Senior Software Engineer (Annotations)

• We’re looking for a Senior Software Engineer to join our Annotations team and build the systems that power high-quality human data for frontier AI companies
• You’ll work at the intersection of product engineering, distributed systems, and AI data operations—designing tools that help operators manage annotation projects, improve task quality, and scale expert workflows
• This is a high-ownership role in a fast-moving environment
• You’ll partner closely with product, design, data, operations, and engineering teams to turn ambiguous problems into reliable, intuitive software used across the annotation lifecycle
• Build and scale operator tooling that enables teams to create, manage, prioritize, and audit annotation projects
• Design workflows and quality-control systems that improve task accuracy, throughput, and customer outcomes
• Develop performant full-stack features using Python, Node.js/TypeScript, React, PostgreSQL, and backend APIs
• Establish technical direction for complex projects, balancing speed, maintainability, reliability, and operational needs
• Partner with product, design, operations, and data teams to define requirements and ship impactful solutions
• Lead projects from initial concept through high-quality production delivery, including rollout, monitoring, and iteration
• Mentor engineers, raise the quality of code reviews and architecture discussions, and help unblock the team
• Improve engineering processes, testing practices, observability, and operational health across the squad

Benefits

• Health Insurance: Comprehensive medical , dental, and vision coverage
• Fertility and family forming: Through a partnership, Handshake offers comprehensive family benefits, including infertility treatments and a $15K stipend, to its employees.
• LGTBQ+ coverage: All medical plans cover transgender services.
• Mental health: Discounts on a variety of wellness apps and an Employee Assistance Program with access to five free counseling sessions.
• Tax savings: Tax-advantaged benefits to save money on healthcare, dependent care, and other expenses.
• Life & disability insurance: Essential benefits and automatic coverage with basic life insurance, plus short-term and long-term disability coverage.
• 401k match: Dollar-for-dollar match up to 1% of pay, with a max of $1,200 per year.
• Equity: Our equity program includes grants at hire, refresher grants after two years of tenure, and grants alongside promotions.
• Financial management: Handshake partners to provide free professional financial planning services.
• Learning & development: Employees are provided with an annual stipend to use towards professional development, career development workshops, manager trainings, and 1-on-1 coaching through external partnerships
• Community leader support: Employee Resource Group leaders are compensated with a quarterly bonus for the high-impact work the role requires
• Parental leave: Leaves of 16 weeks for birth-giving parents and 10 weeks for non-birth-giving parents; the policy applies to adoptions as well. Handshake also partners to provide one-on-one coaching on preparing for leave and coming back from leave
• Flexible time off: No accrued time off or waiting period to take vacation. Two paid flexible holiday days off to observe holidays that closely align with religious, cultural, and personal needs
• Sabbatical: Paid six-week sabbatical to recharge and reset beginning at six years of continuous, full-time employment, and every four years thereafter
• Volunteer time off: Two days off for social and civil activism, volunteer work, and/or any related activities, including attending and participating in protests

• Strong product judgment and an ability to connect technical decisions to customer and business outcomes
• Comfort working in a high-velocity environment where priorities and requirements evolve quickly
• Excellent communication skills and the ability to work effectively with technical and non-technical partners
• A collaborative leadership style, including experience mentoring engineers and elevating team practices
• Strong proficiency in Python, Node.js, Typescript, React, PostgreSQL, and backend APIs
• 6+ years of software engineering experience building and operating production systems
• Experience designing scalable, reliable software and making sound architectural tradeoffs
• A track record of owning complex projects from ambiguity through delivery
• A quality mindset: you write maintainable code, test thoughtfully, debug deeply, and address root causes
• Experience building workflow, marketplace, operations, or internal-platform software
• Familiarity with AI/ML data pipelines, annotation systems, evaluation workflows, or human-in-the-loop products
• Experience working with distributed teams, expert networks, or high-volume operational processes
• Contributions to open source or a strong record of self-directed technical projects