Top Senior Backend Engineer Jobs in Denver & Boulder, CO

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.

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.

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.

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

Build and improve frontend experiences for login, signup, OAuth, account security, and multi-user/org support. Contribute to migrating main views to React Native, design high-performance React/TypeScript UIs, collaborate with backend engineers and product teams, and write well-tested, reliable code to maintain low-latency user surfaces at scale.

The Senior Staff Software Engineer will architect Affirm's lakehouse analytics platform, lead data governance efforts, mentor engineers, and collaborate across teams to optimize data solutions using Snowflake and other big data tools.

Seeking a Senior Backend Engineer for a payment modernization project, focusing on API integrations, payment routing logic, and payment orchestration systems under the CTO's guidance.

The Senior Backend Engineer at Weave will design, build, and maintain scalable backend services and APIs, influencing architecture and outcomes while collaborating across teams to enhance healthcare technology.

Design, build, and scale event-driven, distributed backend systems in Python to extract and enrich metadata at massive scale. Lead architecture, mentor engineers, integrate ML/LLM components, optimize performance, and ensure observability and reliability across AWS-based pipelines.

Lead design and scaling of content ingestion, metadata, and processing systems. Build reliable pipelines handling messy formats, collaborate with ML, security, and product teams, mentor engineers, and drive platform and AI/LLM integration for content workflows and quality.

The Senior Back End Engineer will develop and enhance critical services, manage APIs, optimize application architecture, and mentor junior engineers.

As a Senior Platform Engineer at Greenbox Capital, you'll modernize the origination ecosystem, focusing on scalable services, API development, and system integration, requiring strong collaboration and technical leadership skills.

Lead design, build, and maintain provider integration infrastructure connecting to insurance carrier and partner APIs. Own end-to-end connector development, testing, validation against live traffic, and ongoing mapping/business rules. Define technical direction, scope projects, mentor engineers, perform code reviews, and drive operational excellence while collaborating cross-functionally to align engineering work with product goals.

The Senior Backend Engineer develops core product features in ETL and GraphQL, designs APIs, builds ETL pipelines, and collaborates with frontend teams.

As a Senior Backend Developer, you'll design and maintain high-volume pipelines and databases, implement ETLs for automated abuse-prevention, and develop monitoring solutions while collaborating with teams on safety systems.

The Senior Backend Engineer will lead AI-focused projects, optimize data pipelines, mentor juniors, and enhance customer support through innovative technologies.

The role involves back-end development using .NET Core and SQL, contributing to Jibble 2.0 API integrations, and collaborating with product and design teams.

Lead backend architecture and implementation for Java Spring microservices, validate and own AI-assisted code, mentor engineers, collaborate with product to deliver features, and drive technical excellence and scalable, test-covered systems.

As a Senior Backend Engineer, you'll develop and maintain the Dynamic Copay Engine's services, design pricing logic, and manage data integrations, focusing on backend systems for health insurance functionality.

Develop frontend features for mobile/web: quest storefront, user and creator dashboards, admin tools, marketing/sales features, and third-party integrations. Work in one-week Scrum sprints, contribute to architecture, use git/GitLab and AI-assisted coding tools, and collaborate on product development.