Senior Software Engineer, LLM 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.

Handshake is hiring a Senior LLM Platform Engineer to join our Data and ML Platform team. This team supports Handshakes core career marketplace and Handshake AI (HAI) by building the shared data ML and LLM infrastructure behind production workflows.

This infrastructure-heavy role primarily owns our shared LLM control plane: LiteLLM gateways provider integrations shared clients access controls observability cost attribution capacity management and hosted or self-hosted inference. Youll also contribute to adjacent platform systems for workflow orchestration model serving shared cloud infrastructure and developer enablementworking closely with Backend Platform HAI engineering data science and FDEs.

What Youll Do

• Build and operate our LiteLLM-based AI gateways and shared LLM clients.

• Own provider and model onboarding routing failover rate limits and capacity planning.

• Build self-service virtual-key model-access budget and credential-management workflows.

• Establish SLOs observability cost attribution and alerts for production LLM traffic.

• Safely qualify and roll out new models providers SDKs and gateway configurations.

• Support hosted and self-hosted inference through a consistent platform interface.

• Partner with product AI and FDE teams to turn recurring delivery problems into paved-platform capabilities.

• Contribute to the broader Data and ML Platform including workflow orchestration model serving shared cloud infrastructure and developer tooling.

• Participate in team on-call and support improving runbooks automation and reliability across owned platform services.

What Were Looking For

• Strong production software engineering experience in Python TypeScript Go or a similar language.

• Experience building or operating high-throughput API gateways proxies or multi-tenant platform services.

• Hands-on experience with Kubernetes Terraform CI/CD and production service ownership.

• Practical experience with LLM provider APIs including streaming long-running requests retries timeouts cancellation and rate limits.

• Experience with authentication quotas credential management tenant isolation and auditability.

• Experience building observability for distributed systems and leading production incident response.

• Experience with usage metering cost attribution capacity planning or FinOps.

• Experience with data or ML platform systems such as BigQuery Airflow streaming pipelines model serving or ML observability.

• Strong judgment in ambiguous environments and a bias toward simple reliable systems that scale.

Bonus Experience

• LiteLLM Portkey or a comparable multi-provider AI gateway.

• vLLM Modal Ray Triton PyTorch or GPU-backed serving.

• Temporal or another durable-execution system for long-running LLM requests.

• Evaluation batch inference fine-tuning RL or other post-training infrastructure.

• Agent runtimes sandbox infrastructure MCP tool use or coding-agent infrastructure.

Our Stack

Python TypeScript Go LiteLLM FastAPI PostgreSQL Redis GCP Kubernetes Terraform Spacelift BigQuery Airflow Dataflow/Beam Datastream OpenAI Anthropic Gemini OpenRouter vLLM Modal Anyscale/Ray Datadog Arize Temporal Cloudflare and Tailscale

Perks

Handshake delivers benefits that help you feel supportedand 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 and vision mental health support $500 wellness stipend

Growth: $2000 learning stipend ongoing development

Remote & Office: Internet commuting and 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 and comprehensive US benefits at Experience:

Senior IC