Senior Software Engineer, Backend Platform

About the role

ABOUT HANDSHAKE

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 1,600 educational institutions.

In 2025, we started Handshake AI and built the fastest-growing AI data business in history. We work directly with frontier AI lab researchers to create evaluations, publish benchmarks, and push the boundary of data. We’ve grown from $0 to ~$1B run rate and pay ~$60M to over 30K individuals every month.

Why 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 world’s 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

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.

THE ROLE

Handshake is hiring a Senior Software Engineer to join Backend Platform, with an initial focus on supporting Handshake AI (HAI) and internal AI initiatives.

You will build and maintain backend services, shared platform capabilities, and developer tooling that support HAI and internal AI initiatives. The work centers on core backend platform concerns—service architecture, APIs, data systems, performance, reliability, and developer experience—in an area making increasing use of LLMs and agents.

We are looking for someone who combines strong backend fundamentals with practical knowledge of LLM-powered and agentic systems.

WHAT YOU'LL DO

- Design, build, and operate backend services and APIs that support HAI products and internal AI initiatives, primarily within our full-stack TypeScript repository.

- Develop shared libraries, services, and architectural patterns that reduce duplicated work and make backend systems easier to extend and operate.

- Improve the performance, scalability, reliability, and observability of HAI's backend systems.

- Lead work involving database design, data access patterns, query performance, indexing, caching, and the evolution of data models as products grow.

- Identify recurring product-engineering problems and turn the right ones into reusable platform capabilities and well-understood patterns.

- Make sound architectural decisions across mature systems and new services, balancing delivery speed, performance, maintainability, and operational cost.