Senior Software Engineer

NMI

. Design, develop, and maintain core billing and invoicing systems using C# and PHP .

Posted 10/14/2026full-timeRemote • United States, CanadaSenior💰 $115,000 - $130,000 per yearWebsite

Core Competencies

Role fit

Core Competencies

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Demonstrates advanced proficiency in C# and PHP for designing and maintaining billing systems, with a strong focus on security, compliance, and performance optimization. Capable of leading technical discussions, mentoring team members, and collaborating effectively across diverse teams.

Highest-signal resume keywords

C# ProgrammingPHP DevelopmentDatabase Design and OptimizationSecurity Best PracticesCI/CD Pipeline Improvement

ATS Keywords

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Applicant Tracking System Keywords

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Hard Skills

Object-Oriented Design PrinciplesDesign PatternsPerformance TuningCode ReviewSoftware Development Lifecycle Risk Mitigation

Soft Skills

Excellent CommunicationMentoringCollaboration

Tools & Technologies

ClaudeCursorMonitoring SystemsLogging SystemsAlerting Systems

Certifications & Qualifications

Bachelor's Degree in Computer SciencePCI DSS Compliance Knowledge

Industry Keywords

Agile EnvironmentScalable SystemsDistributed SystemsOWASPPayment Data Security

Tech Stack

Tools & technologies

Distributed SystemsPHP

About the role

Key responsibilities & impact

Design, develop, and maintain core billing and invoicing systems using C# and PHP
Use Claude and Cursor across design, implementation, testing, refactoring, and comprehension of large existing codebases
Review AI-generated code for correctness, security, performance, and maintainability
Own architectural and design decisions for billing system components
Lead technical discussions, participate in code reviews, and drive maintainability and performance best practices
Mentor junior team members, including coaching on effective and safe AI tool usage
Lead improvements to CI/CD pipelines and development processes
Implement monitoring, logging, and alerting systems
Optimize database queries and system architecture for growing merchant and transaction volumes
Implement security measures for sensitive payment and merchant data and ensure PCI DSS compliance
Communicate project status, risks, and technical decisions to technical and non-technical stakeholders
Collaborate with Product Owners, Developers, and QA teams on product releases
Identify, assess, and mitigate software-development-lifecycle risks
Provide feedback and resolutions to escalated support issues
Research and evaluate technologies and methodologies to improve performance and developer productivity

Requirements

What you’ll need

Bachelor's degree in Computer Science or equivalent experience
Minimum of 5 years of experience developing complex software applications in a collaborative, agile environment
Advanced proficiency in C# and/or PHP
Strong understanding of object-oriented design principles and design patterns
Advanced experience with database design, optimization, and performance tuning
Strong knowledge of security and compliance best practices, including OWASP and PCI
Excellent communication skills and proven ability to mentor others and work across teams
Experience designing and architecting scalable, distributed systems
Ability to translate complex business requirements into technical solutions
Proven track record of code reviews and maintaining code quality standards
Proven ability to understand, debug, and enhance complex existing systems with limited documentation and evolving requirements
Hands-on experience building production software with Claude and Cursor
Sound judgment about appropriate use and limitations of AI tooling
All offers subject to satisfactory background and financial checks
Must have the legal right to be employed in the United States

Benefits

Comp & perks

A remote first culture!
Competitive compensation and benefits
Personal growth and advancement opportunities
Flex PTO & dedicated sick time
Health, Dental and Vision Insurance
Life, ADD, Short-term and Long-term Disability insurance
401k matching up to 4% after two months of service
Flexible Spending Account
Paid Parental Leave
Company volunteer days
Employee referral program
Bonusly colleague recognition
Diversity, Equity & Inclusion initiatives, affinity groups, open forums, and inclusion and belonging surveys