Senior Software Engineer- Full Stack

Daxko•Centennial, CO

9d•Hybrid

About The Position

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.

Requirements

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 Haves

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

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