Top Backend Engineer Jobs in Denver & Boulder, CO

Develop, maintain, and optimize mission-critical backend APIs and scalable cloud services for web and mobile clients. Implement secure, high-performance systems, automated tests, observability, and technical documentation. Mentor peers, follow best practices, and support a proof-of-concept launch and fundraising activities as a volunteer contributor.

Develop, scale, and maintain core backend APIs within a TypeScript/NestJS monolith for supply chain modules (OMS, WMS, MES). Implement secure payment and logistics integrations, caching with Redis, async/event-driven workflows, and observability (OpenTelemetry, Prometheus, Loki). Support AI agent orchestration and ensure transactional integrity using PostgreSQL.

Build reusable backend platforms and developer-facing tooling for performance testing, analysis, reporting, and AI-assisted engineering workflows. Enable service teams to independently incorporate performance testing into development and CI workflows through self-service capabilities, documentation, templates, diagnostics, and guidance. Partner with engineering teams, influence adoption, generalize solutions, and provide expertise on complex performance challenges.

Design and implement backend services, modernize legacy systems into microservices, ensure strong testing and production observability, and collaborate with Product and Engineering teams. The role requires independent project ownership, strong system design, AI-assisted development using tools such as Claude or Cursor, effective communication with nontechnical stakeholders, and adaptability in an ambiguous, fast-changing environment.

Senior backend engineer responsible for designing and implementing new features, scaling and optimizing the platform, improving Postgres and Elasticsearch performance, fine-tuning LLMs, and making architectural decisions. Collaborate with engineering team, take ownership of features, write performant, maintainable code, and help shape product and infrastructure for data-intensive applications (NLP, search, indexing).

Leads cross-team backend initiatives and technical architecture for GitLab’s Core DevOps platform. Responsibilities include modernizing a monolith, establishing service, API, data, security, testing, and observability standards, guiding Go and Kubernetes practices, supporting Rust adoption, participating in incident response, mentoring engineers, reducing technical debt, and advancing AI-assisted engineering workflows.

Leads the design, development, and maintenance of complex backend software systems. Owns significant features end to end, builds scalable APIs and services, ensures code quality and performance, contributes to architecture and technical direction, mentors engineers, and collaborates with cross-functional teams. The role requires extensive C# and .NET experience, insurance industry expertise, microservices, cloud databases, automated testing, and containerized environments.

Design, develop, and maintain scalable, high-performance backend and middleware services on the JVM using Java and Spring/Spring Cloud. Build and enhance microservices, work with AWS and Docker, implement SQL/noSQL solutions (MySQL, Elasticsearch), use Git-based source control and JIRA, collaborate across engineering, design, and QA, and mentor teammates while following best practices and Agile methodologies.

Design and scale Cohere’s Model Vault backend and inference platform. Lead architecture for authentication, deployments, billing, metering, customer lifecycle, and cloud control-plane services. Build reliable distributed systems with strong guarantees for security, privacy, consistency, isolation, observability, and failure recovery. Drive technically complex initiatives from threat modeling and architecture through implementation, production rollout, operations, and iteration at enterprise scale.

Build, maintain, and scale e-commerce backend services using Python and Django. Develop REST APIs and features for catalogs, inventory, carts, checkout, orders, payments, and accounts. Integrate third-party services, optimize databases and performance, implement security controls, write tested code, resolve production issues, and collaborate on architecture, planning, reviews, deployment, and CI/CD.

Design and implement scalable backend services for MoneyGram’s core transaction and API platforms. Responsibilities include architecture, microservices, APIs, event-driven systems, integrations, cloud development, CI/CD automation, testing, deployment, operational excellence, and engineering standards. The role collaborates with product, engineering, and QA teams, mentors junior engineers, leads complex technical solutions, and influences technical direction in an agile environment.

The Senior Software Engineer will design and develop backend systems and APIs, mentor other engineers, and resolve complex integration challenges in healthcare technology.

Design, implement, and maintain scalable, secure, high-performance backend systems and public-facing APIs. Collaborate with Product and Data Science teams, lead initiatives improving efficiency and system performance, and support customer satisfaction. Work may involve distributed systems, pricing engines, identity management, authentication, authorization, API versioning, deprecation, and rate limiting.

Develop Java and Spring Boot microservices, REST APIs, and serverless AWS Lambda functions. Integrate Vue.js frontends, write automated JUnit and Mockito tests, manage CI/CD pipelines, deploy containerized applications to AWS EKS, and collaborate on scalable cloud-native systems. Preferred experience includes PostgreSQL, DynamoDB, Docker, and EKS monitoring and logging tools.

Own technical direction and complex projects for Tempo, Grafana’s distributed tracing backend. Build and optimize ingestion, storage, query, metrics, and API components; improve performance, scalability, reliability, and operational excellence. Collaborate across product and engineering teams, write design documentation, participate in on-call and incident response, mentor engineers, and contribute to the open-source Tempo project.

Build and operate core platform systems for users, workspaces, permissions, APIs, authentication, and resource management. Deliver full-stack features with a backend focus, including admin and settings interfaces. Scope work within large existing systems, plan migrations, manage safe rollouts, debug production issues, and collaborate across product and engineering teams. Candidates need strong Python and backend development expertise, software and system design knowledge, testing and security fundamentals, and the ability to navigate ambiguity.

Build and maintain payments infrastructure, including usage tracking, pricing, billing, payment providers, and stream-processing services. Collaborate with Finance, Tax, Growth, Sales, and engineering teams to support compliance, reporting, experiments, and customer payments. Plan migrations, debug complex production billing issues, and safely evolve live systems handling money. Requires Python expertise, backend development experience, software and system design knowledge, testing and security fundamentals, and strong problem-solving ability.

Owner of core clinical backend systems: design and build TypeScript/Nest.js APIs, model clinical domains in PostgreSQL/Prisma, implement onboarding/migration flows, ensure CI/CD, monitoring, HIPAA/SOC2 readiness, collaborate with clinical stakeholders, and build monitoring/reporting with Sentry/Datadog on AWS.

Design, build, test, and support EPIC integration solutions across the full interface lifecycle. Gather requirements, resolve integration issues, develop standards and documentation, and provide production support within a remote, volunteer, part-time setup.

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.

Owns application and API services for a multi-tenant, multi-cloud AI platform serving enterprise finance teams. Responsibilities include designing versioned APIs, building review and approval workflows, enforcing authentication, authorization, and tenant isolation, creating auditable systems, supporting customer-hosted deployments, and managing service performance, reliability, observability, and cost. The role also establishes backend patterns, reviews designs, mentors engineers, and partners with data, AI, and product teams.

Owns core backend computation services that produce correct, reproducible, traceable, and auditable financial results. Designs configuration-driven architectures, data-intensive services, and set-based warehouse computations. Requires strong Python, SQL, data modeling, system design, reliability, isolation, and testing expertise. Provides technical leadership through design reviews, engineering standards, and mentorship while partnering with data, AI, and product teams.

Designs, builds, and scales backend services and integrations for payments, billing, identity, and partner connectivity. Sets technical vision and architecture for distributed systems, leads cross-team delivery, manages production rollouts, builds fault-tolerant services and data pipelines, and mentors engineers. The role partners with product, design, and engineering teams to deliver frequent, reliable improvements for Flex’s rent payment platform.

Design, build, and scale backend services and integrations for payment, billing, identity, and partner systems. Own API scoping, design, implementation, deployment, and production operations with minimal oversight. Build fault-tolerant systems, data pipelines, and scalable architectures while collaborating with product, design, engineering, and external partners. Contribute to reliability monitoring, observability, automation, technical standards, and mentoring in a distributed team.

Design and build backend services and distributed systems for a customer-facing no-code product. Improve query performance across large data warehouses, develop analytics and experimentation capabilities, explore real-time computation and data syncing, and apply generative AI to user workflows. The role also involves writing product specifications, collaborating directly with users, making long-term architecture decisions, and ensuring services remain robust, maintainable, and scalable.