Senior Software Engineer - Legacy Modernization & Modern APIs

re-zoo-me; Centennial, Northern (CO, KY); Hybrid; USD 111,000 - 160,000; Full time

Benefits offered by this job

Flexible PTO

Health insurance

Dental insurance

Vision insurance

Fitness reimbursement

401(k) matching

Parental leave

Job summary

Daxko is hiring a senior software engineer to modernize a multi-generation codebase while delivering new product experiences for fitness and wellness organizations.

You will own REST APIs in Java/Spring Boot, build frontend with React/TypeScript, and work across backend, frontend, and deployment pipelines in a pnpm monorepo. This role requires 7+ years of full-stack experience and strong SQL Server skills.

Qualifications

• 7+ years of professional software engineering with full-stack ownership.
• Strong production experience with Java and Spring Boot and REST API design.
• Expertise in React and TypeScript for modern SPAs.
• Deep SQL Server experience including query optimization and indexing.
• Experience in complex legacy systems and incremental improvements.
• Disciplined testing across unit, integration, and UI layers.
• Excellent communication in cross-functional reviews.

Responsibilities

• Build and maintain REST APIs in Java/Spring Boot across generations.
• Own data access layer, including query tuning and migrations.
• Develop frontend experiences using React/TypeScript in a monorepo.
• Refactor ColdFusion paths to modern services with safety.
• Package and deploy with Docker; pipeline in GitLab CI.
• Contribute to testing, reviews, and engineering patterns.

Skills

Full-stack ownership

Java & Spring Boot

React & TypeScript

SQL Server

Legacy system modernization

Testing discipline

Clear communication

Tools

Docker

Kubernetes

GitLab CI

AWS

Job description

Daxko is hiring a senior software engineer to modernize a multi-generation codebase while delivering new product experiences for fitness and wellness organizations.

You will own REST APIs in Java/Spring Boot, build frontend with React/TypeScript, and work across backend, frontend, and deployment pipelines in a pnpm monorepo. This role requires 7+ years of full-stack experience and strong SQL Server skills.