Senior Golang Engineer (GraphQL)

TL;DR

Senior Golang Engineer (GraphQL): Building and optimizing the Cosmo Router, an open-source GraphQL Federation solution, with an accent on high-performance Go code and AST transformations. Focus on implementing new data sources (gRPC, SOAP), optimizing batching, and ensuring low GC overhead for maximum router efficiency.

Location: Remote (EMEA), must be able to work within the CET time zone

Salary: €80K – €100K

Company

A fast-growing startup building an open-source GraphQL Federation platform to streamline API environments.

What you will do

• Develop and maintain the Cosmo Router open-source codebase using low GC Golang.
• Implement new Router capabilities, including Open Federation and various data sources (gRPC, SOAP, etc.).
• Optimize performance, security, and stability of the GraphQL compiler/transpiler.
• Perform internal penetration tests and troubleshoot complex issues with customers.
• Analyze and manage open-source contributions on GitHub.

Requirements

• Senior level of proven Golang development experience in a leading or ownership role.
• Experience working with ASTs and AST transformations.
• Proficiency in writing performant, low GC Go code and knowledge of benchmarking.
• Ability to work within the CET time zone.
• Excellent English communication skills for a fully remote environment.

Nice to have

• Experience with GraphQL, API Gateways, Proxies, or general Networking.
• Experience with OpenAPI, SOAP, gRPC, or Apollo Federation.
• Existing contributions to open-source projects.

Culture & Benefits

• Fully remote and globally distributed work environment with co-working options.
• Discretionary PTO to ensure proper recharge.
• Competitive compensation and healthcare benefits based on local standards.
• Regular team retreats across the globe.
• Freedom to choose preferred work hardware.

Hiring process

• 30-minute intro call with the People team.
• 45-minute technical call followed by a small take-home assignment (1-2h effort).
• Technical review, meetings with founders, and a final culture fit call.