Senior API Engineer

Calling all innovators - find your future at Fiserv.

We're Fiserv, a global leader in Fintech and payments, and we move money and information in a way that moves the world. We connect financial institutions, corporations, merchants, and consumers to one another millions of times a day - quickly, reliably, and securely. Any time you swipe your credit card, pay through a mobile app, or withdraw money from the bank, we're involved. If you want to make an impact on a global scale, come make a difference at Fiserv.

Job Title

Senior API Engineer

What does a successful Sr. API Engineer do at Fiserv?

Join a fast-growing team that's revolutionizing how businesses manage B2B payments. As part of the Carat B2B Enterprise Products team, you'll help shape the future of SnapPay-our flagship product that streamlines payment processes by integrating directly with ERP and e-commerce systems. You'll work alongside passionate, cross-functional teammates who thrive on innovation and are driving one of the most dynamic products in Global Business Services



What you will do:

• Lead the charge on evolving and expanding our product use cases to deliver more value to clients and partners.
• Break down monolithic APIs into clean, scalable microservices that make our platform stronger and more flexible.
• Help us choose the right tools and technologies for data processing, while staying alert to security and compliance risks.
• Lead and support your team to deliver high-quality projects on time and on budget.
• Drive our multi-year product roadmap by building and launching new features across the full software development lifecycle.
• Work side-by-side with product, sales, and engineering teams to bring innovative capabilities to market.
• Design and build APIs with high availability and performance-think fast, reliable, and always-on.
• Create clear, detailed design documents that guide development and set us up for success.

What you will need to have:

• Bachelor's Degree (preferably Computer Science or Engineering) or equivalent combination of experience, education and military.
• Minimum 8 years of experience in API development and architecture using REST frameworks, C#, and .NET technologies.
• At least 2 years of hands-on experience with full API lifecycle management using Apigee, including design, development, security, deployment, publishing, monitoring, analytics, and monetization.
• Proven experience implementing and managing API gateways, specifically Apigee, with the ability to design and enforce throttling, quotas, and authentication policies.
• Demonstrated ability to split monolithic APIs into microservices, integrate microservices into ecosystems, and deploy them using Kubernetes, including containerization and security implementation.
• Strong proficiency with Azure services and infrastructure; experience monitoring API usage and predicting scaling needs for high-traffic APIs.
• Ability to analyze and optimize API performance through database partitioning, vertical and horizontal scaling strategies, and resolving architectural bottlenecks.
• Certifications in Azure, Apigee, or related technologies, with experience scaling large-scale web applications and managing both cloud and on-prem Apigee environments.
• Background in managing Azure Kubernetes Clusters.

What would be great to have:

• Master's degree in Computer Science, Information Technology, or a related field
• Experience handling client PII securely in cloud platforms like Azure, AWS, Snowflake, or Google Cloud.
• Deep knowledge of API architecture and MicroServices best practices.
• Strong communication skills-you know how to make complex ideas sound simple.

Important info about this role:

• We're better together. This role is fully on-site.
• In order to be considered, you must be legally authorized to work in the U.S. without need for sponsorship now or in the future.

#LI-SH2

This role is not eligible to be performed in Colorado, California, District of Columbia, Hawaii, Illinois, Maryland, Minnesota, New Jersey, New York, Nevada, Rhode Island or Washington.

It is unlawful to discriminate against a prospective employee due to the individual's status as a veteran.

Please note that salary ranges provided for this role on external job boards are salary estimates made by outside parties and may not be accurate.

Thank you for considering employment with Fiserv. Please:

• Apply using your legal name
• Complete the step-by-step profile and attach your resume (either is acceptable, both are preferable).

Our commitment to Equal Opportunity:

Fiserv is proud to be an Equal Opportunity Employer. All qualified applicants will receive consideration for employment without regard to race, color, religion, national origin, gender, gender identity, sexual orientation, age, disability, protected veteran status, or any other category protected by law.

If you have a disability and require a reasonable accommodation in completing a job application or otherwise participating in the overall hiring process, please contact Please note our AskHR representatives do not have visibility to your application status. Current associates who require a workplace accommodation should refer to Fiserv's Disability Accommodation Policy for additional information.

Note to agencies:

Fiserv does not accept resume submissions from agencies outside of existing agreements. Please do not send resumes to Fiserv associates. Fiserv is not responsible for any fees associated with unsolicited resume submissions.

Warning about fake job posts:

Please be aware of fraudulent job postings that are not affiliated with Fiserv. Fraudulent job postings may be used by cyber criminals to target your personally identifiable information and/or to steal money or financial information. Any communications from a Fiserv representative will come from a legitimate Fiserv email address.