7 Jan 2026 BBBH62064 Staff Software Engineer - Kotlin, Java, Python £90000 - £100000 per annum [...]

Northern Ireland Water Limited; Belfast; On-site; GBP 80,000 - 100,000; Full time

Job summary

A fast-growing technology company in the energy sector is seeking a Staff Software Engineer in Belfast. The role involves designing and building scalable backend services, mentoring engineers, and collaborating with cross-functional teams. Ideal candidates should have 8+ years of experience in building high-quality solutions and be proficient in languages such as Kotlin, Java, or Scala. Joining this team offers a competitive package, flexible working, and a strong career progression.

Benefits

Competitive package with a 15% bonus

Equity and pension

25 days annual leave plus statutory holidays

Collaborative engineering culture focused on learning and growth

Qualifications

• 8+ years of experience building high-quality, scalable solutions.
• Proficient in languages such as Kotlin, Java, and Scala, or eager to cross-train.
• Experience with SOA/Microservices and CI/CD.

Responsibilities

• Design and build scalable backend services powering the platform.
• Collaborate with Product, Design, and Engineering to deliver new features.
• Mentor and support other engineers.

Skills

Building high-quality, scalable solutions

Proficient in Kotlin, Java, Scala

SOA/Microservices & CI/CD exposure

Cloud experience (GCP/AWS/Azure)

Collaboration with remote teams

Job description

MCS Group is thrilled to be partnering exclusively with fast-growing technology company in the energy sector. They are expanding their Belfast engineering team and are looking for a Staff Software Engineer to join and hit the ground running. The company builds a platform connecting businesses with external partners, helping large-scale operations work more efficiently and reliably.

Day-to-day responsibilities:

• Design and build scalable backend services powering the platform
• Collaborate with Product, Design, and Engineering to deliver new features
• Improve processes and enhance team collaboration
• Mentor and support other engineers

What you need:

• 8+ years experience building high-quality, scalable solutions
• Proficient in languages such as Kotlin, Java, Scala (also open to strong engineers from Java, Go, Python, Scala, or C# backgrounds eager to cross-train)
• SOA/Microservices & CI/CD exposure
• Cloud experience (GCP/AWS/Azure)
• Comfortable collaborating with remote teams
• Quick learner, adaptable with new technologies and tools

What's in it for you:

• High-impact role on a growing platform
• Flexible, modern ways of working with strong career progression
• Competitive package with + 15% bonus, equity, pension, and health cover
• 25 days annual leave + statutory holidays
• Group Critical Illness & Life Cover, Employee Assistance Program
• Flexible working, WFH support, and wellness allowance
• Collaborative engineering culture focused on learning, mentoring, and growth

To speak in absolute confidence about this opportunity please contact Rachael Walker, IT Recruitment Manager at MCS Group 028 969 35487 or click the apply button below.

If this position is not right for you, we have others that are.

Please visit MCS Group www.mcsgroup.jobs to view a wide selection of our current jobs or give us a call 028 9023 5456.

All conversations will be treated in the strictest of confidence.