Senior Software Engineer: Legacy Modernization & Full-Stack

Daxko, LLC; Centennial (CO); Hybrid; USD 140,000 - 210,000; Full time

Benefits offered by this job

Flexible PTO

Health insurance

Fitness reimbursement

401(k) matching

Parental leave

Casual work environment

Remote & Hybrid

Job summary

Daxko, LLC is seeking a senior software engineer to bridge legacy systems and new product experiences for fitness and wellness organizations. You will own full-stack responsibilities across backend, frontend, and deployment workflows, influencing architecture and engineering patterns.

Hybrid role with 1 day in-office weekly. You will work across Java/Spring Boot, React/TypeScript, SQL Server, Docker, AWS, and CI/CD pipelines, delivering testable services and modern interfaces while mentoring

Qualifications

• 7+ years of professional software engineering with full-stack ownership.
• Strong Java and Spring Boot experience, REST API design and service-layer architecture.
• Proficient in React and TypeScript for modern SPAs.
• Deep SQL Server expertise: query optimization and indexing.
• Experience in complex legacy systems and incremental improvements.
• Proven testing discipline across unit, integration, and UI automation.
• Clear communication in code reviews and cross-functional talks.

Responsibilities

• Build and maintain REST APIs in Java/Spring Boot across generations.
• Own data access layer, tuning queries and migrations (Flyway).
• Develop UI in React/TypeScript within a pnpm monorepo.
• Replace ColdFusion paths with modern services safely.
• Package and deploy with Docker; CI/CD via GitLab.
• Collaborate on testing with JUnit, WireMock, Vitest, Playwright/Selenium.
• Mentor teammates and define engineering patterns.

Skills

Java & Spring Boot

React & TypeScript

SQL Server

REST API design

Code reviews

Mentoring

Testing discipline

Tools

Docker

Kubernetes

GitLab CI

OpenAPI

Flyway

Job description

Daxko, LLC is seeking a senior software engineer to bridge legacy systems and new product experiences for fitness and wellness organizations. You will own full-stack responsibilities across backend, frontend, and deployment workflows, influencing architecture and engineering patterns.

Hybrid role with 1 day in-office weekly. You will work across Java/Spring Boot, React/TypeScript, SQL Server, Docker, AWS, and CI/CD pipelines, delivering testable services and modern interfaces while mentoring