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

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.

Build and ship full-stack features for customer-facing Console and Playground, plus internal tools. Design and maintain APIs and backend services, implement accessible performant frontends, translate product requirements into incremental work, and improve code quality through reviews and design discussions.

Develop and deliver production-ready web experiences for marketing using React, Gatsby, and Tailwind. Build API integrations, maintain a lightweight codebase and design-system components, ensure accessibility, performance, SEO, and multi-region support, participate in code reviews, and help shape tooling and best practices across the team.

Owner of end-to-end ecommerce features: design, implement, and maintain scalable backend services and performant React/Next.js frontends. Integrate payment gateways and procurement systems (PunchOut), mentor engineers, uphold code quality, and improve platform stability across Node.js, MySQL, and MongoDB.

Build and own complex frontend features using Vue 3 and TypeScript while developing the Python services and APIs that power them. Improve performance, accessibility, testing, CI/CD, and observability; collaborate with product and design; mentor engineers and apply AI-assisted development tools responsibly to accelerate productivity and maintain quality and security.

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.

The Senior Full-Stack Engineer will manage client relationships, design integration solutions, and ensure seamless delivery and optimization of technical workflows, while leveraging AI for efficiency.

Develop, maintain and evolve a high-scale US sports trading platform. Build React/TypeScript frontends, backend microservices, optimize SQL and performance, implement CI/CD and automated testing, mentor junior engineers, and collaborate with stakeholders and architecture teams to ensure resilience and integration.

Join the Entefy team as a Senior Full Stack Engineer to build a scalable full stack application enhancing digital interaction for global clients.

Lead full‑stack design and delivery of customer-facing web experiences (Browse, Navigate, Preview). Own architecture, APIs, data models, rollouts, observability, on‑call readiness, and cross-team alignment, using approved AI-assisted workflows while ensuring technical quality and reliability.

The Senior Full Stack Developer will build end-to-end solutions, collaborate in a remote environment, and write technical documentation. The role requires expertise in Ruby on Rails and various programming paradigms.

Lead technical direction and delivery for the Acquisition & Onboarding full‑stack team. Build and maintain mobile (React Native/native) and web experiences, backend services at scale, and operational tooling. Drive architecture, mentor engineers, ensure reliability/monitoring/on‑call readiness, collaborate with product and design, and improve dev processes, testing, and release practices to impact conversion and retention.

The Senior Full Stack Engineer will design and implement APIs with NodeJS, develop UIs with React, manage data pipelines, and deploy projects on AWS.

Owner of Vannevar's authentication and authorization platform: build tenant-isolated auth systems, self-service user/group/permission admin UI, tooling to visualize and validate access, feature-flag and platform management interfaces, and shared authorization capabilities across products.

Senior fullstack engineer to build and scale Brigit's consumer finance platform. Own end-to-end features across frontend (React/React Native/TypeScript) and backend (Java/REST/SQL), optimize database and APIs for high scale, integrate 3rd-party services, implement risk and transaction algorithms, improve CI/CD, testing, monitoring, and internal tooling to support millions of users.

Build end-to-end data and analytics features: ingest and model data, build transformations and pipelines, create client-facing dashboards and interfaces, and develop LLM-powered workflows to accelerate analysis and app development. Partner with stakeholders, perform exploratory analyses, and ensure data quality, observability, and maintainability while influencing data engineering strategy.

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.

Hands-on senior full stack engineer to design, code, review, and ship web front ends and backend APIs. Lead technical execution for a small team, define architecture and API contracts, integrate AI/LLM features (tool calling, prompt/control flow), support secure enterprise integrations, and mentor engineers through code review and pairing.

Lead full-stack engineering across client engagements: architect, build, deploy, and maintain web applications, APIs, CMS implementations, and CI/CD workflows. Own technical client relationships, enforce best practices, evaluate AI-enabled development, and support long-term maintenance while balancing accessibility, security, performance, and project constraints.

Build and productionize LLM-backed agents and workflows: create eval harnesses, observability, provenance and human-review surfaces, extend agent capabilities (web/CMS, OAuth), implement pipeline orchestration, and ship scoring/ranking models and reusable modules to scale across clients.

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.

Build and ship full-stack features for North, develop autonomous agents that access sensitive enterprise data, productionize state-of-the-art models, write minimal, secure low-resource code, and collaborate with researchers to deploy performant RAG/agentic applications while prioritizing security and user experience.

As a Senior Full-Stack Engineer, lead development of secure AI-driven SaaS applications, focusing on backend architecture, frontend design, and AI integrations. Collaborate with teams to operationalize models and enhance application functionality through cutting-edge AI solutions.

The Senior Full-Stack Engineer will lead SaaS application development, focusing on backend algorithms, AI integrations, security, and operationalization of models while collaborating with various tech teams.

Design, build, and own scalable, secure full-stack applications. Collaborate with engineers, designers, and managers to gather requirements, estimate work, maintain documentation, and deliver high-quality client-facing software using Agile practices.