Member of Technical Staff - Fullstack AI Engineer

Solstice is seeking a Fullstack AI Engineer to build and maintain an agent platform and integrate agent capabilities into the product. This role combines backend and frontend delivery, with a strong emphasis on Python, platform engineering, and agent execution.

What You Will Do

• Build and maintain the agent platform.
• Design APIs that power the product.
• Solve complex aspects of agent execution.
• Bring AI workflows into the product experience.
• Make the end-to-end system observable.
• Make system quality measurable.
• Own the full path from idea through production.

Core Requirements

• Strong depth in Python and FastAPI, including production Python services that have been shipped and operated.
• Ability to build well-designed FastAPI APIs and understanding of asynchronous programming, validation, authentication, and error handling.
• Solid systems fundamentals, including clear service contracts and data model design.
• Comfort working with PostgreSQL and Redis.
• Experience reasoning through concurrency, transactions, idempotency, and failure recovery.
• Experience turning AI into useful software, including tool calling, context management, agent sessions, and boundaries between model behavior and application logic.
• Ability to deliver across the stack, including working with React, Next.js, and TypeScript and connecting interfaces to backend APIs.
• Care for product experience, including usability, accessibility, and performance.
• A habit of making systems understandable using traces, logs, metrics, and instrumentation to investigate production issues.
• Testing, security, and maintainability are part of how you ship.
• Ownership and good judgment, including turning ambiguous problems into practical plans and following through.
• Ability to explain tradeoffs and focus on solving the customer’s problem.

Technologies

• Python, FastAPI
• React, Next.js, TypeScript
• Restate
• Redis, PostgreSQL
• Datadog, OpenTelemetry
• OpenTelemetry tracing, structured logs, metrics, alerts
• Braintrust
• Asynchronous programming, authentication

Ideal Additional Experience

• Experience with Restate or Temporal.
• Experience with sandboxed agent execution, streaming systems, or AI evaluation tools.
• Healthcare or pharma experience is welcome but not required.
• Not required to have experience with every tool in the stack.

Compensation and Location

Location: New York, NY (onsite).
Compensation: USD 200,000 to 300,000 per year, plus equity.

Benefits

• Medical, dental, and vision coverage
• Equity in an early-stage company
• Unlimited paid time off
• 401(k) with a 4% employer match
• Company-provided office lunches five days a week
• Stipend for professional development
• Relocation assistance
• Sponsorship for O-1, H-1B, and TN visas

Role Scope

This position covers backend services, APIs, agent orchestration, and customer-facing interfaces. Python is the primary backend language, and FastAPI powers the APIs. The work includes helping decide how agents run, how they recover from failures, how they access tools and context, and how execution communicates with the application. It also includes building the React and Next.js experiences that provide users with visibility and control over agent work.

Collaboration

You will partner with product, design, Applied AI, and the broader engineering team to take problems from initial idea through architecture, implementation, and production. The scope includes building new capabilities while also improving the systems behind them so they are easier to operate and extend.