Senior Full Stack Engineer

FacilityOS; Annapolis (MD); Hybrid; USD 120,000 - 170,000; Full time

Benefits offered by this job

Comprehensive health coverage

Hybrid work environment

Opportunity for advancement and growth

Catered events, snacks, drinks

Birthday and life celebrations

Two annual parties

Job summary

FacilityOS, a fast-growing platform for safety, security, and daily operations, seeks a Sr. Full Stack Engineer to ramp quickly and deliver meaningful outcomes.

You will work with legacy systems, apply strong architectural principles, and make technical decisions that improve delivery throughput without compromising quality. The ideal candidate has backend .NET experience, solid Angular/TypeScript skills, and a track record of building cloud-native SaaS/PaaS apps.

Qualifications

• 6+ years of backend .NET Framework / .NET Core development in C#.
• 5+ years of web apps using Angular and TypeScript.
• Strong ability to understand complex legacy systems and integrate points.
• Experience with OO design, patterns, and clean architecture.
• Proven unit testing and quality-focused practices.
• Experience designing RESTful services and cloud-native SaaS/PaaS apps.

Responsibilities

• Design, develop, review, and maintain backend web apps and services on the FacilityOS platform.
• Understand platform architecture, legacy components, and modernization opportunities.
• Collaborate with engineering to align with architecture and delivery goals.
• Contribute to legacy modernization with incremental, low-risk approaches (e.g., Strangler Fig).
• Maintain high code quality via reviews, tests, static analysis, and tooling improvements.
• Engage in peer reviews, provide constructive feedback, and promote scalable solutions.
• Troubleshoot issues across environments (staging/production) focusing on root cause.
• Work with leads, product stakeholders, and PMs to support operations and delivery.
• Research and recommend architectural improvements for FacilityOS.

Skills

Backend .NET / C#

Angular & TypeScript

RESTful APIs

Cloud-native apps (Azure/AWS)

SQL Server / T-SQL

OO Design & Clean Architecture

Unit testing

Event-Driven Architecture

Microservices

Independent collaboration

Job description

About FacilityOS

FacilityOS is a fast-growing company redefining how facilities operate—bringing safety, security, and daily operations into one unified platform used by organizations around the world.

About FacilityOS

FacilityOS is a fast-growing company redefining how facilities operate—bringing safety, security, and daily operations into one unified platform used by organizations around the world.

As we continue to scale globally, we’re building a team of driven, curious people who want to make an impact. You’ll be part of a dynamic, collaborative culture where individuals are trusted to take ownership, solve meaningful problems, and grow in their careers.

Our team comes together in-office twice a week to connect, collaborate, and build momentum.

If you’re looking to do your best work alongside a great team in a high-growth environment, FacilityOS is the place to build your career.

About The Role

We are looking for a highly capable Sr. Full Stack Engineer who can ramp up quickly, collaborate effectively with the existing team, and begin contributing meaningful delivery outcomes within the first few weeks.

This role is well suited for someone who is comfortable navigating legacy systems, applying strong architectural principles, and making thoughtful technical decisions that improve delivery throughput without compromising quality.

The ideal candidate brings strong backend engineering experience, sound judgment, and the ability to work independently while staying closely aligned with team standards and architectural direction.

This role is a hybrid position where you’ll be required to come into our office three (3) times a week.

Duties And Responsibilities

• Design, develop, review, and maintain backend web applications and services across the FacilityOS platform.
• Quickly develop a working understanding of existing platform architecture, legacy components, integration points, and modernization opportunities.
• Collaborate with the engineering team to make sound technical decisions that align with established architectural principles and delivery goals.
• Contribute to legacy modernization efforts using incremental, low-risk approaches such as the Strangler Fig pattern where appropriate.
• Maintain high code-quality standards through code reviews, unit testing, static code analysis, and the adoption or improvement of engineering tools and standards.
• Participate actively in peer code reviews, providing constructive feedback and helping promote maintainable, testable, and scalable solutions.
• Troubleshoot and resolve application issues across environments, including staging and production, with a focus on root-cause analysis and sustainable fixes.
• Work directly with engineering leads, product stakeholders, and project managers to support business operations and project delivery.
• Research, evaluate, and recommend innovative application, automation, and architectural improvements that would benefit the FacilityOS platform.

Skills And Qualifications

• Minimum of 6 years of proven experience in backend .NET Framework / .NET Core web application development using C#.
• Minimum 5 years of experience developing web applications using Angular and Typescript
• Proven ability to quickly understand complex legacy systems, identify key integration points, and contribute effectively with limited ramp-up time.
• Strong experience using object-oriented programming, design patterns, and clean architecture principles to build maintainable, testable software.
• Proven experience writing unit tests and applying quality-focused development practices.
• Proven experience designing and building RESTful services.
• Experience in designing and building cloud-native SaaS and PaaS applications (Azure / AWS). Azure cloud experience will be preferred
• Solid knowledge of Microsoft SQL Server and T-SQL.
• Ability to make sound technical decisions in collaboration with existing engineering teams.
• Proactive, curious, and investigative mindset with strong attention to quality and detail.
• Passion for technology, continuous improvement, and modern engineering practices.
• Ability to self-manage priorities and deliver outcomes with minimal supervision.
• Strong team-player attitude with the ability to collaborate across engineering, architecture, and product stakeholders.
• Hands-on experience with Event-Driven architecture is a plus
• Hands-on experience with Microservices is a plus

Why work at FacilityOS?

We Work Hard And Play Hard And We Do Both With Passion And Respect For One Another. Our Company Promotes a Fast-paced, Fun, Friendly, And Highly Collaborative Work Environment That Provides

• Comprehensive health coverage
• A Hybrid work environment
• Opportunity for advancement and growth
• Catered Events, Snacks, Drinks – You won’t go Hungry!
• Birthday and Life Celebrations
• Two annual parties in a year

FacilityOS Commitment

We believe that a diverse team is the key to innovation and growth. We are an equal opportunity employer that value diversity at our company and encourage all candidates to apply. We do not discriminate based on race, religion, color, national origin, gender, sexual orientation, age, marital status, veteran status, or disability status. FacilityOS will accommodate individuals with disabilities through each stage of the recruitment and selection process. Please advise us of any needs when your interview is booked, and we will do our best to meet your needs. Please note that all candidates must be legally eligible to work in the location in which you applied.

Background and Reference Checks

Any offer of employment may be conditional upon full background checks including a criminal record check, a credit check and employment and educational verifications. A reference check will also be conducted.

We may use artificial intelligence (AI) tools to support parts of the hiring process such as reviewing applications. These tools assist the recruitment team but do not replace human judgment. All advancement and hiring decisions are ultimately made by humans. If you would like more information about how your data is processed, please contact us or click here.

FacilityOS thanks all candidates for their interest, however only those selected to continue in the process will be contacted.