Senior Software Engineer- Full Stack

Daxko, LLC; Centennial (CO); On-site; 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

This role sits at the intersection of legacy modernization and modern product development. You'll work across a multi-generation codebase, helping move business logic off older systems and into cleaner, testable services, while also building new product experiences used by fitness and wellness organizations every day. You'll need to go wide and deep: database performance, backend APIs, frontend UX, deployment pipelines, and AI-assisted development workflows are all in scope. If you do your best work when you can see the whole system and make pragmatic decisions in a complex environment, this role is built for you.

What you’ll do

• Build and maintain REST APIs in Java and Spring Boot, consolidating legacy code into modern domain packages across multiple API generations
• Own the full data access layer: query tuning, JPA specifications, Flyway migrations, and performance-sensitive reporting paths in SQL Server
• Build product experiences in a pnpm monorepo using React, TypeScript, Vite, and MUI, with TanStack Query and Zod handling data fetching and validation
• Read, debug, and incrementally replace behavior in the ColdFusion codebase, retiring legacy paths safely as modern services come online
• Package and deploy services with Docker and GitLab CI, working across AWS (S3, DynamoDB, KMS) and Kubernetes
• Contribute to integration and unit testing using JUnit, WireMock, Vitest, and Playwright/Selenium
• Mentor teammates, deliver actionable code reviews, and help define engineering patterns across backend, frontend, and platform concerns

What you’ll bring

• 7+ years of professional software engineering experience with meaningful full-stack ownership
• Solid production experience with Java and Spring Boot, including REST API design and service-layer architecture
• Strong React and TypeScript skills in real, modern single-page applications
• Deep SQL Server experience, including query optimization, indexing strategy, and diagnosing slow paths in production
• A track record of working in complex legacy systems: tracing cross-service behavior, shipping incremental improvements, and not breaking things
• A testing discipline that spans unit, integration, and UI automation layers
• Clear communication, both in code review and cross-functional conversations where you can explain tradeoffs without leaning on jargon

Nice to have

• Experience migrating off legacy platforms like ColdFusion or similar
• Familiarity with OpenAPI-first development and contract-driven frontend/backend integration
• Background in containerized delivery (Docker, Kubernetes) and CI/CD tooling
• Experience with multi-tenant SaaS patterns, distributed tracing, or message-driven architectures like RabbitMQ or Kafka

Work Arrangement

Hybrid schedule with 1 day per week in-office for collaboration, planning, and team connection. Remote-friendly the remainder of the week, with the expectation of overlap with team working hours and participation in code review, incident response, and planning.

Additional Information

Daxko is dedicated to pursuing and hiring a diverse workforce. We are committed to diversity in the broadest sense, including thought and perspective, age, ability, nationality, ethnicity, orientation, and gender. The skills, perspectives, ideas, and experiences of all of our team members contribute to the vitality and success of our purpose and values. We truly care for our team members, and this is reflected through our offices, and benefits, and great perks. These perks are only for our full-time team members.

Some of our favorites include:

• Flexible paid time off
• Affordable health, dental, and vision insurance options
• Monthly fitness reimbursement
• 401(k) matching
• New-Parent Paid Leave
• Casual work environments
• Flexible work options - remote & hybrid

All your information will be kept confidential according to EEO guidelines.