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

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.

Build and ship full-stack web and mobile experiences across Affirm’s consumer products. Break down projects, collaborate with product, design, and analytics teams, develop scalable APIs, write well-tested code, monitor service health, participate in on-call support, review code, and contribute to engineering growth and interviewing.

Lead design and delivery of full-stack basketball scoring, statistics, and postgame features. Build scalable backend services and APIs with TypeScript and Node.js, develop React web experiences, support iOS and Android products, and make architectural decisions. Collaborate across product, design, and engineering teams, ensure code quality and system reliability, mentor peers, and contribute to technical standards and tools.

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.

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.

Build and maintain scalable full-stack systems, backend services, distributed systems, and APIs powering LaunchDarkly’s AgentControl product. Develop primarily with Go, Python, and TypeScript while working with AWS, CockroachDB, Datadog, DeepEval, and FastAPI. Responsibilities include architecture, performance optimization, reliability, production ownership, on-call support, design collaboration, mentoring, and developing AI and GenAI workflows.

Develop and maintain a large-scale production web application across UI and API tiers. Responsibilities include implementing frontend enhancements, fixing bugs, improving accessibility and performance, developing Python-based APIs, supporting third-party integrations and batch processing, enhancing search and administrative features, migrating legacy data, and ensuring application scalability, security, and reliability across multiple releases.

Develop firmware, backend systems, and tooling for cellular IoT devices. Responsibilities include C development for STM32 microcontrollers, embedded AI integration, cellular communication, low-power optimization, device debugging and validation, and backend development with Python and Ruby on Rails. The role collaborates with hardware, electronics, and manufacturing teams and requires independently leading complex development initiatives.

Develop and optimize React and Next.js applications, collaborate with backend engineers on end-to-end features, lead projects, write technical designs, manage Jira tasks, run A/B tests, maintain observability, and support production stability. The role requires strong frontend performance, UI/UX, CI/CD, monitoring, and cross-functional collaboration skills in a fully remote environment.

Designs, trains, evaluates, and operationalizes intelligent document-processing solutions using OCR, machine learning, LLMs, Python, and cloud data pipelines. Builds extraction, validation, reconciliation, exception-handling, and human-review workflows for sensitive information. Develops secure, auditable, configuration-driven systems with API integrations, monitoring, testing, CI/CD, and infrastructure as code. Partners with business experts to define document fields, quality thresholds, validation rules, and acceptance criteria.

Develop and maintain enterprise full-stack applications using Java Spring Boot, REST APIs, modern front-end frameworks, Oracle Exadata, and OpenShift/Kubernetes. Responsibilities include legacy code analysis, full-lifecycle development and testing, SQL and PL/SQL optimization, microservices deployment, CI/CD, code reviews, architecture discussions, monitoring, and Agile collaboration. The role requires an active transferable IRS MBI moderate-risk public trust investigation, U.S. citizenship, and substantial full-stack and cloud-native development experience.

Develop and enhance Grafana data source plugins integrating databases and third-party services. Support plugin reliability and operations in Grafana Cloud, integrate data sources with agentic workflows, improve processes, assist with customer escalations, and collaborate across the Grafana Division. The role requires full-stack software development using Golang and TypeScript, Kubernetes and microservices experience, robust coding practices, and participation in on-call and SRE operations.

Build and operate full-stack features across database, API, and front-end layers using Ruby on Rails. Own complex problems end to end, modernize legacy systems, design durable APIs, improve reliability and developer productivity, and participate in production support. Collaborate with product and engineering teams, document technical decisions, mentor peers, and contribute to architecture, code reviews, and on-call operations. The role also involves using modern developer tooling and working on scalable fleet and service-management software.

Design, develop, test, and maintain scalable full-stack applications supporting Scripture access. Guide software and infrastructure decisions, diagnose technical issues, improve application performance and security, participate in Agile delivery, mentor engineers, conduct constructive code reviews, document systems, and lead AI-enabled software engineering improvements.

The Senior Full Stack Engineer will modernize legacy systems to microservices, maintain .NET applications, optimize SQL databases, and develop frontend interfaces.

Maintain and modernize a stable .NET/SQL Server platform while leading migration from monoliths to cloud-native microservices. Design APIs and event-driven patterns, containerize deployments, optimize backend .NET apps and SQL performance, and build responsive frontends integrated with microservices. Collaborate across cross-functional teams to ensure scalable, highly available systems.

The Senior Full Stack Engineer will maintain legacy .NET systems while leading modernization efforts towards a cloud-native microservices architecture, managing both backend and frontend development tasks.

Design, develop, test, deploy, and support enterprise full-stack applications using React, Java/Spring Boot, and Python. Build secure APIs, microservices, integrations, chatbot interfaces, and cloud-native solutions. Work with Azure or AWS, Docker, Kubernetes, CI/CD pipelines, databases, messaging systems, and enterprise security practices. Collaborate in agile teams, participate in architecture discussions, refine requirements, conduct code reviews, and maintain quality through automated testing. Experience integrating AI or generative AI solutions is preferred.

Build and scale backend-focused systems supporting truckload freight operations, including high-volume carrier quotes, automated transactions, distributed services, and APIs. Design scalable data models and architectures, contribute across the React and TypeScript stack, make key technical decisions, mentor engineers, and collaborate with product leadership. The role also involves developing AI-powered logistics tools and maintaining reliable, secure infrastructure on Kubernetes and GCP.

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.

Join a small engineering team as a hands-on full stack developer. Accelerate frontend delivery, then take on backend services, infrastructure, and core capabilities. Own features from design through release and operational stability, collaborate with customer-facing engineers and founders, and promote effective AI-assisted development practices. The role requires strong backend-oriented full stack skills, product-launch experience, system design judgment, self-direction, and periodic travel to a California office.

Lead design, development, testing, and deployment of cloud-native full‑stack applications and microservices. Provide technical leadership, mentor engineers, implement CI/CD and automated tests, and drive modernization using GCP or similar cloud platforms, containers, and enterprise security best practices.

Own backend services and frontend experiences across signup, onboarding, verification, activation, checkout, and customer lifecycle management. Build event-driven systems, integrate identity and risk providers, handle sensitive financial data, run experiments, and analyze funnels using SQL and Snowflake. The role also involves evaluating AI-generated code, analysis, and customer messaging while collaborating with Product, Data, and Risk in an ambiguous, high-ownership environment.

Design, implement, and maintain scalable serverless backend services and responsive Next.js front-end components. Build data scrapers and integrations, improve CI/CD and IaC, mentor junior engineers, and collaborate with product and clients to solve complex compliance problems.