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.

Senior full-stack engineer responsible for owning mission-critical software from requirements through deployment and sustainment. The role involves working directly with government users and technical stakeholders, architecting and building products across the stack, integrating with government IT systems, and ensuring security and compliance within DoD environments. The engineer will make product and architectural decisions, support technical proposal artifacts, and travel up to 50% to engage with mission owners in the field.

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 debug production-grade full-stack applications across front-end and back-end systems. Build features, APIs, databases, and data models; troubleshoot end-to-end issues; analyze unfamiliar codebases; translate implementations across programming languages; and review AI-generated and developer-written code for correctness, security, scalability, performance, and maintainability.

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.

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.

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.

Develop and enhance full-stack web applications for CDMRP, including portal integrations, single sign-on, microservices, responsive front-end and back-end features, REST APIs, testing, performance optimization, and legacy modernization. Collaborate with portal, systems administration, and security teams; apply UX practices; document architectures and services; and ensure compliance with DoD security procedures and STIG guidelines.

Develop and deploy responsive full-stack web applications from design through production. Translate product requirements into high-quality software, maintain pixel-perfect design standards, collaborate with product, design, and QA, and help guide technology strategy. The role acts as a technical lead on product initiatives and reports to the CTO, with a focus on AI-native development and secure fintech workflows.

Leads the design, development, and implementation of full-stack applications using C#, .NET, Angular, Azure, and SQL Server. Collaborates with cross-functional teams, ensures application security, performance, and scalability, applies Git-based version control practices, mentors developers, and stays current with emerging technologies.

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.

Develop and operate authentication, authorization, and identity-provider services for APIs, customer products, and internal tools. Build Go backend services, gRPC/REST APIs, shared libraries, and React/TypeScript interfaces, with occasional Java work. Own services end to end, including data modeling, deployments, monitoring, troubleshooting, integrations, testing, incident response, and on-call support.

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.

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.