Software Engineer, Foundations

Hex is hiring a Senior Backend Software Engineer for its Foundations team. The role is mostly backend work: designing and evolving the shared systems other engineering teams build on. It is for someone with at least five years of professional software engineering experience and a strong backend focus, who is comfortable owning production systems over time.

The Foundations team owns the application-level infrastructure behind Hex: shared backend systems, frameworks, and primitives. Work spans APIs, realtime transport, storage frameworks, background processing, and internal tooling. The team focuses on durable systems rather than isolated features.

What you will do

• Design and build backend frameworks and services used across the company
• Own and evolve shared systems, including APIs, realtime transport, and job orchestration
• Improve reliability, performance, observability, and security of foundational backend infrastructure
• Partner with product teams to turn recurring needs into shared abstractions
• Lead technical design discussions and help set architectural direction
• Drive refactors, migrations, and system upgrades that reduce long-term complexity
• Improve internal tooling for debugging, operations, and customer-facing workflows
• Mentor other engineers and contribute to engineering standards and practices

Areas you will contribute to

• APIs: GraphQL schema design, performance, and developer ergonomics; authentication and authorization; multiplayer and collaboration APIs covering realtime state and concurrency
• Transport: WebSockets and realtime communication infrastructure
• Storage frameworks: Postgres schema design, query optimization, and migrations; S3, DynamoDB, Redis
• Job and workflow systems: BullMQ and background job processing; Temporal or similar workflow orchestration
• Internal tooling: admin tools for debugging, operations, and customer support

What they are looking for

• 5+ years of professional software engineering experience with a strong backend focus
• Experience with Typescript/Node.js and SQL
• Experience building and maintaining shared backend systems or frameworks used by multiple teams
• Strong understanding of API design, distributed systems, and asynchronous workflows
• Experience with relational databases and data modeling at scale
• Familiarity with background job systems, queues, or workflow orchestration tools
• Comfort operating and evolving production systems over time
• Experience with cloud infrastructure (AWS preferred)
• Strong communication skills and a collaborative, leverage-oriented mindset

Bonus points

• Experience with Python
• Hands-on experience with GraphQL, WebSockets, BullMQ, or Temporal
• Familiarity with observability tooling (metrics, tracing, logging)
• Background in data platforms, developer tools, or collaborative systems
• Experience with frontend technologies such as React and TypeScript for end-to-end context
• Open-source contributions, especially in backend or infrastructure projects

The stack

Hex is a web-based notebook and app authoring platform. The frontend uses TypeScript and React with Apollo GraphQL and Redux. The backend uses TypeScript for an Express/Apollo GraphQL server that interacts with Postgres, Redis, and Kubernetes to manage the database and Python kernels. Backend work is integrated with infrastructure and CI/CD using Terraform, Helm, and AWS.

Pay and benefits

The salary range for this role is $215,000 to $270,000 per year. Hex offers market-benched salary and equity, health benefits, and flexible paid time off. The posted range may reflect factors such as geographical location and the skill levels they are open to. Placement in the range is decided after the interview process, considering factors like room for growth, internal fairness and parity, demonstrated skills, and depth of experience.

Hex uses AI-assisted tools in application review, including resume screening and fraud detection. AI-generated recommendations are reviewed by a recruiting team member before any hiring decision, and no application is automatically rejected based solely on an AI tool's output.