Senior Backend Engineer - Hybrid, Modernize & Scale APIs

Socket.dev; Annapolis (MD); Hybrid; USD 130,000 - 180,000; Full time

Benefits offered by this job

Comprehensive health coverage

A Hybrid work environment

Opportunity for advancement and growth

Catered Events, Snacks, Drinks – You\'

Birthday and Life Celebrations

Two annual parties in a year

Job summary

FacilityOS is seeking a Sr. Back-End Engineer to design, develop, and modernize backend services within our unified platform. You’ll navigate legacy systems, apply strong architecture principles, and contribute to efficient delivery through collaboration and code quality.

The role is hybrid and requires coming into the office three times per week. Ideal candidates have extensive .NET experience, proficiency in RESTful services, and a passion for scalable SaaS architectures.

Qualifications

• 8+ years of backend .NET Framework / .NET Core development using C#.
• Ability to quickly understand complex legacy systems, identify key integration points.
• Experience applying the Strangler Fig pattern or similar modernization approaches.
• Strong OO design, patterns, and clean architecture for maintainable software.
• Experience writing unit tests and quality-focused development practices.
• Experience designing RESTful services.
• Experience building cloud-native SaaS and PaaS applications.
• Solid knowledge of Microsoft SQL Server and T-SQL.
• Ability to collaborate with existing engineering teams.
• Proactive, curious, and detail-oriented mindset with a focus on quality.
• Passion for technology and modern engineering practices.
• Ability to self-manage priorities and deliver with minimal supervision.
• Strong team-player attitude across engineering, architecture, and product stakeholders.

Responsibilities

• Design, develop, review, and maintain backend web applications and services across the FacilityOS platform.
• Understand platform architecture, legacy components, integration points, and modernization opportunities.
• Collaborate with the engineering team to align with architectural principles and delivery goals.
• Contribute to legacy modernization using incremental, low-risk approaches such as strangler patterns.
• Maintain high code-quality standards through code reviews, unit testing, and tooling.
• Participate in peer code reviews, providing constructive feedback.
• Troubleshoot and resolve issues across environments with root-cause analysis.
• Work with engineering leads, product stakeholders, and project managers to support delivery.
• Research, evaluate, and recommend architectural improvements for the platform.

Skills

C#/.NET

RESTful APIs

Legacy modernization

System design

Unit testing

Cloud-native SaaS/PaaS

SQL Server/T-SQL

Code reviews/mentoring

Job description

FacilityOS is seeking a Sr. Back-End Engineer to design, develop, and modernize backend services within our unified platform. You’ll navigate legacy systems, apply strong architecture principles, and contribute to efficient delivery through collaboration and code quality.

The role is hybrid and requires coming into the office three times per week. Ideal candidates have extensive .NET experience, proficiency in RESTful services, and a passion for scalable SaaS architectures.