Full-Time

Senior Software Engineer

C#/PHP

Posted on 11/14/2025

NMI

NMI

501-1,000 employees

White-label payment gateway for partners

Compensation Overview

$90k - $137k/yr

Remote in USA

Remote

Category
Software Engineering (1)
Required Skills
PHP
SQL
C#
DevOps
Requirements
  • 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, with 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 (e.g. OWASP, PCI)
  • Excellent communication skills, with a proven ability to mentor others, contribute to a strong team culture, and work with others across teams to move projects forward
  • Experience designing and architecting scalable, distributed systems with consideration for performance, reliability, and maintainability
  • 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
Responsibilities
  • Design, develop, and maintain core billing and invoicing systems using C# and PHP technologies
  • Take ownership of architectural and design decisions for billing system components
  • Lead technical discussions, participate in code reviews, and drive best practices in maintainability and performance
  • Actively mentor and support the growth of junior team members
  • Lead improvements to CI/CD pipelines and development processes
  • Implement monitoring, logging, and alerting systems to proactively identify and resolve issues
  • Optimize database queries and system architecture to handle growing merchant and transaction volumes
  • Implement robust security measures to protect sensitive payment and merchant data and ensure compliance with PCI DSS standards
  • Communicate project status, risks, and technical decisions effectively to both technical and non-technical stakeholders
  • Collaborate closely with Product Owners, Developers, and QA teams to ensure successful product releases
  • Proactively identify, assess, and mitigate risks, including security risks, throughout the software development lifecycle
  • Provide feedback and resolutions to escalated support issues
  • Research and evaluate new technologies and methodologies to improve system performance and developer productivity
Desired Qualifications
  • Experience with logging systems (such as Logz.io) and optimizing logs preferred
  • Experience with containerization (e.g. Kubernetes, Docker, etc.) preferred
  • Experience with monitoring and alerting systems (e.g. DataDog, NewRelic, etc.) preferred
  • Experience with CI/CD pipelines, automated testing, and deployment processes preferred

NMI provides white-labeled payment gateway technology for ISOs, VARs, ISVs, and payment facilitators. Its platform enables partners to offer their own branded payment gateway services to merchants, while handling secure, real-time omnichannel payments (in-store, online, mobile, unattended). Partners access a merchant portal for transaction management, reporting, and analytics. NMI earns revenue through partner fees such as transaction fees, monthly fees, and value-added services. The company differentiates itself by offering a white-label, omnichannel payment gateway with a robust set of tools that partners can rebrand as their own, allowing them to maintain their brand identity while leveraging NMI’s infrastructure. The goal is to empower partner networks to deliver seamless payment services under their own brands at scale.

Company Size

501-1,000

Company Stage

Private

Total Funding

$620M

Headquarters

Schaumburg, Illinois

Founded

2000

Simplify Jobs

Simplify's Take

What believers are saying

  • Steven Pinado appointed CEO to drive next growth phase.
  • LANDI M20SE partnership launches compact Tap to Pay Android device.
  • Bill Connect embeds payments into QuickBooks and Xero for SMBs.

What critics are saying

  • Stripe erodes market share with superior developer tools and pricing.
  • Shopify Payments captures eCommerce volumes via proprietary POS sync.
  • Plaid open banking APIs bypass NMI through direct ACH integrations.

What makes NMI unique

  • NMI delivers white-label payment gateway for ISOs, VARs, ISVs, and payment facilitators.
  • iSpyFraud and tokenization provide advanced security beyond standard gateways.
  • Omnichannel platform supports in-store, online, mobile, and unattended payments.

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Benefits

Health Insurance

Dental Insurance

Vision Insurance

Unlimited Paid Time Off

Paid Holidays

Remote Work Options

Company Equity

Growth & Insights and Company News

Headcount

6 month growth

0%

1 year growth

-1%

2 year growth

0%
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The Financial Technology Report
Sep 2nd, 2025
NMI Appoints Steven Pinado as CEO to Lead Next Phase of Growth

NMI appoints Steven Pinado as CEO to lead next phase of growth.

Retail Solutions Providers Association (RSPA)
Jun 4th, 2025
LANDI and NMI Expand Partnership with Launch of LANDI M20SE: A Compact, Cost-Effective Android Device Configured for Tap to Pay

LANDI and NMI expand partnership with launch of LANDI M20SE: A compact, cost-effective Android device configured for Tap to Pay.

Financial Technology Insights
Mar 27th, 2025
NMI Launches Tap to Pay on Google Play Store

NMI, a global leader in embedded payments infrastructure, announces the availability of its new Tap to Pay solution on the Google Play Store.

PYMNTS
Jan 23rd, 2025
Nmi Embeds Payment Functionality Into Popular Accounting Software

Embedded payments infrastructure provider NMI has launched a new extension for use with its NMI Payment Gateway that embeds payment functionality directly into popular accounting software like QuickBooks and Xero. This new extension, Bill Connect, is powered by Biller Genie, NMI said in a Thursday (Jan. 23) press release. Bill Connect helps the small and medium-sized businesses (SMBs) that use the popular accounting software automate and streamline invoicing, accept secure payments and automate reconciliation — all within a single platform and without a need for enterprise resource planning (ERP) systems — according to the release

INACTIVE