• Design and develop scalable web applications using ASP.NET Core, Vue.js with Quasar framework, and MySQL. • Implement robust services and APIs to support the front-end architecture. • Manage and optimize application data using MySQL. • Integrate and manage message-oriented middleware systems such as RabbitMQ. • Work with AWS cloud services to deploy and maintain applications. • Provide leadership and guidance to mid-level developers, delegating tasks and responsibilities. • Collaborate with project managers to plan, execute, and deliver software projects on time and within budget. • Ensure code integrity, quality, and maintainability by conducting code reviews and optimizing performance.

Title: API Developer Location: Denver United States Job Description: Job#: 3027729 Job Description: The VA Lighthouse Program is a U.S. Department of Veterans Affairs initiative to modernize and streamline access to VA data and services through secure, reliable, scalable application programming interfaces (APIs), improving how veterans, partners, and internal teams access critical information. The AI & Engineering team supports the VA Lighthouse platform to accelerate digital delivery, modernize technology and operations, and drive measurable improvements for public sector clients through collaboration, innovation, and continuous improvement. As the API Developer you are responsible for designing, developing, and maintaining Application Programming Interfaces (APIs) that enable communication between different software systems. Below are the typical roles and responsibilities for this position: - Define and document API specifications, endpoints, data models, and protocols - REST, GraphQL. - Build and implement APIs using programming languages and frameworks such as Java, Python, Ruby and .net. - Ensure seamless integration of APIs with internal and external systems, applications, and third-party services. - Write unit, integration, and end-to-end tests for APIs. Debug and resolve issues to ensure reliability and performance. - Create and maintain clear, comprehensive documentation for API consumers, including usage examples and best practices. - Implement authentication, authorization, encryption, and other security best practices to protect data and services. - Monitor and optimize API performance, scalability, and reliability. - Manage API versions and ensure backward compatibility as APIs evolve. - Work closely with front-end and back-end developers, architects, QA engineers, and other stakeholders to deliver robust - solutions. - Provide ongoing support, troubleshoot issues, and implement enhancements based on user feedback Qualifications and Skills: - Java, SpringBoot & SpringBatch framework - GitHub, Jaeger, GitHub Actions, Git Releases - mySQL - Oracle - RDS - Document DBs (DynamoDB, MongoDB) - Ruby - Python - AWS Cloud - Backstage.io - Open API - OpenTracing - Docker, Kubernetes, Helm, - Familiarity with VA Lighthouse APIs Apex Systems is a world-class IT services company that serves thousands of clients across the globe. When you join Apex, you become part of a team that values innovation, collaboration, and continuous learning. We offer quality career resources, training, certifications, development opportunities, and a comprehensive benefits package. Our commitment to excellence is reflected in many awards, including ClearlyRated's Best of Staffing in Talent Satisfaction in the United States and Great Place to Work in the United Kingdom and Mexico. Apex uses a virtual recruiter as part of the application process. Click here for more details. Apex Benefits Overview: Apex offers a range of supplemental benefits, including medical, dental, vision, life, disability, and other insurance plans that offer an optional layer of financial protection. We offer an ESPP (employee stock purchase program) and a 401K program which allows you to contribute typically within 30 days of starting, with a company match after 12 months of tenure. Apex also offers a HSA (Health Savings Account on the HDHP plan), a SupportLinc Employee Assistance Program (EAP) with up to 8 free counseling sessions, a corporate discount savings program and other discounts. In terms of professional development, Apex hosts an on-demand training program, provides access to certification prep and a library of technical and leadership courses/books/seminars once you have 6+ months of tenure, and certification discounts and other perks to associations that include CompTIA and IIBA. Apex has a dedicated customer service team for our Consultants that can address questions around benefits and other resources, as well as a certified Career Coach. You can access a full list of our benefits, programs, support teams and resources within our 'Welcome Packet' as well, which an Apex team member can provide. Employee Type: Contract Remote: Yes Location: Denver, CO, US Job Type: Date Posted: March 25, 2026 Pay Range: $50 - $75 per hour Similar Jobs - Senior API Engineer - API Governance Lead - API Governance Lead - Integration/API Engineer - Software Engineering Consultant (Java/React & API Development) - Charlotte, NC

Role Description We're seeking a Backend Engineer to design, build, and scale the core services powering our client's platform. You'll work across a modern, service-based architecture to deliver reliable, performant systems that power yield products for some of the largest names in DeFi and fintech. The ideal candidate is a hands-on engineer with a strong sense of ownership, comfortable navigating ambiguity, and experienced in taking products from concept to production. You'll work 70–80% in code, contributing directly to system design, architecture, and implementation. - Design and build scalable backend systems powering API and internal services - Own projects end-to-end — from scoping and design to implementation, testing, and production delivery - Collaborate with product and infrastructure teams to turn technical debt into modern, maintainable, and highly available systems - Write clean, well-tested code, and maintain strong CI/CD hygiene - Deploy, monitor, and scale services in production using modern cloud tooling (AWS, GCP, or similar) - Contribute to system design discussions covering performance, reliability, and data architecture - Participate in on-call rotations and incident response for production systems - Continuously identify and drive improvements in system reliability, observability, and performance Qualifications - 6+ years of professional backend engineering experience - Proven experience delivering production systems end-to-end (scoping design implementation production) - Strong programming skills in Python or another modern backend language (e.g., Go, Rust, Java, C++) - Solid understanding of REST APIs, relational databases (Postgres or MySQL), and service-based architectures - Experience with version control (Git), unit/integration testing, and CI/CD pipelines - Familiarity with cloud environments (AWS, GCP, Azure) and containerization (Docker, Kubernetes) - Experience participating in an on-call rotation or owning production systems - Demonstrated ability to design scalable systems and refactor legacy components Benefits - Health Coverage - We offer medical, dental, and vision coverage for employees. For international contractors, we work closely to ensure access to appropriate local or global health coverage. - Flexible Time Off - We don't track vacation days. Take the time you need to rest and recharge, we trust you to manage your schedule. - Remote-First by Design - Our team spans time zones and geographies. We work async, with a focus on autonomy over micromanagement. - Parental Leave - Paid leave is available for new parents, whether you're the primary or secondary caregiver. - Learning & Development - We offer stipends to support ongoing learning - whether it's a course, a conference, or something else that helps you grow.

• Build and maintain backend services and APIs in Python • Design and ship AI features using LLMs and modern ML techniques • Implement retrieval workflows (RAG, embeddings, vector search) • Take AI systems from prototype to production and iterate based on real usage • Work closely with other engineers and stakeholders to make good technical trade-offs • Help keep our systems clean, reliable, and easy to extend