Software Developer

Marvel Consulting Group Oy; Espoo; On-site; EUR 70,000 - 95,000; Full time

Job summary

Marvel Consulting Group Oy in Finland seeks an experienced Senior/Lead software developer who thrives on legacy systems. You will work independently in client projects, maintain and modernize business-critical applications, and ensure reliable operation of core back-end processes.

You will analyze existing solutions, implement safe changes, and share best practices. The role may be permanent or project-based, offering opportunities to influence complex systems and collaborate across stakeholders.

Qualifications

• 5+ years of experience in software development for legacy systems.
• Experience maintaining and developing business-critical systems.
• Strong expertise in one or more legacy technologies.
• Understanding of databases, integrations, and batch processes.
• Experience in system modernization and migrations is advantageous.
• Ability to work independently on client projects and communicate solutions clearly.

Responsibilities

• Designing, developing, and maintaining business-critical legacy systems.
• Developing and enhancing COBOL, mainframe, or other legacy applications.
• Planning and implementing system modernization and migrations.
• Designing integrations between legacy and modern systems.
• Improving performance, security, and reliability of applications.
• Analyzing and resolving production issues.
• Collaborating with clients and development teams on solutions.

Skills

Legacy systems

Independent client work

Databases

Integrations

System modernization

Batch processing

Tools

COBOL

z/OS

IBM Mainframe

JCL

CICS

DB2

IMS

FORTRAN

LISP

REXX

VSAM

Job description

You are an experienced software developer, a Senior or Lead level professional, for whom legacy systems are familiar territory. You operate independently in client projects and trust your own expertise. You understand that business-critical systems still form the backbone of many organizations' operations, and you know how to develop, maintain, and modernize them in a controlled manner.

You enjoy working with complex systems and understand their business significance. You can analyze existing solutions, make changes safely, and ensure the reliable operation of systems in the future. You are also able to share your expertise and best practices in an understandable and practical way.

You may be looking for your next permanent position or your next project as an entrepreneur.

Skills we are looking for:

• At least 5 years of experience in software development for legacy systems
• Experience in maintaining and developing business-critical systems
• Strong expertise in one or more legacy technologies
• Understanding of databases, integrations, and batch processes
• Experience in system modernization and migration projects is considered an advantage
• Ability to work independently in client projects and communicate technical solutions clearly

We value experience in technologies such as: COBOL, z/OS, IBM Mainframe, JCL, CICS, DB2, IMS, FORTRAN, LISP, REXX, VSAM

We do not expect you to know all the listed technologies — if you have strong experience in legacy environments and their development, we would love to hear from you!

Your potential tasks:

• Designing, developing, and maintaining business-critical legacy systems
• Developing and further developing COBOL, mainframe, or other legacy applications
• Planning and implementing system modernizations and migrations
• Designing and implementing integrations between legacy and modern systems
• Improving application performance, security, and reliability
• Analyzing and resolving problem situations in production environments
• Collaborating with clients, development teams, and other stakeholders in developing business-critical solutions

At least 5 years of experience in software development for legacy systems, Experience in maintaining and developing business-critical systems, Strong expertise in one or more legacy technologies, Understanding of databases, integrations, and batch processes, Ability to work independently in client projects and communicate technical solutions clearly