Formula5 is seeking a contract Java Developer to support a 6-8 week engagement delivering a HubSpot-to-Microsoft Entra External ID integration. The senior developer will build a Java Spring Boot microservice deployed on Client's Kubernetes infrastructure, enabling event-driven user provisioning and lifecycle management between HubSpot (system of record) and Entra External ID via Microsoft Graph.
Required Skills & Experience
Java / Spring Boot - Production-grade microservice development; this is the core of the engagement
REST API development - Designing and implementing Create/Update/Disable endpoints; Swagger/OpenAPI documentation
Webhook integration - Building and securing inbound webhook receivers (HubSpot webhooks specifically)
Microsoft Graph API - Entra External ID user provisioning and lifecycle management (create, update, disable)
Docker - Containerization, Dockerfile authoring, Docker Compose for local dev environments
Kubernetes - Deployment artifact creation (manifests or Helm); familiarity with Argo CD a plus
CI/CD - GitHub Actions for build/packaging pipelines
Observability tooling - Loki log exporter configuration; Grafana/Prometheus familiarity
Security patterns - Service-to-service authentication, secrets management (API keys, Graph credentials), WAF/API gateway awareness (Imperva, Tyke)
Nice to Have
Experience with HubSpot API - Contact management operations (create/update/disable, query by CompanyID)
Experience with Microsoft Entra External ID / Azure AD B2C
Familiarity with React + Java backend portal integrations
Prior work in regulated financial services environments