Top Senior Backend Engineer Jobs in Denver & Boulder, CO

Build and enforce workload safety standards across Affirm’s Amazon EKS fleet. Responsibilities include Kubernetes resource management, workload isolation, disruption handling, cluster capacity analysis, policy automation, production debugging, incident response, fleet-wide rollouts, technical leadership, mentoring, and measuring infrastructure impacts on availability, latency, risk, and cost.

Own and deliver highly available, low-latency backend identity systems supporting consumer onboarding, authentication, and verification. Lead quarterly team goals, guide engineers through ambiguous problems, collaborate with product and design partners, monitor system reliability, improve engineering standards, support on-call operations, and mentor team members. The role requires designing and launching distributed systems at scale using Python or Kotlin, AWS, MySQL, and Kubernetes.

Build and ship backend features end-to-end using Ruby on Rails and SQL. Lead complex technical projects, solve architecture challenges, establish standards, conduct meaningful code reviews, resolve high-risk bugs, document systems, collaborate across engineering teams, and mentor junior engineers.

Leads architecture and hands-on development of scalable backend systems and APIs supporting real-time applications. Owns the engineering lifecycle, writes high-performance code, establishes testing and reliability practices, resolves production issues, guides technical roadmaps, collaborates cross-functionally, and mentors engineers. The role requires expertise in object-oriented backend development, distributed cloud systems, automated testing, system monitoring, and technical leadership.

Lead technical vision and strategy for Affirm’s Cards backend engineering organization. Architect scalable and reliable platforms, guide cross-team initiatives, champion AI adoption and engineering excellence, influence technical roadmaps, and mentor engineers through Staff level. The role requires strong architectural expertise, organizational leadership, project management, communication, and cross-functional collaboration.

Own and deliver backend lakehouse infrastructure goals, lead engineers through complex problems, and build highly available distributed data systems. Collaborate with product, design, analytics, and engineering stakeholders; define scalable technical solutions; improve code quality and engineering standards; monitor operational health; support on-call responsibilities; and mentor team members.

Design and scale foundational APIs and backend services for LogicGate’s multi-tenant GRC platform. Build distributed systems using Java/Kotlin, Spring Boot, AWS, databases, caching, and messaging technologies. Improve reliability, observability, performance, testing, and CI/CD practices. Lead technical design reviews, collaborate cross-functionally, mentor engineers, and use AI coding tools to improve development efficiency.

Build and lead development of high-availability backend services for Affirm’s card loan platform. Design scalable APIs, data models, microservices, and event-driven systems supporting real-time loan attribution, approvals, origination, and refunds. Drive technical strategy, troubleshoot complex performance issues, collaborate with cross-functional teams, and mentor engineers while ensuring long-term system robustness and scalability.

Architect, build, and operate large-scale relational and distributed SQL database infrastructure. Responsibilities include database control-plane automation, provisioning, failover, backups, upgrades, zero-downtime migrations, Kubernetes networking, connection proxy optimization, reliability monitoring, capacity planning, and operational support. The role also leads technical delivery, mentors engineers, establishes quality standards, collaborates cross-functionally, and contributes to team roadmap and on-call operations.

Build and operate production-grade Python backend services, APIs, distributed systems, data pipelines, and agentic workflows for an AI observability platform. Own ambiguous projects from prototyping through architecture, testing, deployment, and ongoing operation. Collaborate with product, machine learning, and infrastructure teams, while contributing React front ends when needed. The role requires strong backend depth, distributed-systems expertise, cloud experience, and end-to-end product ownership.

Own and evolve a high-traffic catalog API for satellite imagery. Design backend services and data pipelines in Python, optimize PostgreSQL performance over large geospatial datasets, operate cloud infrastructure, and deliver reliable deployments with automated testing. The role offers significant architectural ownership on a small, autonomous team and involves geospatial standards, scalable services, and production modernization.

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.

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.

Design, develop, test, and maintain backend services and APIs for secure fintech and crypto products. Collaborate with engineering and product teams on architecture, code reviews, system design, and deployment using Azure. Optimize backend performance and scalability, resolve defects, follow DevOps and CI/CD practices, and build reliable systems supporting payments, transfers, and other financial activity.

Build and operate reliable backend systems for complex government and enterprise data integrations. Responsibilities include designing bidirectional integrations, asynchronous workflows, retries, idempotency, observability, operational automation, debugging production systems, and creating reusable reliability patterns. The role involves TypeScript and Node.js development, database work, partner collaboration, mentoring, and improving support efficiency in a fully remote environment.

Build scalable backend services and infrastructure for mobile and web products. Design secure RESTful APIs, architect high-performance systems, apply engineering best practices, estimate and track Agile tasks, mentor teammates, collaborate with clients and engineers, and take ownership of technical solutions.

Design, build, test, and maintain high-volume, low-latency backend applications. Lead software development across the full lifecycle, analyze requirements, create technical designs and documentation, resolve technical issues, propose infrastructure improvements, and support architectural reviews. Collaborate with cross-functional teams to align technical solutions with business objectives while applying modern development practices and cloud technologies.

Design, build, operate, and maintain highly available distributed telemetry systems for Grafana Cloud and open-source projects. Deliver features end to end, improve reliability and performance, review code and designs, manage releases, participate in follow-the-sun on-call rotations, and collaborate remotely with teammates and customers. Work primarily with Go across Kubernetes-based cloud infrastructure and observability systems such as Mimir, Loki, Tempo, and Pyroscope.

Build and operate scalable database systems for an AI-native, multi-tenant SaaS data platform. Responsibilities include ingestion, query planning, distributed query execution, storage and data formats, retrieval APIs, tenant isolation, usage tracking, observability, and service reliability. The role requires architectural ownership, pragmatic experimentation, cross-functional collaboration, and production delivery across cloud-native environments.

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.

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 develop scalable backend systems using Kotlin, Micronaut, and Spring. Build RESTful APIs, optimize PostgreSQL and Elasticsearch databases, implement RabbitMQ-based asynchronous processing, integrate AI tools, and create automated tests. Deploy and monitor services on GCP using Docker, Kubernetes, and Terraform. Collaborate cross-functionally, participate in code reviews, troubleshoot performance issues, and deliver reliable backend products.

Leads the design, development, and maintenance of complex backend software systems. Owns significant features end to end, makes architectural decisions, improves scalability and performance, ensures code quality, mentors engineers, and collaborates with cross-functional teams. Builds production-ready C# and .NET APIs within microservices and containerized environments, using cloud databases and services. Participates in code reviews, testing, debugging, and continuous improvement.

Build Nitra Business Banking backend infrastructure, including account opening, payments, ledgers, transaction processing, reconciliation, APIs, and financial integrations. Design reliable money movement across ACH, wires, RTP, and FedNow while ensuring auditability and financial correctness. Partner with sponsor banks and processors, make architecture decisions, document systems, identify risks, and mentor engineers. The role also integrates banking capabilities with cards, BillPay, expense management, accounting, and healthcare payment products.

Design, build, and operate backend services supporting external penetration testing, including Python APIs, workflow orchestration, ETL pipelines, AWS data lakes, GraphQL and graph APIs, Kubernetes infrastructure, and observability systems. Own service performance, scalability, uptime, deployment, and production operations while collaborating with product, design, and frontend teams. Contribute to architecture, technical documentation, platform stability, and user-facing launches.