Jobs in O Fallon, MO
80 open roles — posted here, and found on employers' own careers sites.
11 new this week, 0 the week before, counting only boards we were already tracking.
Senior Specialist, Payroll Tax
Mastercard
Full-time · O Fallon, MO · $85,000 – $132,000
This role leads payroll tax compliance and integration activities during corporate mergers and acquisitions, managing tax registrations, employee setup, vendor coordination, and post-implementation stabilization. It suits someone with deep payroll tax expertise who thrives managing complex multi-jurisdictional projects through organizational change.
Listed on Mastercard’s careers site · Apply there ↗
Software Engineer II - Decision Management Program
Mastercard
Full-time · O Fallon, MO · $92,000 – $147,000
This role builds and maintains backend services for Mastercard's enterprise notification platform, handling high-volume transaction events across fraud and security products. It suits mid-level engineers comfortable with Java microservices, event-driven architectures, and production support responsibilities in a large distributed-systems environment.
Listed on Mastercard’s careers site · Apply there ↗
Senior Software Engineer
Mastercard
Full-time · 24 locations · $115,000 – $184,000
A senior-level individual contributor role focused on designing and building scalable distributed systems while mentoring junior engineers. This position suits experienced Java backend developers who want to take on architectural responsibilities and grow as technical leaders without moving into pure management.
Listed on Mastercard’s careers site · Apply there ↗
Lead PostgreSQL Engineer
Mastercard
Full-time · O Fallon, MO · $122,000 – $207,000
Lead a team designing and operating Mastercard's enterprise PostgreSQL databases at scale, combining deep database expertise with platform engineering practices to build secure, highly available services. This role suits experienced database engineers ready to drive technical strategy and mentor others across cloud infrastructure and distributed systems.
Listed on Mastercard’s careers site · Apply there ↗
Vice President, Software Engineering
Mastercard
Full-time · 3 locations · $254,000 – $407,000
This role leads Mastercard's Developer Workbench platform, a unified engineering experience that integrates tools, AI-assisted coding, and development workflows across the enterprise. It suits experienced engineering leaders who have built or scaled developer platforms and can drive adoption of modern engineering practices at scale.
Listed on Mastercard’s careers site · Apply there ↗