Senior Software Engineer, Annotations — Build AI Data Workflows

Handshake; San Francisco (CA); On-site; USD 180,000 - 240,000; Full time

Benefits offered by this job

Equity in a fast-growing company

401(k) match

Medical, dental, and vision coverage

Wellness stipend

Parental leave and coaching

Learning stipend

Flexible PTO

2 flex days

Internet and commuting support

Gym access

Job summary

Handshake is hiring a Senior Software Engineer for the Annotations team to build systems powering high-quality human data for frontier AI companies. You will work at the intersection of product engineering, distributed systems, and AI data operations, designing tools to manage annotation projects and scale expert workflows.

This high-ownership role collaborates with product, design, data, operations, and engineering to turn ambiguous problems into reliable, intuitive software across the

Qualifications

• 6+ years of software engineering experience building and operating production systems.
• Strong proficiency in Python, Node.js, Typescript, React, PostgreSQL, and backend APIs.
• Experience designing scalable, reliable software and making sound architectural tradeoffs.
• A track record of owning complex projects from ambiguity through delivery.
• Strong product judgment and an ability to connect technical decisions to customer and business outcomes.
• Excellent communication skills and the ability to work effectively with technical and non-technical partners.
• A quality mindset: maintainable code, thoughtful testing, deep debugging, root-cause analysis.
• A collaborative leadership style with mentoring experience.

Responsibilities

• Build and scale operator tooling to create, manage, prioritize, and audit annotation projects.
• Design workflows and quality-control systems to improve task accuracy and throughput.
• Develop performant full-stack features using Python, Node.js/TypeScript, React, PostgreSQL, and APIs.
• Establish technical direction balancing speed, maintainability, and reliability.
• Partner with product, design, operations, and data teams to define requirements and ship solutions.
• Lead projects from concept through production delivery, including rollout and monitoring.
• Mentor engineers and raise quality of code reviews and architecture discussions.
• Improve engineering processes, testing, observability, and operational health.

Skills

Python

Node.js

TypeScript

React

PostgreSQL

Backend APIs

Distributed systems

Mentoring

Communication

Job description

Handshake is hiring a Senior Software Engineer for the Annotations team to build systems powering high-quality human data for frontier AI companies. You will work at the intersection of product engineering, distributed systems, and AI data operations, designing tools to manage annotation projects and scale expert workflows.

This high-ownership role collaborates with product, design, data, operations, and engineering to turn ambiguous problems into reliable, intuitive software across the