Staff Fullstack Engineer

Overview

Lead the technical direction of the team that builds Alpaca's Trading API product, owning the customer experience end to end across customer-facing trading applications, identity, account and permission systems, and partner and AI agent integrations. You will remain a principal contributor and lead through architecture, code, design reviews and mentorship.

What you'll do

• Own the architecture and technical roadmap for how customers access and use Trading API: identity and authentication, authorization and permissions, account and sub-account models, partner OAuth, and customer-facing trading and account-management applications.
• Design the access model for increasingly complex account structures, including multiple users per account, sub-accounts, entity and advisor accounts, and delegated API and agent access, so that permissions are explicit, auditable, and enforced on the server.
• Lead technical delivery of next-generation Trading API customer applications, including real-time market data, order entry, and positions and order views, as the product expands to new customer surfaces.
• Drive the move from legacy monolith endpoints to a dedicated application backend, with clear API contracts between customer applications and platform services such as trading, accounts, transfers, ledger, and market data.
• Set the security bar for customer-facing systems: session and credential handling, MFA and passkeys, OAuth flows, rate limiting, input validation, and fast, durable responses to security findings.
• Set the standard for safe delivery: feature flags, staged rollouts, preview environments, testing strategy, and production observability.
• Partner with Product, Design, Compliance, Security, Brokerage Operations, and adjacent engineering teams to define behaviour and integration boundaries.
• Lead design reviews, mentor senior and mid-level engineers, and raise the engineering bar as the team grows.
• Act as a technical point of escalation for production issues on customer-facing Trading API systems, and drive durable prevention after incidents.

What you'll need

• 8+ years of software engineering experience, with significant time on both backend services and customer-facing applications (evidence of scope and ownership matters more than a strict year count).
• Proven ownership of a production system where a defect could expose customer data, grant the wrong access, or cause financial loss.
• Deep experience with authentication and authorization: OAuth 2.0 and OpenID Connect, session and token management, MFA, and role- or attribute-based permission models.
• Strong backend expertise in Go, or deep experience in Java, Kotlin, C#, or Rust and a clear willingness to work primarily in Go.
• Strong frontend experience with TypeScript and React, including complex, state-heavy applications.
• Solid knowledge of relational databases (PostgreSQL preferred), API design (REST and gRPC), and service-oriented systems running on Kubernetes.
• Demonstrated care for correctness and security: threat modelling, testing strategy, edge-case analysis, and safe production rollout.
• Clear communication with engineers, designers, product managers, and compliance and security partners, including when requirements are ambiguous or still being defined.
• Track record of technical leadership and mentorship across teams.
• Product-minded: you care what the customer sees and why, and you are effective as a teammate.

Nice to have

• Experience with real-time data over WebSockets or other streaming protocols.
• Experience building trading, brokerage, or other financial applications: order entry, positions and P&L, charting, or real-time market data.
• Experience with identity platforms or building identity in-house (for example, Amazon Cognito, Keycloak, or Auth0), passkeys and WebAuthn, or delegated access for third-party applications.
• Experience with API platforms and developer products: API keys, scopes, rate limits, SDKs, or developer dashboards.
• Experience with agentic AI integrations, such as MCP servers or tooling that lets AI agents act safely on a user's behalf.
• Familiarity with FIX or institutional trading workflows.
• Experience leading migrations off a legacy monolith in production-critical environments.

Details

• Location: Remote, Americas or EU.
• Individual contributor role with no direct people management.
• Benefits include competitive salary and stock options, health benefits, a one-time USD $500 new hire home-office setup, and a USD $150 monthly stipend via a Brex Card.