SDET- API/Middleware

Job Overview

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.

Project Details

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

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 while maintaining traceability 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 DevTools to inspect, intercept, and validate network traffic between client and server

Develop and maintain API automation scripts using Python, Postman, and cURL for functional and regression testing

Analyze protocol-level request/response behavior to identify defects related to serialization, encoding, and transport

Inspect and validate request 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

Required Qualifications

Strong hands-on expertise of 3-5+ years with gRPC-Web, Proto3, HTTP/2, and JSON-RPC/REST protocols

Proficiency with proxy/traffic inspection tools including Mitmproxy, Charles Proxy, and browser DevTools

Solid scripting/programming skills in Python, with practical use of Postman and cURL for API automation

Experience designing and maintaining automated 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.

Originally posted on Himalayas