Senior Full-Stack Engineer — Modernize & Build APIs

Daxko; Centennial (CO); Hybrid; USD 110,800 - 159,600; Full time

Benefits offered by this job

Flexible paid time off

Health, dental, and vision insurance

Monthly fitness reimbursement

401(k) matching

New-Parent Paid Leave

Casual work environment

Remote & hybrid options

Job summary

Daxko builds software for fitness, wellness, and community organizations, enabling member management, payments, and engagement.

This role combines legacy modernization with modern product development across a multi-generation codebase, including backend APIs, frontend UX, and deployment pipelines.

You'll work in a hybrid setup with in-person collaboration one day a week and remote work otherwise, contributing to tests, reviews, and engineering patterns across the stack.

Qualifications

• 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.

Responsibilities

• 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

Skills

Java

Spring Boot

React

TypeScript

SQL Server

REST APIs

Testing (JUnit/WireMock/Vitest)

Mentoring

Tools

Docker

Kubernetes

GitLab CI

OpenAPI-first

AWS

Job description

Daxko builds software for fitness, wellness, and community organizations, enabling member management, payments, and engagement.

This role combines legacy modernization with modern product development across a multi-generation codebase, including backend APIs, frontend UX, and deployment pipelines.

You'll work in a hybrid setup with in-person collaboration one day a week and remote work otherwise, contributing to tests, reviews, and engineering patterns across the stack.