Top Senior Backend Engineer Jobs in Denver & Boulder, CO

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.

Design, build, and improve scalable backend systems that collect hard-to-access OSINT; build pipelines and ETL for messy data; collaborate with product and mission teams; mentor engineers and ensure reliable data delivery for DoD workflows.

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.

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.

Design, build, and operate resilient backend services for dynamic video packaging, manifest generation (HLS/MPEG-DASH), DRM integration, and high-performance server-side ad insertion. Own production reliability, incident response, observability, and performance optimization while integrating AI-driven diagnostics and automation to scale streaming delivery for millions of concurrent viewers.

The Senior Software Engineer will design and develop scalable applications, enhance DevOps practices, and drive continuous improvement within infrastructure and systems.

Design, enhance, and scale the ClickPipes data onboarding platform while improving infrastructure, deployment pipelines, and operational processes in a cloud environment.

As a Senior Backend Engineer, you will build APIs and integrations, develop fault-tolerant systems, mentor engineers, and ensure code quality.

Founding engineering role to architect and build core backend platform components. Design and implement scalable, distributed Java/JVM systems, apply solid testing and CI/CD practices, collaborate with CEO/CTO, and work in an agile early-stage fintech startup environment.

Design and scale backend systems, lead architecture discussions, develop APIs, and ensure system reliability and security, while mentoring others.

Build and maintain automated ETL/ELT data pipelines, improve data quality and monitoring, optimize Postgres and BigQuery schemas and queries, develop internal tooling, support data governance (HIPAA), participate in on-call rotation, and collaborate across engineering teams to scale data systems.

As a Senior Backend Engineer at Akkio, you'll design and build backend systems for an AI-driven platform, lead projects, mentor junior engineers, and optimize cloud infrastructure.

Build and optimize Nitro node software powering Arbitrum: improve transaction execution, state management, networking, throughput, performance, reliability, observability, and security. Design and operate distributed systems at scale and add runtime capabilities such as Stylus/WASM for smart contract execution.

As a Senior Backend Engineer at Offchain Labs, you'll tackle complex distributed systems challenges, optimizing performance and contributing to the security and scalability of blockchain technology.

Design and build API tooling, integrations, and mission-critical distributed platform services. Own API Gateway integrations and service lifecycles, drive API governance, improve shared services, and support platform capabilities powering ClickUp's AI initiatives (Brain and Agents). Collaborate across teams in an agile environment to accelerate product development.

Design, scale, and optimize ClickUp's search infrastructure using OpenSearch/Elasticsearch. Improve relevance, speed, and real-time indexing, build vector search capabilities, create evaluation frameworks, and collaborate with AI/backend/product teams to integrate and troubleshoot search at scale.

Design and implement durable, fault-tolerant AI orchestration and backend systems using Temporal and agentic ReAct patterns. Deliver features end-to-end with testing, CI/CD, monitoring, and observability; mentor engineers and collaborate with cross-functional teams to translate legal workflows into reliable AI-powered features.

As a Senior Backend Engineer, you will design and deliver complex systems, ensuring reliability, security, and performance while mentoring junior engineers and collaborating across teams.

Build and operate distributed systems for profile ingestion and queries in Pyroscope. Lead projects end-to-end, participate in on-call rotations, mentor teammates, design for reliability and performance, and work closely with customers and Grafana Cloud teams.