Senior Developer

It's fun to work in a company where people truly BELIEVE in what they're doing!

Fullsteam is a leading provider of vertical software and embedded payments technology dedicated to helping businesses flourish by providing their customers with seamless experiences. With a dynamic and growing team of over 1,900 employees, we are committed to driving innovation and delivering best-in-class software and payment solutions that empower small and medium-sized businesses across numerous industries. Our purpose is to help our customers grow their businesses and delight their customers. Join us and be a part of a forward-thinking company that values growth, excellence, and the success of our clients.

RTO Pro, part of the Fullsteam organization, provides its customers with Rent-to-Own contract management software as well as retail and inventory management. Saas offerings include online billing and payments, business management, customer communication, and productivity features.

We are seeking an experienced Full-Stack Engineer to own features end-to-end across a diverse technology stack, including ASPNET webforms, ASP.NET backend services, legacy VB6 components, and various data layers. You will design, implement, test, deploy, and monitor robust solutions while managing key products such as Webpay, SMS, Automated Collections (voice), IVR, and desktop applications.

Primary Responsibilities:

• Own features end-to-end — from technical design and implementation to testing, deployment, and observability — across ASP.NET Webforms, ASP.NET backend, WCF APIs, VB6, and data layers.
• Troubleshoot and resolve integration issues with other software
• Collaborate with support and sales to deliver bug resolution, new features, and functionality changes
• Manage Webpay, SMS, ACM (Automated Collections Module), IVR and desktop products
• Design and integrate APIs (REST): write clear contracts, handle auth, rate limiting, and error semantics; integrate third-party APIs when needed.
• Develop backend services in .NET (.NET Framework, .NET Core)
• Work with databases (MSSQL, Firebird), including query optimization, data merges, indexes, and pragmatic use of ORMs.
• Contribute to mobile development (.NET Maui, conversion of Xamarin Forms)
• Level-up DevOps practices: contribute to CI/CD (GitHub Actions), environment configs/secrets, basic IaC where appropriate, and zero-downtime deploys.
• Instrument and observe applications (logs/metrics/traces)
• Champion security basics (OAuth/OIDC/JWT, session management, update legacy authentication solutions
• Raise the bar on code quality via thoughtful PR reviews, reusable abstractions, and incremental refactors.
• Collaborate tightly with Product and Design to shape scope, break work into milestones, and deliver predictable, incremental value.

Skills & Competencies:

• Web Development / Full stack / .NET  (Senior Level)
• Webpay site is in .NET 4.7.2 and MSSQL
• APIs development and management
• Web forms development and management
• Preferred: Experience with VB6 and .Net - Desktop Development
• Familiarity with Azure Infrastructure
• Familiarity with InstallShield

Minimum Qualifications:

• Bachelor’s degree or equivalent practical experience.
• 5+ years professional experience as a Full-Stack or Front-End-heavy Developer.
• Proven track record shipping production features
• Comfortable with SQL and at least one relational DB; able to reason about data models and migrations.
• Experience integrating and securing REST APIs.
• Solid grasp of Git/GitHub workflows, testing, and CI/CD.
• Clear, proactive communication; able to own projects with minimal oversight while collaborating in a team.

Salary range: $100,000 - $140,000 USD

Fullsteam supports an inclusive workplace that values diversity of thought, experience, and background. Fullsteam is an Equal Opportunity/Affirmative Action employer. All qualified applicants will receive consideration for employment without regard to race, religion, color, national origin, ancestry, age, physical or mental disability, sex, sexual orientation, gender identity/expression, pregnancy, veteran status, marital status, creed, status with regard to public assistance, genetic status or any other status protected by federal, state, or local law.