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Senior Software Development Engineer in Test

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Symphony

B2B

Senior Software Development Engineer in Test

Belfast; Belfast, Northern Ireland, United Kingdom
On-site
Full-time
Posted Sep 15, 2026
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Engineering
On-site

About us @Symphony

Secure. Connected. Intelligent.

Symphony is an AI-powered communication and technology company fueled by interconnected platforms: messaging, voice, directory and analytics.

Our end-to-end encrypted technologies enable over 1,400 institutions to accelerate AI impact, prioritize data security, navigate complex regulatory compliance and optimize business interactions.

 

Role Description:

We are looking for a highly skilled and motivated Senior SDET (Software Development Engineer in Test), C9 Trader to take a lead role in ensuring the quality and reliability of our C9 Trader application supporting both mobile and desktop clients. In this role, you will design, develop, and maintain scalable test automation frameworks, collaborate closely with developers, and drive a shift-left testing mindset within the engineering teams.

As a technical quality leader, you will bring strong expertise in frontend/backend testing, white box testing, and development practices. You will play a key role in supporting the execution of the C9 Trader Test Strategy, coordinating across teams and products, and ensuring the delivery of robust, secure, and performant backend solutions.

If you are passionate about e2e quality, test automation, and engineering excellence, we would love to hear from you!

 

Responsibilities:

  • Take ownership of quality initiatives for C9 Trader components supporting mobile and desktop clients.
  • Design, implement, and maintain test automation frameworks in frontend/backend and white box testing to validate APIs, services, and integrations.
  • Work closely with developers to enable shift-left testing practices and embed quality earlier in the development lifecycle.
  • Ensure reliable test execution across Cloud (GCP/AWS), Kubernetes, and Windows 10/11 environments, including physical Hardware lab PCs.
  • Collaborate across teams and product lines to drive quality alignment and consistency.
  • Mentor other SDETs and contribute to continuous improvement of test strategies, processes, and tools.

 

Required Qualifications:

  • Bachelor’s or Master’s degree in Computer Science, Software Engineering, or related field (or equivalent practical experience).
  • 5+ years of experience in software testing or SDET roles, with a strong focus on backend systems.
  • At least 2+ years in a senior or lead capacity, driving quality initiatives at scale.
  • Strong programming skills in C# and TypeScript (as nice to have).
  • Proven experience with frontend/backend testing and automation frameworks.
  • Hands-on experience in white box testing of APIs, services, WebSocket connections, and backend systems.
  • Familiarity with Windows 10/11 environments.
  • Experience with cloud environments (GCP/AWS), Kubernetes, CI/CD pipelines, Git, and backend testing tools.

 

Compensation:

  • Salary Range: 52,000 - 62,000 base salary per year
  • Bonus Plan

 

Benefits and Perks:

  • Regional specific competitive benefits
  • Build your own Benefits (BYOB) perk
  • Local events, team building, and development opportunities 

 

We are an equal opportunity employer and value diversity at our company. We do not discriminate on the basis of race, religion, color, national origin, gender, sexual orientation, age, marital status, veteran status, or disability status. We will ensure that individuals with disabilities are provided reasonable accommodation to participate in the job application or interview process, to perform essential job functions, and to receive other benefits and privileges of employment.

 

 

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Symphony logo

Symphony

Company profile

Voice AI sims for next-gen employee training

View Symphony

Headquarters

New York, NY, USA

Team size

1-10

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