Sr. Software Engineer

Who We Are

As the largest private-sector power producer in the world and the nation's largest producer of clean and reliable energy, Constellation is focused on our purpose: lighting the way to a brilliant tomorrow for all. We have been the leader in clean energy production for more than a decade, and we are cultivating a workplace where our employees can grow, thrive, and contribute. Now integrated with Calpine, our portfolio includes 55 gigawatts of capacity from nuclear, natural gas, geothermal, hydro, wind and solar facilities, with the generating capacity to power the equivalent of 27 million homes.

Our culture and employee experience make it clear: We are powered by passion and purpose. Together, we're creating healthier communities and a cleaner planet, and our people are the driving force behind our success. At Constellation, you can build a fulfilling career with opportunities to learn, grow and make an impact. By doing our best work and meeting new challenges, we can accomplish great things. Join us in meeting the country's energy needs today and tomorrow.

Total Rewards

Constellation offers an extensive selection of benefits and rewards to help our employees thrive professionally and personally. We provide competitive compensation and a wide-range of benefits that support both employees and their families, helping them prepare for the future. In addition to highly competitive salaries, eligible employees are offered a bonus program, 401(k) with company match, employee stock purchase program; comprehensive medical, dental and vision benefits, including robust wellbeing programs; disability and life insurance benefits; paid time off for vacation, holidays, and sick days; and much more.

Expected salary range of $117,900 to $131,000, varies based on experience, along with comprehensive benefits package that includes bonus and 401(k).

Primary Purpose of Position

Constellation/Calpine is seeking a Full‑Stack / Backend Developer to design, build, and maintain enterprise‑grade APIs and Azure API Management (APIM) layers that securely expose data from SQL databases and AI/ML models . This role will focus on building scalable, secure, and reusable APIs that support internal applications, analytics platforms, and AI‑powered solutions across Constellation/Calpine.

Primary Duties and Accountabilities

• Engage with business partners to gather information, analyze requirements and deliver practical, efficient and cost-effective solutions that satisfy business needs.

• Write product specifications and design documentation for assigned system components.

• Design, develop, and review complex code and technical architecture to ensure alignment with functional and technical specifications; deliver solutions including web, mobile, full stack, and integration applications across on premises and cloud environments; develop automated unit and UI tests.

• Lead engineering team and provide oversight for less experienced engineers; Stay on top of latest technologies and trends.

• Using error reports, establish priorities and assign out bugs to relevant team members for resolution.

• Support development of version control principles (e.g. Git and working within an agile environment), CI/CD pipeline and various automations.

• Ensure all risks and issues that affect the project are captured following set process and are actioned appropriately.

• Enhance knowledge of and compliance with preferred technologies, methodologies, standards and policies.

• Maintain and enhance technical knowledge and business acumen within the relevant discipline or function.

• Provide IT teams and business personnel with technology solutions by weighing advantages of technology trends, market availability of products, risks and benefits of technology to meet business/IT needs.

• Participate in IT architecture review and standards setting.

• Assist in the development of white papers, conducting presentations as needed to explain why a technology is being recommended by IT.

• Deliver production REST APIs that expose enterprise SQL data, managed and published via Azure APIM (gateway + developer portal).

• Build secure, high‑performance APIs and backend services integrating Azure SQL Database , Databricks , and enterprise data stores with Azure OpenAI , custom ML models , and RAG pipelines —optimizing SQL/stored procedures and enabling consumption of structured and unstructured data for AI‑driven applications.

• Apply Constellation/Calpine security standard , data protection and implement observability ( logging/tracing ) and reliability practices ( HA/DR, governance ).

Minimum Qualifications

• Bachelor's degree in Computer Science, Engineering, Mathematics, or a related technical field with at least 5 years of relevant experience, or, in the absence of a degree, a minimum of 9 years of relevant experience.

• Demonstrated ability to lead small to medium teams in delivering software solutions

• Demonstrated strong software development capabilities coupled with the ability to work under tight deadlines

• Teamwork and self-motivation skills to achieve success in a rapidly evolving environment

• Excellent communication and presentation skills, with the ability to translate technical concepts for diverse audiences

• Knowledge of operating systems such as Windows or cloud platforms such as Azure, Amazon Web Services, or Google Cloud

• Strong knowledge of software development languages, such as Python, C#, JavaScript, Node.js, .NET, HTML or Angular

• Strong knowledge of SQL or NoSQL databases such as Oracle, SQL Server, Cosmos DB, MySQL, Redis, or Splunk

• Strong understanding of advanced programming concepts, data structures, and algorithms

Preferred Qualifications

• Proven expertise in architecting and developing robust, cloud-native applications on Microsoft Azure, utilizing .NET/C# and Node.js backend frameworks. Demonstrated deep understanding of microservices architecture and design principles to deliver scalable, high-performance enterprise solutions.

• Experience designing and building enterprise APIs and delivering through APIM with strong relational database skills.

• Experience with Azure OpenAI or GenAI solutions by elevating Enterprise data from data platforms, analytics.

• Experience in integrating backend services with AI/ML models or AI platforms.

• Strong understanding of cloud native design principles on Microsoft Azure .

• Azure Components, SQL Server, Azure DevOps (Repos, Pipelines), Azure Key Vault, Application Insights

• Experience working in regulated or enterprise environments

• Strong problem‑solving and analytical abilities

• Ability to work across engineering, data, and AI teams

• Clear communicator with a focus on collaboration

• Ownership mindset and attention to operational excellence

Constellation is proud to be an equal opportunity employer and employees or applicants will receive consideration for employment without regard to: age, color, disability, gender, national origin, race, religion, sexual orientation, gender identity, protected veteran status, or any other classification protected by federal, state, or local law.