Senior Software Engineer, Backend Platform

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 1600 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. Weve 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 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

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 concernsservice architecture APIs data systems performance reliability and developer experiencein 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 youll 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 HAIs 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.

• Participate in technical planning design and code reviews operational support and incident response.

• Mentor other engineers and help establish practical backend engineering standards across HAI and internal AI initiatives.

You Have

• 5 years of professional software engineering experience primarily in backend or platform engineering.

• Experience designing building and operating production services and APIs.

• Strong understanding of distributed systems data modeling service boundaries common backend architecture patterns and reliability and performance tradeoffs.

• We strongly prefer candidates with deep TypeScript and experience. Because this work is primarily based in a full-stack TypeScript repository you should be comfortable navigating the broader application and contributing across boundaries when necessary.

• Strong experience with relational databases including schema design query optimization indexing transactions and diagnosing database-related performance problems. Experience with PostgreSQL is especially relevant.

• Familiarity with backend technologies such as Temporal Redis Elasticsearch GraphQL or event-driven systems.

• Experience operating services in cloud and containerized environments. Our broader platform uses technologies including GCP Kubernetes Terraform and Docker.

• Practical knowledge of LLM-powered systems including concepts such as model and tool integration RAG agent orchestration prompt management evaluation and observability.

• A record of independently driving ambiguous projects from problem definition through production rollout.

• Strong communication skills and the ability to collaborate with product engineers and other teams across Developer Platform.

• Sound technical judgment and a preference for understandable maintainable systems over unnecessary complexity.

Bonus points

• Direct production experience with product features powered by ML LLMs or agents.

• Experience with LLM orchestration frameworks or agent architectures involving tool use memory and multi-step workflows.

• Experience building internal AI tools or shared AI capabilities used by other engineers.

• Experience creating internal platforms paved paths or self-service tools used by other engineers.

• Experience modernizing mature backend systems while continuing to support active product development.

• Experience with event-driven architecture or high-throughput data systems.

How we think about this role

This is a backend platform role supporting HAI and internal AI initiatives. The strongest candidates will bring TypeScript and depth alongside experience in backend architecture databases and performance plus enough practical AI knowledge to contribute directly to this work. Success does not require expertise in every model or framework but it does require the ability to design and operate the systems around AI-powered product experiences.

We Offer

Handshake delivers benefits that help you feel supported and thrive at work and in life.

The below benefits are for full-time US employees.

Ownership: Equity in a fast-growing company

Financial Wellness: 401(k) match competitive compensation financial coaching

Family Support: Paid parental leave fertility benefits parental coaching

Wellbeing: Medical dental & vision mental health support $500 wellness stipend

Growth: $2000 learning stipend ongoing development

Remote & Office: Internet commuting & free lunch/gym in our SF office

Time Off: Flexible PTO 15 holidays 2 flex days

Connection: Team outings & referral bonuses

Explore our mission values & comprehensive US benefits at Experience:

Senior IC