Remote SDET: API & Middleware Test Automation

Welocalize India Llp; United States; Remote; USD 12,000 - 17,000; Full time

Job summary

Welo Global is seeking a highly skilled SDET to perform API and middleware testing, focusing on network analysis, HAR evidence, and replay scripting. The role emphasizes API scripting, protocol-level inspection, and sanitized evidence generation rather than UI automation.

Remote from India with a freelance engagement of 5 weeks at $9.50 per hour, ~35 hours per week. You will collaborate with backend engineers, design test contracts, and maintain test automation for complex middleware services

Qualifications

• 3–5+ years hands-on experience with gRPC-Web, Proto3, HTTP/2, and JSON-RPC/REST
• Proficiency with proxy/traffic inspection tools including Mitmproxy, Charles Proxy, and browser DevTools
• Strong Python scripting and API automation using Postman and cURL

Responsibilities

• 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 asMitmproxy, Charles Proxy, and browserDevToolssto 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

Skills

API testing

Network protocol analysis

SDET fundamentals

Python scripting

Tools

Mitmproxy

Charles Proxy

browser DevTools

Postman

cURL

Job description

Welo Global is seeking a highly skilled SDET to perform API and middleware testing, focusing on network analysis, HAR evidence, and replay scripting. The role emphasizes API scripting, protocol-level inspection, and sanitized evidence generation rather than UI automation.

Remote from India with a freelance engagement of 5 weeks at $9.50 per hour, ~35 hours per week. You will collaborate with backend engineers, design test contracts, and maintain test automation for complex middleware services