Senior Backend Engineer (Core, Agents, Learn)

Sana

ABOUT SANA Sana is an AI lab building superintelligence for work. We believe organizations can accomplish their missions faster when teams can effortlessly access knowledge, automate repetitive work, and learn anything with the help of agentic AI. As part of Workday, we are committed to building AI that augments people - not replaces them. We bring this mission to life through two products. Sana Agents provide a seamless way to access all your company’s apps, knowledge, and data, enabling AI agents to do real work so teams can process and act on information at unprecedented scale. Sana Learn is an AI-powered learning hub that combines the simplicity of a modern learning platform with intelligent features like an AI tutor, automated content generation, and interactive apps, making knowledge not just accessible but actionable. We’re a talent-dense, product-obsessed team of engineers and designers from companies like Google, Spotify, Apple, and Databricks, united by deep technical excellence and rapid iteration. Our tools already help over a million people learn and work better across hundreds of leading enterprises - and we’re just getting started. ABOUT THE ROLE You'll build and evolve the core services that power agents and product features, with a focus on enterprise-scale workloads, performance optimization, and long-term architectural sustainability. You drive architecture and systems design to ensure our platform can support high volumes of data, entities, and demanding enterprise clients. IN THIS ROLE, YOU WILL * Design and decompose services and APIs for scale and clarity * Build eventing and queue systems for reliable, high-throughput data flows * Lead schema evolution, migrations, query/index optimization and caching strategies * Define and enforce consistency models and multi-region readiness * Optimize for performance budgets and privacy/tenant isolation * Work hands-on with TypeScript/Node, Postgres, and distributed systems primitives. WHAT SUCCESS LOOKS LIKE * Core services are reliable, scalable, and easy to evolve * Risks are identified and solved before issues become critical * APIs are clear, well-documented, and power seamless product experiences * Data boundaries are robust - privacy and tenant isolation are never compromised * Performance budgets are met, even under heavy load * You are a trusted partner for distributed systems design and implementation OUR TECH STACK We build on a simple modern stack optimized for both humans and AI. * Backend: TypeScript, Kotlin, Node.js * Frontend: TypeScript, React, Tailwind * Databases: Postgres, Redis * Cloud infra: GCP/Kubernetes/Terraform WHAT WE OFFER * Help shape AI's future alongside brilliant minds from Google, Apple, Spotify, Notion, Slack, Databricks, and BCG. * Competitive salary complemented with a competitive RSU program. * Swift professional growth in an evolving environment, supported by a culture of continuous feedback and mentorship from senior leaders. * Work with talented teammates across 5+ countries, and global customers, from our beautiful office in Stockholm.

Workday Sweden Aktiebolag

Sana is an AI lab building superintelligence for work. We believe organizations can accomplish their missions faster when teams can effortlessly access knowledge, automate repetitive work, and learn anything with the help of agentic AI. As part of Workday, we are committed to building AI that augments people - not replaces them. We bring this mission to life through two products. Sana Agents provide a seamless way to access all your company’s apps, knowledge, and data, enabling AI agents to do real work so teams can process and act on information at unprecedented scale. Sana Learn is an AI-powered learning hub that combines the simplicity of a modern learning platform with intelligent features like an AI tutor, automated content generation, and interactive apps, making knowledge not just accessible but actionable. We’re a talent-dense, product-obsessed team of engineers and designers from companies like Google, Spotify, Apple, and Databricks, united by deep technical excellence and rapid iteration. Our tools already help over a million people learn and work better across hundreds of leading enterprises - and we’re just getting started. About the Role You'll build the core agent infrastructure that powers Sana's mission to bring superintelligence to work. This is a greenfield opportunity to define how AI agents plan, reason, and execute across enterprise environments—building systems that reliably handle real-world complexity at scale. You'll work at the intersection of agent architecture, context-, tool- and prompt engineering, and production infrastructure. In this role, you will Architect multi-step planning, orchestration, and tool routing for agents Implement code generation agents and sandboxed code execution Engineer memory, state, and context packing/grounding strategies Balance latency, quality, and cost controls for agent execution Develop safe fallbacks, graceful degradation and robust error handling Collaborate with platform and search teams to deliver reusable agent infrastructure Establish safety guarantees and measurable quality improvements About You Basic Qualifications: 3+ years of software engineering experience building production backend or platform systems. 3+ years of experience in TypeScript, with a strong track record of writing reliable, maintainable services. 3+ years of experience with distributed systems, APIs, asynchronous workflows, and service-oriented architecture. 3+ years of experience designing systems with a focus on scalability, reliability, observability, and maintainability. Other Qualifications: Experience building and deploying LLM-powered applications in production. Experience building agent platforms or AI infrastructure. Deep understanding of the low-level details of the OpenAI, Google, and Anthropic LLM APIs, including tool calling, system prompt caching, etc. Familiarity with LLM application patterns, including tool calling, retrieval-augmented generation (RAG), memory and context management, multi-step orchestration, and human-in-the-loop systems. Experience building and running machine learning systems in production, including compiling training and test datasets, building training pipelines, evaluating models, and detecting and handling drift (neural networks, Gaussian models, Thompson sampling, etc.). Experience designing evaluation frameworks for LLM or agent quality and safety, including hands-on use of platforms such as Langfuse or LangSmith. Familiarity with vector databases, prompt and context engineering, and experimentation tooling. Experience working with sandbox environments such as Modal, and designing strict access control models to keep user data safe and encrypted at all times. Experience running services in Kubernetes-based environments on GCP or equivalent cloud platforms. Comfort working with Postgres and Redis in high-throughput, low-latency service contexts. Contributions to open source TypeScript projects. Ability to navigate ambiguity, make strong technical tradeoffs, and drive projects from concept to production. Strong communication and collaboration skills, with the ability to partner effectively across engineering, product, and AI research teams.

Sana

ABOUT SANA Sana is an AI lab building superintelligence for work. We believe organizations can accomplish their missions faster when teams can effortlessly access knowledge, automate repetitive work, and learn anything with the help of agentic AI. As part of Workday, we are committed to building AI that augments people - not replaces them. We bring this mission to life through two products. Sana Agents provide a seamless way to access all your company’s apps, knowledge, and data, enabling AI agents to do real work so teams can process and act on information at unprecedented scale. Sana Learn is an AI-powered learning hub that combines the simplicity of a modern learning platform with intelligent features like an AI tutor, automated content generation, and interactive apps, making knowledge not just accessible but actionable. We’re a talent-dense, product-obsessed team of engineers and designers from companies like Google, Spotify, Apple, and Databricks, united by deep technical excellence and rapid iteration. Our tools already help over a million people learn and work better across hundreds of leading enterprises - and we’re just getting started. ABOUT THE ROLE You'll build the core agent infrastructure that powers Sana's mission to bring superintelligence to work. This is a greenfield opportunity to define how AI agents plan, reason, and execute across enterprise environments—building systems that reliably handle real-world complexity at scale. You'll work at the intersection of agent architecture, context-, tool- and prompt engineering, and production infrastructure. IN THIS ROLE, YOU WILL * Architect multi-step planning, orchestration, and tool routing for agents * Implement code generation agents and sandboxed code execution * Engineer memory, state, and context packing/grounding strategies * Balance latency, quality, and cost controls for agent execution * Develop safe fallbacks, graceful degradation and robust error handling * Collaborate with platform and search teams to deliver reusable agent infrastructure * Establish safety guarantees and measurable quality improvements WHAT SUCCESS LOOKS LIKE * Agent architectures are robust, reliable, and enterprise-ready * Context and tool engineering enables agents to act intelligently, at scale * Clear metrics, automated evaluation, and continuous improvement in agent capabilities * Quality and safety are measurable and continuously improving * Durable building blocks accelerate product teams and unlock new capabilities OUR TECH STACK We build on a simple modern stack optimized for both humans and AI. * Backend: TypeScript, Kotlin, Node.js * Frontend: TypeScript, React, Tailwind * Databases: Postgres, Redis * Cloud infra: GCP/Kubernetes/Terraform WHAT WE OFFER * Help shape AI's future alongside brilliant minds from Google, Apple, Spotify, Notion, Slack, Databricks, and BCG. * Competitive salary complemented with a competitive RSU program. * Swift professional growth in an evolving environment, supported by a culture of continuous feedback and mentorship from senior leaders. * Work with talented teammates across 5+ countries, and global customers, from our beautiful office in Stockholm.