Lead Developer - Middleware Software

Frontier Airlines, Inc.; Denver (CO); Remote; USD 123,000 - 164,000; Full time

Benefits offered by this job

Travel privileges

Buddy passes

Employee discounts

Hybrid schedule for Denver HQ roles

Job summary

Frontier Airlines, Inc. is seeking a Lead C# Middleware Software Developer with 12+ years of .NET experience to guide backend solutions in a cloud-first environment. You will architect, develop, and lead enterprise-grade microservices and APIs, collaborating with architects and product owners, while mentoring teammates.

The role emphasizes agile delivery, CI/CD, and secure, scalable designs across Website, Mobile App, and Middleware platforms. Remote-friendly with occasional on-site needs.

Qualifications

• Bachelor’s degree or equivalent experience.
• 12+ years in Microsoft stack with C#, .NET Framework/Core.
• Experience as a Solution Architect leading development efforts.
• Design, development, testing, and deployment of software systems.
• Microservice design in an enterprise context.
• Hands-on with Docker and Kubernetes.

Responsibilities

• Develop, test, and maintain enterprise-level microservices APIs on Microsoft technologies.
• Lead design reviews and code reviews within an agile team.
• Provide architecture guidance across full stack and ensure security standards.
• Mentor senior, mid-level, and junior team members.
• Ensure continuous integration/builds are in working order.
• Collaborate with QA to triage and fix bugs.
• Document technical designs and code changes.

Skills

C#

.NET Core

Microservice design

Azure/AWS

Docker

Kubernetes

REST APIs

JavaScript/TypeScript

API Management

CI/CD

Education

Bachelor's degree

Tools

Microsoft DevOps GIT

Azure/AWS

Terraform / CloudFormation

Job description

Working at Frontier Airlines

At Frontier, our mission is to Make Every Flight Count. That mission guides how we support our customers, our people, and the operation every day.

Working at Frontier Airlines

At Frontier, our mission is to Make Every Flight Count. That mission guides how we support our customers, our people, and the operation every day. As a Frontier employee, your work connects to more than a single role. Whether you’re supporting flights, helping customers, maintaining aircraft, leading teams or working behind the scenes, you help create a travel experience that is safe, reliable and built around value. Our work is guided by our core values: customer first, safety always, operational excellence and one team. These values shape how we make decisions, support each other and deliver for the people who count on us.

Support for work, life and travel

Frontier offers benefits, programs and travel privileges designed to support eligible employees at work and beyond. Availability may vary by role, employment status, eligibility, location, schedule, applicable policies and current plan details.

Depending on role and eligibility, available benefits and programs may include:

• Medical, dental and vision coverage
• 401(k) retirement savings options
• Paid holidays, vacation time and sick time
• Travel privileges on Frontier Airlines and participating partner airlines, based on current program rules and availability
• Buddy passes, based on eligibility and program rules
• Travel-related discounts and employee discounts on select products, services and vendors
• A hybrid schedule for eligible headquarters roles based in Denver, Colorado
• Business casual dress options for eligible corporate and support roles
• Employee support programs and resources, including the HOPE League, Frontier Airlines’ nonprofit organization

About Frontier Airlines

Frontier Airlines is a Denver-based airline serving destinations across the United States and select international markets. Our people support every part of the travel journey, from airport operations and flight crews to aircraft maintenance, customer support, corporate teams and more.

We’re focused on delivering meaningful value by making travel more accessible, practical and easy to personalize for our customers. Across the airline, our teams help support a safe, reliable and efficient operation while continuing to strengthen the experience for the people who choose Frontier.

What Will You Be Doing?

The Lead Middleware Software Developer must have extensive working knowledge in software development and of software engineering practices. In addition, must have experience collaborating with architects, project managers, and product owners to help deliver high-quality software features that exceed the expectations of our customers. Also, must be equally capable of working independently in a fast-paced environment. This developer will lead projects and have a large range of control over application design, technology stack decisions, and development.

Frontier Airlines is currently reviewing qualified candidates for a full‑time Lead C# Middleware Software Developer. The ideal candidate is someone with 12+ years of development experience in Microsoft .NET technologies and 6+ years of experience leading and architecting enterprise-level backend solutions. For the right candidate, Frontier Airline’s development environment provides a unique opportunity to be part of a team rebuilding the entire commercial software system (Website, Mobile App, Middleware). It will be designed and implemented in an ultra‑modern cloud‑first architecture where you will take the lead in one or more areas of development and be a key player.

Essential Functions

• Work within an agile team to develop, test, and maintain enterprise-level microservice APIs built on Microsoft technologies (C#, .NET Core, Web API, SQL Server, CosmosDB)
• Participate in bi-weekly sprint planning sessions, helping to provide sub‑tasks and estimates for user stories for the work to be done in the upcoming sprint
• Participate and lead peer reviews of solution designs and code
• Provide expertise and leadership across the full stack of technologies
• Adhere to and set architecture standards, risk management, and security policies
• Develop technical documents to accurately represent application design and code
• Work closely with QA to triage and fix bugs
• Participate in the evolution of best practices, standards, and policies as it relates to software development
• Write code that is simple, maintainable, reusable, and conforms to team coding style and standards
• Accurately maintain code in source control system (Microsoft DevOps GIT), appropriately documenting and commenting check‑in and merge activities
• Test deliverables against a user story’s acceptance criteria including the use of multiple browsers for desktop and mobile environments
• Assist, mentor, lead, and guide senior, mid‑level, and junior team members
• Ensure continuous integration and builds are in working order

Qualifications

• Bachelor’s degree from a four‑year college or university; or equivalent combination of education and experience
• 12+ years of experience within the Microsoft technology stack, including hands‑on experience using C#, .NET framework, and .NET Core
• Experience as a Solution Architect leading development efforts, including technology stack decisions and putting together proof of concepts to be reviewed by other solution architects and the leadership team
• Experience with design, development, testing, and deployment of software systems or applications
• Microservice design and implementation experience in an enterprise‑level application is required
• Hands‑on experience with container technologies like Docker and K8s
• Experience developing and working with web services (REST/SOAP/GraphQL) and knowledge of industry standards such as OpenAPI, OAuth, SSO, etc.
• Experience with JavaScript/TypeScript
• Experience developing database‑driven web applications with Microsoft tools and technologies including ADO.NET, Entity Framework, and micro ORMs
• 5+ years’ experience with cloud technologies Azure/AWS
• Expert knowledge of API Management solutions
• Experience with test‑driven development (TDD), unit testing, and continuous deployment principles in an Agile environment

Cloud‑Native Engineering

• 5+ years of experience designing and deploying cloud‑native solutions within Azure and/or AWS.
• Hands‑on experience with Infrastructure as Code (Terraform, Bicep, CloudFormation).
• Experience with container orchestration platforms such as Kubernetes (AKS/EKS) and cloud‑native application patterns.
• Experience implementing serverless architectures utilizing Azure Functions, AWS Lambda, Event Grid, Service Bus, EventBridge, SQS, SNS, Kafka, or equivalent technologies.
• Experience implementing observability solutions including Azure Monitor, Application Insights, Datadog, Splunk, OpenTelemetry, Grafana, or similar platforms.

Knowledge, Skills And Abilities

• Expert working knowledge of object‑oriented design/programming, n‑tier web applications, XML\JSON, ASP.NET, and relational databases
• Strong object‑oriented design skills
• Knowledge of the Software Development Life Cycle
• Detail‑oriented with a meticulous focus on producing the highest quality results
• Ability to work effectively and lead in a fast‑moving, multi‑project team environment
• Work effectively in an Agile development process
• Clear and effective written and verbal communication as well as strong interpersonal skills
• Excellent problem‑solving skills
• Ability to develop code for testability
• Capable of learning new technologies and platforms quickly and presenting solutions to the leadership team
• Ability to work individually and in a team environment
• Self‑motivated and able to handle responsibilities without consistent oversight
• Knowledge of applicable data privacy and security practices and laws, PCI, and/or SOX a plus
• Strong understanding of distributed systems, event‑driven architectures, and cloud‑native design patterns.
• Knowledge of AI application architecture, prompt engineering, Retrieval Augmented Generation (RAG), vector databases, and enterprise AI integration patterns.
• Ability to evaluate, prototype, and recommend emerging AI technologies and cloud services.
• Experience implementing secure AI solutions that comply with enterprise governance, privacy, PCI, SOX, and security requirements.
• Expert knowledge of API Management, identity management, OAuth2, OpenID Connect, SAML, Zero Trust, and enterprise integration architectures.
• Strong understanding of DevSecOps, CI/CD automation, platform engineering, and cloud security practices.

Equipment Operated

Standard office equipment, including personal computers, Apple computers, various and future tablets, smartphones and wearable technology, copiers, fax machine, printer, phones, and future and upcoming technology that may not yet be publicly available

Work Environment

Remote office environment. This requires the employee to have adequate space and internet access to conduct their job and participate in online video meetings using various video conferencing solutions.

This position may require the occasional visit to Frontier’s headquarters for team meetings and occasional visits to airport locations for on‑site testing.

Physical Effort

Generally, not required.

Supervision Received

General Direction: The incumbent normally receives little instruction on day‑to‑day work and receives general instructions on new assignments.

Salary Range: $123,462 - $163,873.

Please note: this posting will expire on or before 12.31.2026.

Positions Supervised

• None

Workplace Policies

Disclaimer: The above statements are intended only to describe the general nature and level of work required of the referenced position; they are not intended to be an exhaustive list of all responsibilities, duties, and skills required of individuals in this position. Please be advised that duties and expectations of this position may be subject to change.

Frontier Airlines, Inc. is an equal opportunity employer and, as such, is committed to providing equal employment opportunities to all qualified applicants without regard to race, color, religion, sex, national origin, age, marital status, veteran status, sexual orientation, gender identity or expression, disability status, pregnancy, genetic information, citizenship status or any other basis protected by federal, state, or local laws. This policy applies to all terms and conditions of employment, including recruiting, hiring, placement, promotion, termination, layoff, recall, transfer, leaves of absence, compensation and training.

Frontier Airlines is a Zero Tolerance Drug‑Free Workplace. All prospective DOT safety‑sensitive employees are subject to pre‑employment testing for the following drugs and their metabolites: Marijuana, Cocaine, Amphetamines, Opioids and Phencyclidine (PCP). Further, any DOT safety‑sensitive job applicant who is found to have tested positive on any required drug or alcohol test at a former employer will be considered ineligible for employment with Frontier.

Colorado Residents: In any materials you submit, you may redact or remove age‑identifying information such as age, date of birth, or dates of school attendance or graduation. You will not be penalized for redacting or removing this information.