Senior Software Engineer, Backend Platform

About the role

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. 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.

Responsibilities

• 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.
• Contribute directly to internal AI initiatives, including shared capabilities used to build, evaluate, and operate LLM-powered and agentic systems.
• Partner with other teams in our Developer Platform group, including ML and Cloud Engineering, on model and service integration, orchestration, evaluation, observability, and failure handling.
• Particip