Senior Developer

Reflexive Concepts, LLC; Maryland; On-site; USD 140,000 - 190,000; Full time

Job summary

Reflexive Concepts, LLC seeks a Senior Developer to lead a small team delivering a mission-critical Enterprise Support Services application. You will translate customer needs into technical requirements, build responsive web interfaces, and integrate with RESTful services.

You will apply Python frameworks (Django, FastAPI, or Flask) and modern JavaScript (React.js, Vue.js), maintain databases (PostgreSQL preferred), and participate in CI/CD with Docker, GitLab, and Linux-based deployments.

Qualifications

• Active TS/SCI security clearance with Full Scope (FS) Polygraph.
• Bachelor's degree in a technical discipline and 12 years of software development/engineering experience (16 years may substitute for degree).
• Experience with JavaScript and modern front-end frameworks (React.js and Vue.js).
• Experience with REST APIs.
• Experience with Python full-stack development (Django, FastAPI, or Flask) with React.js or Vue.js and RESTful API integrations.
• Unit testing experience.

Responsibilities

• Lead a small development team supporting sustainment and continuous enhancement of a mission-critical Enterprise Support Services application.
• Serve as senior technical point of contact between the team and the customer; translate requirements into technical solutions.
• Engage with stakeholders to understand business needs and build alignment for proposed solutions.
• Build intuitive, responsive web interfaces connected to robust data retrieval and storage.
• Apply hands-on Python with Django/FastAPI/Flask to deliver scalable applications.
• Apply hands-on JavaScript with React.js and Vue.js to deliver high-quality user interfaces.
• Integrate backend services through RESTful APIs to support data flow and application functionality.
• Leverage full-stack skills across Python backend and JS frontend architectures for end-to-end solutions.
• Work with PostgreSQL; some Oracle/SQL Server experience is a plus.
• Support upgrades and implement code enhancements for performance and maintainability.
• Develop efficient data retrieval solutions for dynamic views.
• Diagnose, troubleshoot, and resolve defects to maintain stability.
• Design, build, and deploy Docker containerized apps on Linux servers.
• Conduct unit testing to validate reliability and feature accuracy.
• Collaborate in Git/GitLab workflows and CI/CD pipelines.
• Demonstrate ownership mindset and provide technical leadership.
• Participate in Agile sprint planning and backlog grooming.

Skills

JavaScript

Python

REST APIs

React.js

Vue.js

Docker

Git/GitLab

Linux

Education

Bachelor's degree in a technical discipline

Tools

Docker

Git/GitLab

CI/CD pipelines

Job description

Reflexive Concepts is seeking a skilled Senior Developer to join our team!

Duties and Responsibilities:

• Lead a small, collaborative development team supporting the sustainment and continuous enhancement of a mission-critical Enterprise Support Services application that enables a key operation.
• Serve as a senior technical point of contact between the development team and the customer, helping translate customer needs into clear, actionable technical requirements and solutions.
• Engage with customers and stakeholders to understand business needs, communicate technical approaches, refine requirements, and build alignment and buy-in for proposed solutions.
• Build intuitive, responsive web interfaces backed by robust data retrieval and storage capabilities.
• Apply hands‑on expertise with modern Python frameworks, such as Django, FastAPI, or Flask, to deliver scalable, secure, and performant applications.
• Apply hands‑on expertise with modern JavaScript and front‑end frameworks, specifically React.js and Vue.js, to deliver high‑quality user interfaces and dynamic, client‑side application features.
• Integrate backend services through RESTful APIs to support seamless data flow and reliable application functionality.
• Leverage full‑stack development skills across Python backend services and modern JavaScript front‑end architectures to deliver scalable, end-to-end solutions.
• Demonstrate strong experience with relational database management systems (RDBMS), with primary expertise in PostgreSQL and secondary experience with Oracle and SQL Server.
• Translate complex business requirements into effective enhancements within existing database structures and application logic.
• Support and execute application upgrades while implementing code enhancements that improve performance, maintainability, and long‑term sustainability.
• Develop efficient data retrieval solutions that power user‑friendly displays and dynamic application views.
• Diagnose, troubleshoot, and resolve application defects to help maintain system stability and a positive user experience.
• Design, build, and deploy Docker containerized applications to Linux servers.
• Conduct thorough unit testing to validate software reliability, performance, and feature accuracy.
• Collaborate within Git/GitLab workflows and contribute to CI/CD pipelines that enable smooth, automated delivery of application updates.
• Bring a proactive, ownership‑oriented approach to problem‑solving, provide technical leadership to the development team, and demonstrate a strong willingness to take on new challenges and learn emerging technologies.
• Actively contribute in an Agile environment by participating in sprint planning, backlog grooming, and iterative development cycles that deliver continuous value.

Required Qualifications:

• Active TS/SCI security clearance with Full Scope (FS) Polygraph.
• A bachelor's degree in a technical discipline and twelve (12) years of experience in software development/engineering. Sixteen (16) years of experience in software development/engineering may be substituted in lieu of a degree.
• Working knowledge of JavaScript and modern front‑end frameworks, specifically React.js and Vue.js.
• Experience with REST APIs.
• Experience with modern Python full-stack development, utilizing Python web frameworks (such as Django, FastAPI, or Flask) paired with modern front‑end frameworks (React.js or Vue.js) and RESTful API integrations.
• Unit testing experience.
• Git/GitLab experience with CI/CD.
• Experience with Docker.
• Working knowledge of Linux.
• Working knowledge of Agile software development processes.

Desired Skills:

• Extensive experience in agile development, including running sprint planning sessions, managing sprint backlogs, and delivering high‑quality results on time.
• A background in developing enterprise‑level applications with a focus on scalability, security, and performance.
• Experience managing systems in a virtual hosting environment, including AWS.
• Familiarity with CI/CD.