Finix is the smartest way for businesses to own, manage, and monetize payments. Built by payments experts from Klarna, PayPal, and Worldpay, Finix is trusted by companies like Lightspeed POS Inc., Passport, and Clubessential to build and scale their payments infrastructure. Headquartered in San Francisco, with an additional office in Cincinnati, Ohio, Finix is a privately held company funded by American Express Ventures, Bain Capital Ventures, Homebrew, Inspired Capital, Lightspeed Venture Partners, Sequoia Capital, Visa, and others. To learn more, visit



Senior API Designer/ API Architect

About the Role: The API Designer is the standard bearer for APIs at Finix and will propel Finix’s mission of enabling software companies to become payment companies. They will marry their knowledge of Finix’s business, developer needs, and principles of API design to create a modern, inviting, and comprehensible API. The API design should make payments accessible to developers and help them accomplish their integrations accurately and efficiently. The API designer will contribute to best-in-class documentation, tutorials, code libraries, and sample code. They will build or buy tools to allow product managers and developers to create standards compliant APIs. They will also help modernize existing APIs to meet needs. You Will
  • Take primary responsibility for designing new APIs and upgrading existing APIs to be compliant with standards
  • Work with UI product managers to define APIs that are used specifically to power the UI; also work with the reporting product manager to create a standard API design pattern for reporting
  • Collaborate with functional product managers and integration engineers to understand payments use cases
  • Ensure compliance of APIs to the OpenAPI specification and standards
  • Write tests to ensure compliance with OpenAPI specifications
  • Create and maintain demo scripts to train Support and Sales Engineering
  • Assist Sales Engineering in answering in-depth technical questions about using the API
  • Take responsibility for the accuracy and completeness of all developer documentation; work with technical writing on the same. API references (not guides)
  • Manage the process of updating APIs ensuring that they don’t break existing customer implementations
  • Liaise between PMs and Engineering Leads and align vision on API. Do API design component and have strong project and people skills to ensure this all gets stitched together
  • Evolve the APIs to create multiple self-contained product modules that can be used by the customer independently or together
You Have:
  • You have experience designing and building APIs in other companies which have seen a lot of scale
  • You have the ability to write small amounts of code to test APIs
  • Strong written, verbal, and presentation skills which help you talk to business and technical customers
  • You love to build and ship products
  • You understand not only today’s use cases but also future use cases for the API; you are able to design APIs that have “runway” i.e. evolve naturally to accommodate future use cases
  • Beyond just shipping new products, you obsess about continuous product improvement
  • You do whatever it takes to make your product and team successful, no matter how big or small the issue may be
  • You can turn incomplete, conflicting, or ambiguous inputs into solid action plans
  • 5+ years experience in a product role in a company that makes mission-critical infrastructure (think AWS for e.g.)
  • 2+ years experience in an engineering role
  • Experience managing technical software products from kick-off to ship
  • Degree in a technical or quantitative field (e.g., Computer Science, Economics, Statistics, Sciences, Engineering)
  • Financial products experience
*Note: a take-home design exercise will be a component in the interview process. About our benefits and perks Finix offers a comprehensive benefits package for all employees. Benefits are effective on the 1st of the month after your start date.
  • Health: We offer a variety of health insurance plans with two major carriers (UHC for national coverage and Kaiser as an additional option for CA). Finix pays 90% of the employee premium and 50% of the dependent premium for whichever plan you choose. The remainder of the premium will be deducted from your paycheck pre-tax.
  • Dental: PPO dental plan through Beam Dental, one of the best new dental carriers with national coverage. Finix covers 90% of the employee premium and 50% of the dependent premium.
  • Vision: Vision plan through VSP. Finix covers 90% of the employee premium and 50% of the dependent premium.
  • Life / AD&D: Company-paid Life/AD&D insurance with coverage for 1x your annual salary.
  • Short-term / Long-term Disability: Company-paid short-term and long-term disability insurance.
  • Medical and Dependent Care FSAs: Pre-tax Flexible Spending Accounts for out-of-pocket medical or dependent care expenses.
  • Commuter Benefits: Pre-tax account for parking or transit expenses.
  • 401k: 401k account through Guideline.
  • Paid Time Off: In addition to federal holidays, we offer accrued time off of up to 15 days per calendar year. Sick time is accrued separately at up to 9 days per calendar year.
Finix is an equal opportunity employer and values diversity. We do not discriminate on the basis of race, religion, color, national origin, gender, sexual orientation, age, marital status, veteran status, or disability status.