Senior Ruby on Rails Developer to design and build reporting, payroll deduction calculation logic,

Our valued client is seeking a Senior Ruby on Rails Developer to design and build reporting, payroll deduction calculation logic, and third-party integrations for a payroll processing platform.

Initial 6-month contract opportunity (% remote). Estimated workload of 30 hours per week (flexible, however some daytime hours required).

The successful candidate will work alongside the internal technical and business teams to translate business requirements into accurate reporting and reliable integrations. They will enhance the existing deduction process, implement logic for backdated changes and reconciliation, and support January 1 client implementations while establishing a scalable approach for future clients. Prior payroll/HCM experience is an asset but is not required.

Responsibilities:

• Review existing application logic, data flows, reporting processes, and integrations to identify gaps and recommend improvements
• Develop and enhance functionality using Ruby on Rails and SQL
• Work with internal stakeholders to understand business rules and translate them into accurate calculations and reporting outputs
• Build point-in-time reports reflecting benefit elections and employee/employer cost shares, independent of invoice confirmation status
• Develop change-file logic to identify and transmit updates since the previous file
• Implement logic for retroactive changes, corrections, and reconciliation across differing payroll, benefit, and invoice periods
• Build and adapt integrations to accommodate third-party file specifications, schedules, and business rules
• Diagnose and resolve issues within legacy integrations
• Validate reporting outputs against source data and address discrepancies, edge cases, and integration risks
• Work with the internal data analyst and technical team to deliver functionality supporting January 1 client go-lives
• Develop technical documentation, data flow diagrams, and reusable implementation standards
• Provide hands-on knowledge transfer to enable the internal team to maintain and extend the solution

Must Have Skills:

• Strong hands-on development experience with Ruby on Rails
• Strong SQL skills and experience working with PostgreSQL or equivalent relational databases such as MySQL, SQL Server, or Oracle
• Experience producing accurate reporting outputs and translating business requirements into application logic
• Experience building third-party integrations, with an understanding of the risks and implications of data errors, processing failures, and changes to connected systems
• Hands-on experience using Claude Code for software development
• Experience configuring and troubleshooting SFTP file delivery

Nice-to-Have Skills:

• Experience working with Databricks
• Development experience with JavaScript and/or TypeScript
• Payroll/HCM or benefits administration domain experience, including exposure to platforms such as ADP, Workday, UKG, or Ceridian/Dayforce
• Experience with payroll deduction files, retroactive adjustments, or reconciliation
• Experience orchestrating data workflows using Apache Airflow