Software Engineer, Backend Developer

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.

We are looking for a highly capable Back-End 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.

• Design, develop, review, and maintain backend web applications and services across the FacilityOS platform under the guidance of senior engineering and architecture direction.

• Quickly develop a working understanding of existing platform architecture, legacy components, integration points, and modernization priorities.

• Collaborate with senior engineers, architects, and the broader engineering team to make sound technical decisions aligned 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.

• Build maintainable, testable, and scalable backend solutions using object-oriented programming, design patterns, and established engineering standards.

• Maintain high code-quality standards through unit testing, peer code reviews, static code analysis, and consistent use of agreed-upon development practices.

• Participate actively in peer code reviews by providing constructive feedback and incorporating feedback from others.

• Troubleshoot and resolve application issues across environments, including staging and production, with a focus on root-cause analysis and sustainable fixes.

• Work with engineering leads, product stakeholders, and project managers to support business operations and project delivery.

• Research, evaluate, and recommend application, automation, and architectural improvements that could benefit the FacilityOS platform.

• Minimum of 4–6 years of proven experience in backend .NET Framework / .NET Core web application development using C#.

• Demonstrated ability to understand existing systems, legacy codebases, integration points, and business logic with limited ramp-up time.

• Practical experience contributing to legacy modernization, refactoring, or incremental replacement efforts; experience with the Strangler Fig pattern or similar modernization approaches is strongly preferred.

• Strong working knowledge of object-oriented programming, design patterns, and clean code principles.

• Experience writing unit tests and applying quality-focused development practices.

• Proven experience designing, building, and maintaining RESTful services.

• Experience working with cloud-native SaaS or PaaS applications.

• Solid knowledge of Microsoft SQL Server and T-SQL.

• Ability to make sound technical recommendations in collaboration with senior engineers and 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 assigned priorities and deliver outcomes with limited…