Manual QA Engineer (low-level system testing of broadband equipment)

About the Project:
Harmonic is a leading provider of innovative broadband solutions that deliver video, voice and data to communications providers around the world. GL team participates in development and QA of several generation of these solutions.
The CableOS department is about developing the new software-based network equipment which provides access to Internet/IPTV/VoIP services with using powerful servers.
It is an innovative solution for Internet Service Providers which will allow to get rid of the existing HW equipment and to migrate to the cloud, saving customers the enormous expenses for the support of huge number of hardware network equipment. Currently there are no competitors to this project in the world and Customer offers the opportunity to be at the beginning of the rapid development of the product and the opportunity to take their place in a fast-paced engineering team

We are looking for a strong Middle Manual QA Engineer with 3+ years of commercial experience in manual testing and hands-on experience with Linux and networking.
You will test backend services, REST APIs, and end-to-end scenarios in a technically complex environment. Practical Linux troubleshooting and an understanding of network protocols are essential for this role.

You will:
Perform manual testing of backend services, REST APIs, and end-to-end scenarios.
Analyze requirements, identify gaps and potential risks, and define appropriate test coverage.
Create, maintain, and review test cases, test scenarios, test plans, and test reports.
Execute functional, integration, regression, and exploratory testing.
Test REST APIs using Postman or similar tools and validate data using SQL.
Investigate technical issues in Linux environments using command-line tools, system and application logs, and network diagnostic utilities.
Analyze network connectivity issues and system behavior, applying knowledge of networking concepts and protocols across OSI layers 1–4.
Report, analyze, and track defects, providing clear reproduction steps and relevant technical evidence.
Work closely with developers and Product Owners to clarify requirements and investigate issues.
Identify and communicate quality risks throughout the development process.

You should be able to:
Independently analyze complex requirements and determine appropriate test coverage.
Use Linux command-line tools for troubleshooting, log analysis, and system diagnostics.
Explain networking concepts and protocols across OSI layers 1–4 and describe practical cases of network troubleshooting.
Independently investigate technical issues using Linux, logs, SQL, and network analysis tools.
Clearly document defects, including reproduction steps, expected and actual results, and technical findings.
Take ownership of testing activities and proactively identify potential quality risks.
Collaborate effectively with developers, Product Owners, and QA engineers in a distributed international team.

Must Have
3+ years of commercial experience in manual software testing.
Strong knowledge of software testing theory and test design techniques.
Experience analyzing requirements, identifying gaps and risks, and defining test coverage.
Hands-on experience creating and maintaining test cases, test scenarios, test plans, and defect reports.
Experience with functional, integration, regression, and exploratory testing.
Good practical knowledge of Linux, including command-line usage and log analysis.
Solid understanding of networking concepts and protocols, particularly across OSI layers 1–4.
Practical experience troubleshooting technical or network-related issues.
Good knowledge of SQL.
Hands-on experience with REST API testing using Postman or similar tools.
Understanding of web application architecture and experience using browser Developer Tools.
Basic scripting skills in Python or another scripting language.
Experience with Jira, TestRail, or similar test management and defect-tracking tools.
Upper-Intermediate English (B2+).

Would Be a Plus
Experience testing telecommunications, broadband, networking, or infrastructure products.
Experience with network diagnostic tools such as Wireshark, tcpdump, or similar utilities.
Familiarity with network traffic generators such as iPerf3, TRex, Ixia, or Spirent.
Experience with Kubernetes or containerized environments.
Experience working with network equipment or troubleshooting issues across different network layers.