Senior Python Developer Jobs in O Fallon, MO (NOW HIRING)

SR. PYTHON DEVELOPER
This position is based out of our St Louis, MO office

About ArchKey

ArchKey is one of the nation’s largest privately held specialty trade installation and integrated facility service companies. We are a leader in designing, building and maintaining electrical, technologies and specialty systems. We’re the POWER behind making the improbable possible.
We’re electrifying the nation, energizing the future and bringing communities to life like never before. What we do today shapes the vision of tomorrow. Our work impacts lives long after the building is done. This means we are committed to building in ways that are not just technologically advanced, but sustainable, scalable and equitable by all. We’re not just energizing infrastructure, we’re energizing careers, communities, and the future.

Made up of the brightest minds in the industry, our team is our greatest asset bringing knowledge, skills, and experience to every project. This is more than a call to join us, it’s an invitation to be part of a visionary journey, to grow with us as we scale.

About the Position

The Senior Python Developer is responsible for designing, developing, and maintaining complex, scalable Python applications and systems. This role provides technical leadership, mentors development team members, and drives architectural decisions that support business operations and innovation. The Senior Python Developer ensures all solutions align with company policies, procedures, objectives, and regulations

Our Ideal Candidate

• Designs, develops and maintains Python applications
• Is a Full-Life Cycle Python Developer
• Is able to provide Technical and Design Leadership

Day in the Life

• Designs, develops, and maintains scalable Python applications, APIs, and microservices using best practices and modern design patterns.
• Establishes and maintains enterprise-level Python development standards and enforces coding conventions.
• Provides architectural leadership, guiding system design and technology selection.
• Translates Business Requirements Documentation (BRD) into technical specifications and solution designs.
• Provides accurate level-of-effort estimates and contribute to project planning and roadmap discussions.
• Drives successful project delivery on time and within budget while maintaining high-quality standards.
• Writes clean, efficient, well-documented, and maintainable code.
• Conducts thorough code reviews to ensure quality, performance, security, and adherence to standards.
• Designs and implements RESTful APIs with appropriate authentication, versioning, validation, and error handling.
• Implements automated testing strategies, including unit, integration, and end-to-end tests.
• Builds and maintains CI/CD pipelines to support reliable and efficient deployments.
• Optimizes application performance and troubleshoots complex production issues.
• Ensures adherence to security best practices, data protection regulations, and secures coding standards.
• Collaborates with cross-functional teams to deliver effective technical solutions.
• Mentors and supports developers to strengthen team capabilities and technical excellence.
• Promotes continuous improvement in development processes, tools, and team practices.
• Contributes to documentation, knowledge sharing, and technical best practices across the organization.
• Consistently makes decisions in an attentive and safe manner to ensure the safety and health of self and others.
• Utilizes LEAN concepts or other continuous improvement methodologies to ensure the most efficient operations, processes, and activities.
• Promotes and models the Company mission, vision and values through exercising sound and ethical business practices, championing all elements of diversity, equity, and inclusion (DEI) and providing high quality services and programs as they relate to clients, subcontractors, co-workers, suppliers, and the public.

Minimum Qualifications

• Required Education, Experience and Skills
• Bachelor’s degree in Computer Science, Software Engineering, Information Systems, or a related field; or equivalent professional experience.
• 5-7 years of professional software development experience.
• 3+ years of hands-on Python development experience in production environments.
• Proven experience designing and implementing RESTful APIs and microservices architectures.
• Experience working in Agile environments (Scrum or Kanban).
• Expert-level proficiency in Python 3.x, including deep knowledge of language features, best practices, and design patterns.
• Strong experience with Python web frameworks (Django, Flask, FastAPI, or similar).
• Experience with relational databases (PostgreSQL, MySQL, SQL Server) and NoSQL databases (MongoDB, Redis).

• Experience with Git-based workflows and CI/CD tools (GitHub Actions, Jenkins, or similar).
• Hands-on experience with containerization (Docker) and orchestration platforms (Kubernetes).
• Experience with cloud platforms (AWS, Azure, or GCP) and cloud-native development practices.
• Knowledge of asynchronous programming, event-driven architectures, and message queues.
• Strong experience with testing frameworks (pytest, unittest) and test-driven development (TDD).
• Familiarity with performance optimization, profiling, and scalability strategies.
• Strong analytical and problem-solving abilities with attention to detail.
• Excellent written and verbal communication skills.
• Demonstrated leadership and mentorship experience.
• Ability to work independently and collaboratively in a team environment.
• Strong organizational skills with the ability to manage multiple priorities in a deadline-driven setting.
• Experience with data engineering tools and ETL processes preferred.
• Familiarity with machine learning frameworks (TensorFlow, PyTorch, scikit-learn) is a plus.
• Experience with front-end technologies (React, Vue.js, JavaScript) is desirable.
• Knowledge of application security testing and secure architecture principles is helpful.
• Contributions to open-source projects or technical publications is a plus.
• Relevant certifications (e.g., AWS Certified Developer, Python certifications) preferred.

Travel

• Occasional travel may be required.

Benefits

At ArchKey Solutions, our benefits package includes competitive health insurance options (medical, dental, and vision), a robust 401(k) retirement savings plan with employer match, paid time off and holidays, and access to wellness programs. Additionally, we offer professional development opportunities, tuition reimbursement, and employee assistance programs to support your growth and well-being. We ensure that our benefits are designed to promote the health, security, and work-life balance of our employees. Additional information is available at Archkey.com.

Legal & Fraud Disclaimer

All qualified applicants will receive consideration for employment without regard to race, color, religion, sex, sexual orientation, gender identity, national origin, disability, or status as a protected veteran. We are an Affirmative Action, Equal Opportunity Employer. ##MO1-10

 Beware of fraudulent job postings. ArchKey Solutions only communicates through official channels. All official communication will come from an @archkey.com email address and we will never ask for financial information, payments, or personal details outside of the standard hiring process. To confirm the legitimacy of a job, visit our careers page or reach out to a member of our Talent Acquisition team.