Sr. Java Developer

Mavensoft Technologies, LLC; Denver, Northern (CO, KY); Hybrid; USD 120,000 - 180,000; Part time

Job summary

Mavensoft Technologies, LLC in Denver seeks an experienced Sr. Java Developer to design, develop, and maintain Java-based applications, REST APIs, and cloud services, with a strong focus on Java 21, Spring Boot, and AWS.

This 7‑month W2 contract is hybrid—onsite Tuesdays, remote otherwise. You will contribute to CI/CD pipelines, Terraform infrastructure, GitLab workflows, and code reviews using IntelliJ IDEA, delivering reliable, well-documented software.

Qualifications

• Strong experience developing Java applications.
• Experience with Java 21 or newer.
• Experience designing, building, and consuming REST APIs.

Responsibilities

• Design, develop, test, and maintain Java-based applications using Java SDK 21.
• Build and enhance applications with Spring Boot and the Spring Framework.
• Develop and maintain REST APIs and JSON-based integrations.
• Work with AWS services including ECS, API Gateway, and DynamoDB.
• Contribute to source control and development workflows using GitLab.
• Build, maintain, and troubleshoot GitLab CI/CD pipelines.
• Participate in architecture decisions, code reviews, and deployment practices.
• Support infrastructure-as-code efforts, particularly using Terraform.
• Use IntelliJ IDEA as the primary development environment.
• Apply sound software engineering practices including maintainable code, testing, and documentation.

Skills

Java development

Spring Boot

REST APIs

AWS

GitLab CI/CD

Terraform

IntelliJ IDEA

AI-assisted tools

Tools

GitLab

IntelliJ IDEA

Job description

Title: Sr. Java Developer
Location: Denver, CO – Hybrid ,MST (Candidate Must Be Local )
Hybrid, 1 day On-site on Tuesdays. Remote work rest of days
Duration: 7 Months – W2 Contract

Job Description

Our Client is seeking an experienced Java Developer Contractor to support the design, development, and maintenance of web applications, backend services, and cloud-based solutions.

The ideal candidate will be comfortable working across the Java/Spring ecosystem, building REST APIs, integrating with AWS services, and contributing to modern CI/CD-driven development workflows. The candidate should be hands-on, pragmatic, able to work independently, and comfortable collaborating with technical and business stakeholders.

Responsibilities

• Design, develop, test, and maintain Java-based applications using Java SDK 21.
• Build and enhance applications using Spring Boot and the Spring Framework.
• Develop and maintain REST APIs and JSON-based integrations.
• Work with AWS services including ECS, API Gateway, and DynamoDB.
• Contribute to source control and development workflows using GitLab.
• Build, maintain, and troubleshoot GitLab CI/CD pipelines.
• Participate in application architecture, implementation decisions, code reviews, and deployment practices.
• Support infrastructure-as-code efforts, particularly using Terraform.
• Use IntelliJ IDEA as the primary development environment.
• Apply sound software engineering practices including maintainable code, testing, documentation, and operational awareness.
• Leverage AI-assisted coding tools where appropriate to improve productivity and code quality.

Required Qualifications

• Strong professional experience developing applications with Java.
• Experience with Java 21 or recent versions of the Java SDK.
• Solid experience with Spring Boot and Spring-based application development.
• Experience designing, building, and consuming REST APIs.
• Strong working knowledge of JSON and API integration patterns.
• Experience with Git-based source control, preferably GitLab.
• Experience with CI/CD pipelines, preferably GitLab CI/CD.
• Practical experience developing, deploying, or supporting applications in AWS.
• Ability to work independently, communicate clearly, and deliver high-quality work in a contractor capacity.

Preferred Qualifications

• Experience with Thymeleaf.
• Hands-on experience with Amazon ECS, API Gateway, and DynamoDB.
• Familiarity with Terraform or other infrastructure-as-code tools.
• Professional experience using IntelliJ IDEA.
• Familiarity with AI-assisted development tools such as Claude Code, GitHub Copilot, Cursor, or similar tools.
• Experience troubleshooting cloud deployments, application logs, build pipelines, and environment-related issues.
• Understanding of secure coding practices and cloud application security concepts.