Top Backend Engineer Jobs in Denver & Boulder, CO

Design, build, test, and maintain backend services and APIs powering the insurance platform. Integrate payments, documents, and data providers, improve system stability, performance, and scalability, mentor team members, and participate in architectural decisions and agile ceremonies.

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.

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.

Develop, test, and improve the OT Security Platform as part of the Microsegmentation Product Team, ensuring high-quality software and architecture.

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 Staff Software Engineer will lead technical strategy, ensure system availability, and develop backend systems at scale, collaborating across teams to drive capacity modeling and operational quality.

Design and implement scalable backend services for payment and transaction workflows using Java. Own end-to-end features from data model and APIs to Angular frontends, improve reliability and performance, refactor legacy systems, troubleshoot production issues, and collaborate with product and design. Leverage AI-assisted development tools responsibly and share best practices across the team.

Design and implement Kotlin backend services and end-to-end systems for Toast POS device management. Lead technical designs, estimations, performance optimization, cross-team collaboration, and software quality practices including modern testing and observability. Mentor peers and drive product roadmap alignment with product, hardware, and QA stakeholders.

Lead and deliver quarterly goals for a backend team; guide engineers through ambiguous problems; collaborate with product, design, and analytics; identify and resolve project and technical issues; ensure operational availability and on-call readiness; set code and design quality standards; and mentor and develop team members.

Design, build, and operate backend systems for prediction markets, including order management, trade matching, settlement, and market resolution. Architect distributed, low-latency systems with strict financial correctness, lead multi-quarter technical projects, mentor engineers, and collaborate with Product, Compliance, and Risk to meet regulatory requirements.

Own architecture and delivery of core ledger and transaction processing systems. Design and build highly available, high-performance backend services, drive cross-team technical initiatives, establish platform standards, mentor engineers, and embed AI to improve operations and workflows.

Develop a platform for liquidity and loan collateralization. Responsibilities include building and integrating data pipelines, creating user experiences, and collaborating with teams for system design.

Design, build, and maintain automation tools and systems to deploy and manage cloud-based infrastructure. Collaborate with cross-functional teams to analyze requirements, implement APIs and database schemas, write automated tests, and contribute to architectural and automation strategies while emphasizing security and production stability.

Lead technical strategy and delivery for backend marketplace/search systems. Collaborate with PM, design, and analytics; own operational reliability, monitoring, on-call, testing, and runbooks; set code/design standards; drive major feature delivery and deprecations; mentor and develop engineering talent.

Design, implement, and optimize high-performance backend systems in Rust for an xOT security platform. Participate across the development lifecycle—debugging, testing, and performance tuning—while integrating relational and NoSQL data stores, microservices, third-party devices, and AI tools. Provide technical leadership, code review feedback, and promote secure, reliable, observable distributed systems.

Design, build, and maintain backend services powering Clerkie's platform. Improve reliability, performance, scalability, observability, and support feature development. Participate in technical design, cross-functional collaboration, documentation, and own projects end-to-end in a fast-moving startup environment.

Lead backend and full-stack work on the Payments team, building multi-gateway integrations (Stripe, PayPal), payment APIs, and customer payment UIs. Ensure secure, compliant (PCI-DSS) payment flows, reliability, observability, and scalability across AWS/Kubernetes microservices. Partner cross-functionally to design architecture, implement settlement/reconciliation, and maintain high availability.

Design, implement, and evolve complex backend features and architecture. Improve reliability, performance, and security at scale. Mentor engineers, participate in incident response, set backend standards, and integrate agentic AI into production workflows.

Own and evolve the Subscriptions and Payments backend: design APIs, integrate providers, improve reliability and scalability, lead architecture and code reviews, collaborate cross-functionally, and participate in on-call rotations.

Lead technical strategy and execution for a backend ledger team building highly available, audit-grade financial systems. Drive architecture, reliability, monitoring, on-call practices, code quality, cross-functional collaboration, and mentoring to ensure accurate, scalable ledger operations.

Design and implement backend and real-time features in the GitLab monolith for portfolio planning at scale. Optimize PostgreSQL performance, evolve APIs (GraphQL/REST), build capacity planning and work-item hierarchies, create proofs of concept, maintain automated tests, support safe rollouts with feature flags and observability, mentor contributors, and participate in on-call and production troubleshooting.

As a Staff Backend Engineer, you'll design and operate backend services, lead technical initiatives, ensure reliability, and mentor team members in a remote-first setup.

Maintain and improve GameChanger's backend API server and SDK. Implement API/SDK changes, improve developer ergonomics, optimize performance and scalability, design critical systems, document and mentor teammates, and participate in on-call rotation.

Build and operate high-throughput backend services powering AI agent orchestration, connector integrations, and real-time data pipelines. Design scalable core platform services, collaborate with ML, frontend, and product teams, implement infrastructure-as-code and CI/CD, and mentor junior engineers to deliver reliable, AI-powered features.

As a Staff Engineer for Revenue, you'll shape technical vision and architecture for billing and pricing systems, ensuring correctness while enhancing cross-team collaboration.