Senior Software Engineer, Annotations

Handshake was founded on a simple belief that everyone deserves a path to a great career regardless of where they went to school or who they know. Today we power 25 million job seekers 1 million employers and 1600 educational institutions.

About Handshake AI

Human data is the core infrastructure to AI advancement. Frontier AI labs currently improve model capabilities with various data-intensive post-training techniques. We believe that data spend for AI training will increase by 3-5x in the next few years and continue for much longer as models take on new domains. Handshake AI supports all of the frontier AI labs working on their most complex data at the largest scale.

Were 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. Youll work at the intersection of product engineering distributed systems and AI data operationsdesigning 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. Youll 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 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.

• 6 years of software engineering experience building and operating production systems.

• Strong proficiency in Python 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: you write maintainable code test thoughtfully debug deeply and address root causes.

• A collaborative leadership style including experience mentoring engineers and elevating team practices.

• Comfort working in a high-velocity environment where priorities and requirements evolve quickly.

• 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.

Handshake delivers benefits that help you feel supported and thrive at work and in life. Benefits for full-time US employees include:

• Equity in a fast-growing company

• 401(k) match competitive compensation and financial coaching

• Medical dental and vision coverage

• Mental health support and a $500 wellness stipend

• Paid parental leave fertility benefits and parental coaching

• $2000 annual learning stipend

• Flexible PTO 15 holidays and 2 flex days

• Internet commuting support and free lunch and gym access in our San Francisco office

• Team outings and referral bonuses

Explore our mission values and comprehensive US benefits at join Handshake now:

• Shape how every career evolves in the AI economy at global scale with impact your friends family and peers can see and feel

• Partner hand-in-hand with world-class AI labs Fortune 500 partners and the worlds top educational institutions

• Work together with engineers scientists operators and more from Palantir Meta Scale AI and former YC founders

• Build a massive fast-growing business with billions in revenue

Required Experience:

Senior IC