SDET- API​/Middleware

Welo Global is hiring an SDET (Software Development Engineer in Test) to bring deep technical rigor to middleware-layer testing. This role requires strong technical expertise across gRPC-Web, Proto3, HTTP/2, JSON-RPC/REST, proxy-based traffic inspection, and API scripting. The primary responsibility is to observe and reconstruct the network interactions generated by the onboarding UI, including request/response structures, schemas, headers, identifiers, Enums, and client-injected parameters.

This is primarily an API/network analysis and evidence-generation role rather than a conventional UI automation or regression-testing role. The resource will produce sanitized network evidence and controlled, benign tracer replay scripts for downstream backend validation.

Title: SDET - API/Middleware

Rate: $9.50/hr

Start Date: 19th October

Duration: 5 Weeks

Commitment: 35 Hours per Week

Location: India (Remote)

Job Type: Freelance

• Design, build, and maintain automated API test suites covering gRPC-Web, Proto3, HTTP/2, and JSON-RPC/REST based services
• Export clean, sanitized HAR/network evidence whilemaintainingtraceability between UI actions and corresponding network requests.
• Map relevant schemas, headers, identifiers, routing information, and client-injected parameters.
• Use proxy tools such as Mitmproxy, Charles Proxy, and browser
  
  DevToolsto inspect, intercept, andvalidatenetwork traffic between client and server
• Develop andmaintainAPI automation scripts using Python, Postman, andcURLfor functional and regression testing
• Analyzeprotocol-level request/responsebehaviortoidentifydefects related to serialization, encoding, and transport
• Inspect andvalidaterequest payload structure, including system-level headers (e.g., auth tokens, routing identifiers) and internal/hidden parameters, ensuring correct handling under both valid and malformed conditions
• Collaborate with backend and middleware engineers to define testable contracts and edge-case scenarios
• Continuously improve test automation frameworks for reliability, speed, and maintainability
• Document technical findings, automation coverage, and known protocol-level limitations

• Strong hands-onexpertiseof3-5+ years
  withgRPC-Web, Proto3, HTTP/2, and JSON-RPC/REST protocols
• Proficiency with proxy/traffic inspection tools including
  
  Mitmproxy, Charles Proxy, and browser
  
  Dev Tools
• Solid scripting/programming skills in Python, with practical use of Postman andcURLfor API automation
• Experience designing andmaintainingautomated test suites for middleware or API-layer services
• Working understanding of API request structure, including headers, auth tokens, and internal/system parameters, and how to test for their correct handling
• Understanding of software engineering practices as applied to test automation (version control, CI integration, code review)
• Strong debugging skills at the network/protocol level
• Experience analysing browser-generated network traffic and reconstructing API behaviour is strongly preferred.
• Experience with HAR analysis, API schema reconstruction, or controlled API replay is strongly preferred.
• Ability to work within approved staging/test environments and follow defined data-handling and test-authorization requirements is required.