AI systems, evaluate models, and shape the technical roadmap while mentoring junior engineers. This on-site/hybrid role offers strong ownership in a fast-moving startup.