66 Mainframe Developer jobs in the United Kingdom

Job Title:  Mainframe Developer

Job Description:

• We are seeking a seasoned Mainframe Developer with strong expertise in IBM DB2 and core mainframe technologies.
li>The role involves designing, developing, testing, and maintaining high-performance mainframe applications using COBOL, IMS, and z/OS.
• The ideal candidate will also manage and optimize data with IBM DB2 and promptly troubleshoot production issues to ensure system reliability.

About Us:  

Ascendion is a global, leading provider of AI-first software engineering services, delivering transformative solutions across North America, APAC, and Europe. We are headquartered in New Jersey. We combine technology and talent to deliver tech debt relief, improve engineering productivity solutions, and accelerate time to value, driving our clients’ digital journeys with efficiency and velocity. Guided by our “Engineering to the power of AI” (EngineeringAI) methodology, we integrate AI into software engineering, enterprise operations, and talent orchestration, to address critical challenges of trust, speed, and capital.

Your new company

You will be joining a fantastic Public Sector organisation who are utilising Power Platform and PowerAutomate to automate within the organisation to make improvements, enabling time and funds to be saved and utilised in other areas.

Purpose of your role
As an Application Developer, you will be responsible for

• Developing interfaces to existing systems that enhance the end user's experience
• Build new applications that deliver efficiency and modernisation to the organisation.
• You will need to interpret systems already in use within the organisation to gather an understanding of their functionality.

Day-to-day typical duties

• Using Microsoft Power Platform and PowerAutomate, building Canvas and Model driven Apps to design and develop applications that deliver modernisation and efficiency to the organisation
• To be forward-thinking and proactive in suggesting future enhancements that could benefit the organisation

What you'll need to succeed

• Minimum of two years' hands-on experience with Power Platform development - including PowerAutomate, and building Canvas Apps and Model Driven Apps
• Living within commuting distance of Hampshire
• Advantageous to have experience with Portal and Power Pages, but not essential

What you'll get in return

• Hybrid working - one day together in the office once a fortnight
• Great pension and benefits package including Local Government Pension, 29 days annual leave, plus bank holidays
• Support in gaining certifications/ qualifications in Power Platform
• Free onsite parking

What you need to do now

If you're interested in this role, click 'apply now' to forward an up-to-date copy of your CV, or call us now.

If this job isn't quite right for you, but you are looking for a new position, please contact us for a confidential discussion about your career.

Hays Specialist Recruitment Limited acts as an employment agency for permanent recruitment and employment business for the supply of temporary workers. By applying for this job you accept the T&C's, Privacy Policy and Disclaimers which can be found at (url removed)

ECS Resource Group are currently working in partnership with a global managed service provider who's end client is in the Manufacturing sector. We are assisting them with the search for a Applications Developer on a contract basis. This is a contract that is inside IR35 and is based on-site every day in Dumfries & Galloway, Scotland.

Key Responsibilities:

• Modify and enhance the legacy MES system to integrate with SAP and SAP Middleware.

• Develop and maintain integration components using .NET (C#, VB, ASP) and REST/WEB APIs.

• Analyse and optimise SQL queries to ensure efficient data exchange between MES and SAP.

• Collaborate with cross-functional IT teams to align integration efforts and resolve technical issues.

• Support and troubleshoot interactions between AS/400-based MES and modern SAP infrastructure

Key Skills:

• Strong experience in Microsoft .NET development (C#, VB, ASP.NET).

• Proficient in Microsoft SQL for data manipulation and integration.

• Solid understanding of RESTful APIs and Web Services for system connectivity.

• Experience working with AS/400 systems, particularly in manufacturing or MES environments.

• Ability to bridge legacy and modern systems with clear documentation and clean code practices.

Further job details available upon application.

Please note, due to internal capabilities it will be difficult for us to take internal calls regarding your application - please direct all queries to (url removed) , and they will be responded to, alongside your application ASAP. If you haven't received a response within 1 working day, please call the direct line which is (phone number removed).

ECS Recruitment Group Ltd is acting as an Employment Business in relation to this vacancy.

We are seeking Mid-Level Application Software Engineers to join our clients growing team where you’ll play a key role in designing and developing cutting-edge software for audio and live performance technology, collaborating with a supportive and dynamic team dedicated to enhancing the live experience for artists and audiences alike.

What You’ll Do

• Develop and maintain desktop applications for audio and live performance environments
li>Work on cross-platform solutions for Embedded Linux, macOS, and iOS
• Collaborate in Agile teams, contributing to sprint planning, code reviews, and CI/CD pipelines
• Build intuitive graphical user interfaces (GUI) with Qt/QtQuick
• Integrate networking features using TCP/IP for seamless device communication
• Support the evolution of products that shape the sound of live performances globally

What We're Looking For

• Strong proficiency in C++ and C#
• Experience with multithreading and complex, concurrent software systems
• Familiarity with cross-platform desktop development (Embedded Linux/macOS/iOS)
• Understanding of Agile methodologies, CI/CD, and version control
• Networking knowledge (TCP/IP)
• Bonus: Experience or interest in Delphi, Flutter, and full-stack development
• Appreciation for audio mixing technology and live streaming
• Interest in hardware/software integration (FPGA/embedded systems)

You’ll Thrive Here If You…

• Are self-motivated, proactive, and eager to solve complex problems
• Communicate effectively and enjoy collaborating in a team
• Bring prior experience in audio technology or related fields (a plus, not a must)

Why Join?

• Innovative Culture: Help develop new products and enhance existing solutions at the forefront of audio technology
• Real-World Impact: Your work will be used by leading audio professionals on stages and in studios around the world
• Career Growth: Structured progression and opportunities to make a tangible impact
• Work-Life Balance: Flexible hours and a hybrid office model
• Collaborative Team: Work alongside passionate engineers dedicated to delivering the best in live audio technology

If you’re excited about shaping the future of live performance technology and want to work with a team that shares your passion for audio and music, apply now!

We are seeking Mid-Level Application Software Engineers to join our clients growing team where you’ll play a key role in designing and developing cutting-edge software for audio and live performance technology, collaborating with a supportive and dynamic team dedicated to enhancing the live experience for artists and audiences alike.

What You’ll Do

• Develop and maintain desktop applications for audio and live performance environments
li>Work on cross-platform solutions for Embedded Linux, macOS, and iOS
• Collaborate in Agile teams, contributing to sprint planning, code reviews, and CI/CD pipelines
• Build intuitive graphical user interfaces (GUI) with Qt/QtQuick
• Integrate networking features using TCP/IP for seamless device communication
• Support the evolution of products that shape the sound of live performances globally

What We're Looking For

• Strong proficiency in C++ and C#
• Experience with multithreading and complex, concurrent software systems
• Familiarity with cross-platform desktop development (Embedded Linux/macOS/iOS)
• Understanding of Agile methodologies, CI/CD, and version control
• Networking knowledge (TCP/IP)
• Bonus: Experience or interest in Delphi, Flutter, and full-stack development
• Appreciation for audio mixing technology and live streaming
• Interest in hardware/software integration (FPGA/embedded systems)

You’ll Thrive Here If You…

• Are self-motivated, proactive, and eager to solve complex problems
• Communicate effectively and enjoy collaborating in a team
• Bring prior experience in audio technology or related fields (a plus, not a must)

Why Join?

• Innovative Culture: Help develop new products and enhance existing solutions at the forefront of audio technology
• Real-World Impact: Your work will be used by leading audio professionals on stages and in studios around the world
• Career Growth: Structured progression and opportunities to make a tangible impact
• Work-Life Balance: Flexible hours and a hybrid office model
• Collaborative Team: Work alongside passionate engineers dedicated to delivering the best in live audio technology

If you’re excited about shaping the future of live performance technology and want to work with a team that shares your passion for audio and music, apply now!

ECS Resource Group are currently working in partnership with a global managed service provider who's end client is in the Manufacturing sector. We are assisting them with the search for a Applications Developer on a contract basis. This is a contract that is inside IR35 and is based on-site every day in Dumfries & Galloway, Scotland.

Key Responsibilities:

• Modify and enhance the legacy MES system to integrate with SAP and SAP Middleware.

• Develop and maintain integration components using .NET (C#, VB, ASP) and REST/WEB APIs.

• Analyse and optimise SQL queries to ensure efficient data exchange between MES and SAP.

• Collaborate with cross-functional IT teams to align integration efforts and resolve technical issues.

• Support and troubleshoot interactions between AS/400-based MES and modern SAP infrastructure

Key Skills:

• Strong experience in Microsoft .NET development (C#, VB, ASP.NET).

• Proficient in Microsoft SQL for data manipulation and integration.

• Solid understanding of RESTful APIs and Web Services for system connectivity.

• Experience working with AS/400 systems, particularly in manufacturing or MES environments.

• Ability to bridge legacy and modern systems with clear documentation and clean code practices.

Further job details available upon application.

Please note, due to internal capabilities it will be difficult for us to take internal calls regarding your application - please direct all queries to (url removed) , and they will be responded to, alongside your application ASAP. If you haven't received a response within 1 working day, please call the direct line which is (phone number removed).

ECS Recruitment Group Ltd is acting as an Employment Business in relation to this vacancy.

Your new company

You will be joining a fantastic Public Sector organisation who are utilising Power Platform and PowerAutomate to automate within the organisation to make improvements, enabling time and funds to be saved and utilised in other areas.

Purpose of your role
As an Application Developer, you will be responsible for

• Developing interfaces to existing systems that enhance the end user's experience
• Build new applications that deliver efficiency and modernisation to the organisation.
• You will need to interpret systems already in use within the organisation to gather an understanding of their functionality.

Day-to-day typical duties

• Using Microsoft Power Platform and PowerAutomate, building Canvas and Model driven Apps to design and develop applications that deliver modernisation and efficiency to the organisation
• To be forward-thinking and proactive in suggesting future enhancements that could benefit the organisation

What you'll need to succeed

• Minimum of two years' hands-on experience with Power Platform development - including PowerAutomate, and building Canvas Apps and Model Driven Apps
• Living within commuting distance of Hampshire
• Advantageous to have experience with Portal and Power Pages, but not essential

What you'll get in return

• Hybrid working - one day together in the office once a fortnight
• Great pension and benefits package including Local Government Pension, 29 days annual leave, plus bank holidays
• Support in gaining certifications/ qualifications in Power Platform
• Free onsite parking

What you need to do now

If you're interested in this role, click 'apply now' to forward an up-to-date copy of your CV, or call us now.

If this job isn't quite right for you, but you are looking for a new position, please contact us for a confidential discussion about your career.

Hays Specialist Recruitment Limited acts as an employment agency for permanent recruitment and employment business for the supply of temporary workers. By applying for this job you accept the T&C's, Privacy Policy and Disclaimers which can be found at (url removed)

**Introduction**
At IBM CIC, we deliver deep technical and industry expertise to a wide range of public and private sector clients in the UK.
A career in IBM CIC means you'll have the opportunity to work with visionaries across multiple industries to improve the hybrid cloud and AI journey for the most innovative and valuable companies in the world. Your ability to accelerate impact and make meaningful change for your clients is enabled by our strategic partner ecosystem and our robust technology platforms across the IBM portfolio.
Curiosity and a constant quest for knowledge serve as the foundation to success here. You'll be encouraged to challenge the norm, investigate ideas outside of your role, and come up with creative solutions which impact a wide network of clients, whom may be at their site or one of our CIC or IBM locations. Our culture of evolution centres on long-term career growth and development opportunities in an environment that embraces your unique skills and experience.
We offer:
* Many training opportunities from classroom to e-learning, mentoring and coaching programs and the chance to gain industry recognized certifications
* Regular and frequent promotion opportunities to ensure you can drive and develop your career with us
* Feedback and checkpoints throughout the year
* Diversity & Inclusion as an essential and authentic component of our culture through our policies and process as well as our Employee Champion teams and support networks
* A culture where your ideas for growth and innovation are always welcome
* Internal recognition programs for peer-to-peer appreciation as well as from manager to employees
* Tools and policies to support your work-life balance from flexible working approaches, sabbatical programs, paid paternity leave, maternity leave and an innovative maternity returners scheme
* More traditional benefits, such as 25 days holiday (in addition to public holidays), online shopping discounts, an Employee Assistance Program, a group personal pension plan of an additional 5% of your base salary paid by us monthly to save for your future.
**Your role and responsibilities**
We are looking for an AWS Cloud Full Stack Application Developer to contribute to the design, development, and maintenance of cloud-based applications. This role requires a solid foundation in both frontend and backend development, with hands-on experience using AWS services. The ideal candidate will have a passion for building scalable, efficient, and secure applications while working in a collaborative Agile environment.
Responsibilities
* Build and maintain full-stack applications deployed on AWS, ensuring high performance and reliability.
* Design and implement APIs and microservices using Node.js, Python, or Java.
* Develop responsive user interfaces with React.js, Angular, or Vue.js, following best practices for performance and accessibility.
* Utilise AWS services such as Lambda, API Gateway, S3, DynamoDB, and RDS to enhance application functionality.
* Implement security best practices, optimise application performance, and ensure scalability.
* Support the development of CI/CD pipelines and automate deployments using AWS CodePipeline or similar tools.
* Work closely with product managers, designers, and other developers in an Agile development environment.
* Write clean, maintainable code and contribute to peer code reviews and technical documentation.
**Required technical and professional expertise**
* 3+ years of experience in full-stack development, including cloud-based applications.
* Proficiency in JavaScript/TypeScript and modern frontend frameworks such as React.js, Angular, or Vue.js.
* Hands-on experience with backend development using Node.js, Python, or Java.
* Familiarity with AWS services such as Lambda, API Gateway, DynamoDB, RDS, and IAM.
* Experience working with relational (PostgreSQL, MySQL) and NoSQL (DynamoDB, MongoDB) databases.
* Understanding of unit testing, integration testing, and debugging techniques.
* Knowledge of Git, version control, and deployment automation practices
As an equal opportunities' employer, we welcome applications from individuals of all backgrounds. However, for you to be eligible for this role, you must have the valid right to work in the UK. Unfortunately, we do not offer visa sponsorship and have no future plans to do so. You must be a resident in the UK and have been living continuously in the UK for the last 10 years. You must be able to hold or gain a UK government security clearance.
**Preferred technical and professional experience**
* AWS certification (e.g., AWS Certified Developer - Associate).
* Experience with Infrastructure as Code (Terraform, CloudFormation, or AWS CDK).
* Knowledge of authentication methods such as OAuth, JWT, or AWS Cognito.
* Exposure to containerised applications using Docker, ECS, or Kubernetes.
IBM is committed to creating a diverse environment and is proud to be an equal-opportunity employer. All qualified applicants will receive consideration for employment without regard to race, color, religion, sex, gender, gender identity or expression, sexual orientation, national origin, caste, genetics, pregnancy, disability, neurodivergence, age, veteran status, or other characteristics. IBM is also committed to compliance with all fair employment practices regarding citizenship and immigration status.