Senior Backend Engineer

AdCellerant•Denver, CO

3d•$135,000 - $165,000•Hybrid

About The Position

AdCellerant is an award-winning tech-enabled services company that has brought Madison Avenue-level digital marketing solutions to Main Street businesses since 2013. We help local marketers, media companies, agencies, and channel sales organizations leverage our proprietary advertising software platform, Ui.Marketing. We are looking for a highly skilled, self-directed Senior Backend Engineer with a strong polyglot mindset. Our ecosystem relies on both Node.js and Java. We need a versatile engineer who can confidently navigate and contribute to multiple codebases. If you have deep expertise in one with a working knowledge of the other, we want to talk to you. You won't just be writing code; you will take full ownership of complex technical challenges from conception to deployment. We are specifically looking for a forward-thinking engineer who smartly leverages AI coding assistants. You should know how to use AI to rapidly context-switch between projects or languages, accelerate development, translate concepts across stacks, and automate the mundane so you can focus on high-level architecture.

Requirements

5+ years of professional backend software development experience.
Languages & Frameworks: Deep, expert-level knowledge in at least one of our core languages, with strong professional capability in the other: Node.js (Preferred): TypeScript, NestJS, Express, or Fastify. Java: Modern Java, Spring Boot, or similar frameworks.
Polyglot Mindset: Demonstrated ability and willingness to learn new languages and frameworks quickly. You view languages as tools, not religions.
AI Tooling Fluency: Proven experience using AI coding assistants and prompt engineering to improve daily output, reduce technical debt, and bridge knowledge gaps when working outside your primary language.
Databases: Strong experience with relational databases (e.g., PostgreSQL, MySQL) and NoSQL databases (e.g., Redis, Elasticsearch).
Cloud & DevOps: Solid understanding of cloud platforms (AWS, GCP, or Azure), containerization (Docker, Kubernetes), and modern CI/CD pipelines.
Autonomy: Demonstrated ability to thrive in a highly autonomous environment, managing your own time and delivering on complex projects without micromanagement.
Currently legally authorized to work in the United States on a full-time basis.

Nice To Haves

Experience building, scaling, and communicating between event-driven microservices written in different languages.
Previous experience integrating AI APIs (OpenAI, Anthropic) into production applications.
Contributions to open-source projects or a portfolio showcasing independent, multi-language project execution.

Responsibilities

Autonomous Execution: Architect, build, and maintain robust backend services across both Node.js and Java environments. Take full ownership of features and microservices with minimal oversight.
System Architecture: Design scalable, highly available backend architectures and APIs (GraphQL, REST) that integrate seamlessly with frontend applications and diverse backend microservices.
Database Management: Design and optimize database schemas (SQL and NoSQL) to ensure data integrity and high performance across all services.
Code Quality & Mentorship: Maintain high standards of code quality through code reviews and automated CI/CD pipelines. Champion a polyglot culture and share your knowledge of workflows with the broader engineering team.
Problem Solving: Proactively identify performance bottlenecks and security vulnerabilities, implementing effective solutions independently.
AI-Driven Context Switching: Actively utilize AI development tools (such as GitHub Copilot and Cursor) to accelerate coding, rapidly adapt to unfamiliar design patterns in secondary languages, and translate logic between Node.js and Java ecosystems.