Senior Mainframe Developer Jobs in Ohio

INTRODUCTION

Be Here. Be Great. Working for a leader in the insurance industry means opportunity for you. Great American Insurance Group's member companies are subsidiaries of American Financial Group. We combine a "small company" culture where your ideas will be heard with "big company" expertise to help you succeed. With over 30 specialty and property and casualty operations, there are always opportunities here to learn and grow.

At Great American, we value and recognize the benefits derived when people with different backgrounds and experiences work together to achieve business results. Our goal is to create a workplace where all employees feel included, empowered, and enabled to perform at their best.

P&C IT Services provides professional services to help our business units and corporate functions use technology to create, manage, and optimize information and business processes. IT Services can include a wide range of activities such as: software development, data management, Cloud services, IT security, network security, technical support, establishing and overseeing access rights, procuring and maintaining equipment or software, managing the infrastructure, and defining security procedures. The overall goal of IT Services is to provide technology solutions that increase efficiency, reduce costs, and give our company a competitive advantage over our competitors.

Great American’s culture is built on connection, shared learning, and strong relationships. To support this, employees in this role are expected to be on-site a minimum of two days a week, with the potential to work three days remotely. Core in-office days are Tuesday and Thursday but will be determined by business needs.

The Great American Software Lab is looking for a collaborative, full-stack developer who is a passionate AI champion and change agent - an engineer with strong backend experience in Java/Spring Boot, .NET, or both, who loves close collaboration, embraces XP practices, and adapts comfortably to frequent context switching. This individual will lead from wherever they sit, bringing others along as they introduce new ways of working and help teams rethink how software gets built in an AI-augmented world. They stay ahead of the curve, embrace new tools as the industry evolves, and are genuinely curious about where software development is headed. They see AI as a fundamental shift in how great software gets built, and they're excited to help shape what that looks like in practice. If you thrive in a fast-moving, team-first environment and get energized by solving hard problems together, we'd love to hear from you.

RESPONSIBILITIES & COMPETENCIES:

• Partner with fellow practice leads to set the north star for architectural patterns, design principles, and implementation standards, bridging practitioners and architects to ensure alignment with organizational goals.
• Continuously assess development practices and drive improvements, pairing with teams to teach modern techniques and XP practices.
• Champion and scale AI-first delivery across the organization — evaluating emerging tools, establishing practices and guardrails, and owning our internal playbook for AI-assisted development.
• Bring deep technical expertise across the full stack (Java/Spring Boot, .NET, or both), connecting business domain context to architectural design within our AI toolset.
• Act as a change agent, cultivating a culture of continuous improvement, experimentation, and curiosity about where software development is headed.

DESIRED SKILLS/EXPERIENCE:

• Ability to dive into large, polyglot codebases and contribute quickly while you learn.
• Comfortable working across multiple programming languages and paradigms.
• Genuinely curious about new languages, patterns, and ways of thinking about problems.
• Experience leveraging AI coding tools tactically and strategically throughout your engineering workflow, with a particular emphasis on agentic approaches.
• Demonstrable ability to research and break down complex problems into discrete, actionable parts.
• Empathy for your colleagues and a habit of giving and receiving feedback openly and continuously.
• Enthusiastic about (or at least open to) Test-Driven Development (TDD).
• Experience in a pair programming environment (preferred).
• Experience supporting and troubleshooting complex systems, with the ability to dig into logs, metrics, and streaming data to diagnose issues quickly.
• Has mentored others in a professional setting.
• Experience in the Insurance industry (major plus).
• BA/BS in Computer Science or equivalent experience.
• Minimum 8 years of professional programming experience.

LANGUAGES AND FRAMEWORKS:

• Java/Spring Boot
• .NET 8+
• VueJS
• Testing Frameworks (unit and acceptance)
• Python (a plus)

CORE TOOLS:

• Git
• Github Copilot (CLI preferred)
• IDEs like IntelliJ, VS Code, Visual Studio with Resharper or Rider
• Relational Databases / NoSQL Databases
• Redis
• RabbitMQ

PLATFORMS:

• Cloud Native Platforms (like Pivotal Cloud Foundry/Tanzu Application Service, Azure/Kubernetes)
• GitHub
• GitHub Actions including CI/CD pipelines

BUSINESS UNIT:

Property & Casualty IT Services

BENEFITS:

We offer competitive benefits packages for full-time and part-time employees*. Full-time employees have access to medical, dental, and vision coverage, wellness plans, parental leave, adoption assistance, and tuition reimbursement. Full-time and eligible part-time employees also enjoy Paid Time Off and paid holidays, a 401(k) plan with company match, an employee stock purchase plan, and commuter benefits.

Compensation varies by role, level, and location and is influenced by skills, experience, and business needs. Your recruiter will provide details about benefits and specific compensation ranges during the hiring process.

*Excludes seasonal employees and interns.