Software Engineer, API Platform
Horizon3 AI11 hours ago
Remote, United StatesMid Level
Base Salary
$149k - $190k/yr
Responsibilities
- Implement and maintain API endpoints, middleware, and platform services in Go.
- Build and evolve the API gateway layer for routing, authentication, rate limiting, and request/response shaping.
- Write and maintain OpenAPI and gRPC API contracts and communicate breaking changes to internal consumers.
- Contribute to monitoring, alerting, SLA tracking, and incident response for platform APIs.
- Write clear, reviewable code with tests covering happy paths and failure modes.
- Collaborate with Data Ingestion, Integrations Platform, and Client Platform teams that consume the APIs.
Requirements
- At least 2 years of professional software engineering experience building production backend services.
- Proficiency in Go or strong motivation to ramp up quickly; Go is the primary team language.
- Understanding of REST API design principles and HTTP semantics; gRPC experience is a plus.
- Ability to reason about latency, error rates, retry behavior, circuit breaking, and service reliability.
- Comfort working in Kubernetes-based environments, including deploying, debugging, and understanding service interactions.
- Experience with containerized development workflows using Docker.
- Familiarity with OAuth 2.0, API keys, and JWT authentication patterns.
- Clear written communication, meaningful tests, early communication of blockers, and comfort working asynchronously across a distributed team.
- Preferred: experience with Kong, Envoy, NGINX, or cloud-native API gateways; Istio or Linkerd service meshes; cybersecurity APIs; and gRPC or protobuf-defined service contracts.
Benefits
- Fully remote work, with up to 5% travel required; hybrid arrangements and some Chicago office requirements may apply depending on role and location.
- Stock-option equity package for full-time roles.
- Health, vision, and dental insurance for employees and families.
- Flexible vacation policy and generous parental leave.
- Inclusive, collaborative culture with career development opportunities.
Tech Stack
Categories
About Horizon3 AI
Horizon3 AI builds NodeZero, a proactive security platform that autonomously performs penetration testing and validates attack paths across on‑prem, cloud, and hybrid environments. The company sells its software by subscription to security and IT teams at enterprises and government agencies, helping prioritize and verify fixes. Founded in 2019 and headquartered in San Francisco, it is privately held and serves customers across regulated industries and the public sector.