Senior Java Developer (AI)

Location: Sofia, Bulgaria; fully distributed and remote

Company

hirify.global provides global payment processing and acquiring services for online, mobile, in-store, and telephone payments, including fraud management and payment optimization.

What you will do

• Design and implement complex workflows, APIs, and UI backends for payment platforms.
• Build, scale, and maintain highly available payment services targeting 99.99%+ uptime.
• Apply TDD with JUnit and other testing tools.
• Use AI coding assistants and agents for implementation, refactoring, test generation, code review, and legacy code exploration while owning the quality of the output.
• Contribute to shared AI tooling, including agent skills, project instructions, prompt templates, and MCP server configurations.
• Apply secure and responsible AI practices in a PCI DSS environment, protecting cardholder data, secrets, and other sensitive information.

Requirements

• 9–10+ years of experience with core Java and/or J2EE and Spring.
• Knowledge of ORM solutions such as Hibernate and open-source databases including MySQL and/or PostgreSQL.
• Experience with JavaScript and solid front-end skills.
• Hands-on experience with TDD/BDD, JUnit, and AI coding assistants or agentic tools, including prompt and specification writing and critical review of AI-generated code.
• Practical understanding of MCP servers and integrations with tools such as GitHub, Jira, Confluence, and databases, including prompt-injection and over-permissioning risks.
• CV must be submitted in English.

Nice to have

• Experience building APIs with current standards and SPA front-end applications.
• Experience with large codebases, legacy modernization, and AI-assisted refactoring.
• Experience creating agent skills, custom instructions, reusable AI workflows, MCP servers, or Java tool integrations.
• Experience integrating LLMs into Java services using technologies such as Spring AI, LangChain4j, Amazon Bedrock, or Claude API.
• Security, Linux, DevOps, AWS, Ansible, Terraform, or payment-industry experience.

Culture & Benefits

• Fully distributed and remote working environment.
• Casual atmosphere, modern hardware, and a challenging, growing business.
• Professional development support through books, training, and certifications.
• Team-building activities and social events.
• 25 paid holiday days, plus one additional day for every two years with the company.