Top Senior Backend Engineer Jobs in Denver & Boulder, CO

Design, build, test, and maintain backend services and APIs for an insurance platform. Integrate external services and data providers, improve system stability, performance, and scalability, participate in architecture discussions, mentor teammates, and support internal tooling and deployment practices.

Design and implement secure, scalable backend services for speech inference and audio processing. Optimize networking, transcoding, latency, memory, and distributed compute orchestration. Measure and improve system performance, debug complex networking/scheduling/HPC issues, customize services for customers, and partner with Product to deliver features end-to-end.

As a Senior Backend Engineer at DuckDuckGo, you'll lead backend projects, mentor engineers, and develop AI-enhanced features for the company's privacy-centric product line.

The Senior Backend Engineer will develop the Payroll product, overseeing the entire development cycle from design to deployment, in a microservices architecture.

Design, build, and maintain scalable backend services and APIs for commerce workflows using Python/Django. Improve reliability, performance, and observability, operate AWS deployments, work with PostgreSQL and event-driven architectures (SNS/SQS), modernize legacy systems, and support CI/CD, testing, and production troubleshooting.

The Senior Backend Engineer II will design, build, and maintain backend services for financial workflows, collaborating with product and engineering teams to enhance system reliability and performance.

Develop, maintain, and evolve a high-throughput, low-latency US sports trading platform. Build scalable microservices on GCP with Kubernetes using Go or Rust. Ensure resilience during peak events, contribute to architecture, mentor junior engineers, collaborate with stakeholders, and adopt CI/CD, IaaS, concurrency debugging, and in-house AI technologies to deliver reliable global services.

Build, operate, and extend data platform and application-layer services enabling secure, self-service data applications at scale. Implement provisioning, CI/CD, access control, integrations, observability, automation, and incident response while contributing to semantic layer and AI-ready tooling roadmaps.

The Senior Backend Engineer will enhance data integration infrastructure, manage internal systems, and collaborate with teams to execute engineering tasks for growth initiatives.

As a Senior Software Engineer, you'll own backend systems, mentor team members, and collaborate with product and design to build user-focused solutions.

The Backend Software Engineer will develop data ingestion pipelines, implement observability tools, and provide technical support while improving team collaboration.

The role involves developing high-scale, distributed backend systems, collaborating with teams, and optimizing products through A/B testing.

Build and own the graph layer and RAG architecture enabling agent reasoning over full patient context. Select graph DBs, design query patterns, and ensure temporal coherence. Implement event-driven Kafka pipelines for auditable, immutable agent workflows and enforce ReBAC permissions. Prioritize safety and scalable AI-assisted workflows, participate in spec and plan reviews, and drive architecture decisions.

Design and implement data infrastructure for Oura's Context Hub. Responsibilities include building data pipelines, defining data models, creating APIs, and ensuring system resilience in production environments.

Build, enhance, and maintain backend services and REST APIs in Go; develop ETL pipelines in Python; design reliable PostgreSQL-backed APIs; use AWS services (S3, Lambda, Step Functions, Glue) for data processing; write well-tested, secure code; support operations and maintenance; participate in code reviews and cross-functional Agile collaboration.

The Senior Back-End Developer builds and maintains server-side operations for cloud solutions, collaborating with teams to deliver software, support users, and document features.

Lead backend development to scale and harden API infrastructures, implement unit testing playbooks, optimize core algorithms, support migration from Supabase to a robust cloud provider, ensure system reliability and scalability, collaborate with frontend and DevOps, and integrate AI workflows and RPA where applicable.

The Senior Backend Engineer will lead client projects, build AI solutions, and develop technical standards while mentoring junior engineers.

Design, build, and optimize high-throughput, highly available backend services in Golang for 24/7 sports and prediction-market applications. Lead architecture decisions, implement features, diagnose and resolve high-concurrency bottlenecks, and provide high-tier operational support for real-time transactional systems.

The Senior Backend Engineer will develop financial technology solutions, focusing on transparency in consumer lending through modern API development and data analytics, while collaborating with various teams to enhance product offerings.

The role involves designing and expanding backend systems, mentoring engineers, and executing technical strategies to modernize architecture and improve system performance.

The Senior Backend Engineer will develop, test, and maintain scalable integrations, support cross-functional teams, and enhance developer experiences.

Design, build, and optimize scalable, secure backend services, APIs, and data pipelines to support thick-client desktop applications (e.g., Electron). Focus on performance, concurrency, data modeling, authentication/authorization, and integration with DevSecOps pipelines. Collaborate on schema design, code reviews, CI/CD, containerization, and secure communications in regulated environments.

Design, implement, and maintain scalable backend services primarily in Clojure; support and modernize legacy Node.js services; collaborate on cloud deployments, infrastructure-as-code, and deployment pipelines; ensure code quality through reviews and debugging; work with cross-functional teams to integrate services and improve reliability.

Design and build scalable backend systems, data pipelines, and cloud infrastructure. Own CI/CD, containerization, databases, and reliability; collaborate with tech leads to deliver secure, production-grade solutions for startups in a fully remote environment.