Top Senior Full-Stack Engineer Jobs in Denver & Boulder, CO

Build backend-focused Java/Kotlin APIs and data-driven product features, while contributing to React dashboards and workflows. Design scalable systems, participate in architecture and code reviews, troubleshoot production issues using observability tools, and collaborate with data, reporting, design, and product teams to launch emerging products.

Develop fullstack web applications, enhance platform performance, collaborate on high-impact opportunities, and ensure stable, scalable solutions. Engage in rapid iterations and be a committed team player.

Develop and deploy customer-focused web, mobile, and backend applications across the full software stack. Design major features, contribute to architecture decisions, conduct code reviews, and ensure secure, high-quality implementations. Collaborate with stakeholders and cross-functional teams using Agile and SDLC practices. Manage version control, CI/CD, environments, and releases; maintain automated test coverage and perform root-cause analysis. Build and optimize relational data solutions using SQL Server, including complex queries, stored procedures, and performance tuning.

Build and own CRM features and workflow automations supporting sales, marketing, onboarding, and support. Develop full-stack functionality using Next.js, FastAPI, Inngest, and related technologies; partner with teams to automate workflows; create agentic solutions for enrichment and task automation; and manage features from planning through monitoring and refinement. The role requires strong web development expertise, product sense, autonomy, communication, and experience with modern JavaScript or TypeScript frameworks and orchestration tools.

Leads technical vision and strategy for Affirm’s Marketplace, Search, Ads Platform, and consumer experiences. Designs scalable full-stack platforms, guides architecture and technical excellence, coordinates initiatives across engineering teams, mentors engineers, and drives reliable delivery of customer-focused products across iOS, Android, and Web.

Build and maintain full-stack web features across database models, APIs, services, and user interfaces. Own product workflows from requirements and design through deployment, write production-ready code, collaborate with product and design, improve system reliability, and lead continuous releases. The role requires strong React, TypeScript, and Node.js experience, autonomy, clear communication, and a bias toward execution in a startup environment.

Lead end-to-end development of customer-facing product experiences and backend systems across frontend and backend layers. Design scalable services, APIs, and data flows; improve accessibility, performance, reliability, security, observability, and maintainability. Partner with Product, Design, Data, and engineering leaders to deliver complex initiatives, influence architecture, support incident response, mentor engineers, and connect technical decisions to customer and business outcomes.

Lead full-stack software development across frontend and backend systems, delivering user-facing healthcare features from concept through iteration. Design APIs and application architecture, write technical specifications, improve testing and CI practices, collaborate with product, AI/ML, clinical, and UX teams, and guide cross-team technical decisions. The role involves React, Python, cloud infrastructure, databases, asynchronous workflows, and healthcare data technologies.

Provides technical leadership for AI Trust and Governance engineering, designing scalable cloud-native services and distributed systems. Responsibilities include architecture, systems programming, concurrency, testing, debugging, deployment, release management, cross-team collaboration, and mentoring engineers. The role requires strong Java or C skills, expertise in distributed systems and consensus algorithms, and ownership of enterprise platform features from design through delivery.

Design, build, and maintain production-grade .NET web applications and APIs on Azure. Own full-stack delivery from data models and SQL to front-end components, CI/CD, testing, and architecture. Collaborate with product and delivery teams, participate in code reviews, and ensure secure, observable, well-tested services.

Lead the architecture and delivery of cloud-native, full-stack GEOINT systems and microservices. Develop secure distributed applications, govern AWS and Kubernetes deployments, build DevSecOps pipelines, integrate data and analytics platforms, guide modernization and technical roadmaps, mentor engineers, and partner with mission users. The role requires active TS/SCI clearance and supports classified environments.

Lead the architecture, modernization, and implementation of secure, cloud-native GEOINT applications and microservices. Develop scalable backend services, govern AWS and Kubernetes deployments, implement DevSecOps pipelines, integrate data and search platforms, and guide technical roadmaps. Partner with mission users and engineering teams, mentor developers, conduct code reviews, and evaluate AI technologies. The role requires experience with distributed systems, APIs, databases, cloud infrastructure, classified environments, and an active TS/SCI clearance.

Lead complex software projects and mentor engineers while building scalable full-stack products for Vanta’s expansion team. Develop purchasing, checkout, upgrade, renewal, billing, and trial experiences that support self-serve growth and revenue automation. Set technical direction, own product functionality and infrastructure, collaborate across teams, and contribute to engineering culture. The role uses TypeScript, React, and Node.js and involves greenfield development in a rapidly scaling startup environment.

Build and maintain Grafana Cloud integrations and observability features across frontend (TypeScript/React), backend (Golang), and monitoring mixins (Jsonnet). Ship end-to-end features, own projects to production, contribute upstream to OpenTelemetry/Prometheus, run on-call for owned services, and communicate designs and demos across teams.

Lead end-to-end design, development, and delivery of full‑stack features; drive architecture and code reviews; coordinate engineering work, write design docs and tests, and participate in Agile ceremonies. Must have blockchain/crypto experience.

Build end-to-end features in a JS/TS stack, designing scalable backend services and responsive real-time frontends. Improve observability, performance, and reliability, collaborate with product/design, and own full-stack implementation from APIs and data models to UI.

Lead architecture and implementation of scalable web applications using NestJS and Next.js. Build and optimize PostgreSQL schemas and queries, implement responsive UIs with Tailwind CSS, integrate LangChain-driven AI features, manage authentication with Clerk, and create end-to-end tests and automation with Puppeteer to ensure launch readiness and reliable user experiences.

Design, build, and own scalable multi-tenant SaaS applications across frontend, backend, and data layers. Improve system architecture, performance, reliability, and testing practices. Integrate AI-assisted tools, mentor engineers, conduct code reviews, and collaborate with Product and Design to deliver intuitive, production-grade software.

Build and optimize BizzyCar’s full-stack platform using Ruby on Rails APIs and Angular. Own features end to end, diagnose issues across UI, APIs, and data, guide architecture, mentor engineers, improve testing standards, and support multiple product domains including recalls, AI, and service systems.

Build and maintain full-stack applications for a maritime data management and AI platform. Responsibilities include developing frontend components, real-time WebGPU data feeds, PostgreSQL and Apache Iceberg data models, MQTT and Redpanda pipelines, Dagster batch workflows, machine learning integrations, and CI/CD tooling. The role supports mission-critical products used with U.S. Navy sonar and sonobuoy data.

Build and operate scalable, accessible, high-performance web experiences for Calendly’s marketing website and Help Center. Own projects from technical design through deployment and iteration, develop frontend architecture and CMS integrations, improve SEO, AEO, accessibility, Core Web Vitals, and reliability, and collaborate with Marketing, Content, SEO, Design, Product, and Engineering. Provide technical leadership through testing, code reviews, documentation, mentorship, and architectural improvements.

Own and evolve scalable distributed systems, REST APIs, backend services, and core product areas. Design solutions, improve resilience, reduce technical debt, and drive modularization. Use AI-first and agentic development practices, evaluate emerging AI tools, and help integrate AI across engineering workflows. Collaborate asynchronously with product, data, and go-to-market teams while improving engineering tools, processes, and system reliability.

Design, build, and optimize scalable cloud and web software with focus on infrastructure, performance, and hardware integration for IoT devices. Collaborate with hardware teams to ensure connectivity and high availability, implement new features, and improve system efficiency.

Build full-stack Real User Monitoring features across frontend applications, backend services, APIs, and analytical storage systems. Design high-throughput telemetry ingestion, storage, querying, data models, and indexing strategies. Develop data-heavy user interfaces, optimize performance and costs, collaborate with SDK and cross-functional teams, and own projects from design through deployment, monitoring, testing, and iteration.

Build and ship end-to-end product features across an author analytics dashboard, marketing site, free tools, billing, email, and AI-assisted functionality. Design data models and APIs, integrate third-party services, develop production LLM features, and maintain testing, monitoring, performance, and observability. The role includes code review, technical documentation, independent product decisions, and close collaboration with the founder in a remote-first environment.