Senior REST API Developer for GraphQL Endpoint Build

Keystone Digital

Freelance · Remote · Flexible hours

About the role

Keystone Digital is revamping a legacy production platform that must stay online 24/7. We need a REST API Developer to redesign critical services, enforce zero‑downtime deployments, and improve performance while preserving existing integrations.

Key responsibilities

• Refactor legacy endpoints into clean, versioned REST APIs
• Implement blue‑green and canary release strategies for zero‑downtime rollout
• Design and optimize PostgreSQL schemas and queries for high‑throughput workloads
• Write comprehensive unit and integration tests using modern JavaScript frameworks
• Collaborate with DevOps to automate CI/CD pipelines and monitor service health

Must-have skills

• 5+ years building and scaling RESTful services
• Expertise in NodeJS and JavaScript (ES6+)
• Strong SQL proficiency with PostgreSQL
• Experience with zero‑downtime deployment patterns
• Ability to produce clear documentation and API contracts

Nice to have

• Familiarity with Docker and Kubernetes
• Knowledge of API gateway solutions (e.g., Kong, Ambassador)
• Background in legacy system migration projects