Senior Software Developer, Partner API (.NET)

Swyfft; United States; Remote; USD 140,000 - 180,000; Full time

Benefits offered by this job

Medical, dental, vision

401(k) with generous match

PTO 20 days

Generous holidays and choose-your-own

Job summary

Swyfft is hiring a senior API engineer to own the Partner API end to end. You will design, evolve, and document a best-in-class developer experience on top of a robust insurance domain, working closely with external partners and their engineers.

You will implement stable contracts, secure multi-tenant access, and maintain accurate OpenAPI specs while collaborating across teams to deliver reliable integrations.

Qualifications

• 7+ years of backend development with 3+ years in partner-facing/public API.
• Experience designing REST APIs used by external developers in production.
• Strong understanding of API security, multi-tenancy, and versioning.
• Ability to document contracts clearly for external developers.

Responsibilities

• Own the Partner API contract end to end: design, versioning, deprecation, backward compatibility.
• Design consistent API resources and build a stable translation layer for internal changes.
• Collaborate with partner engineering teams to support integrations.
• Define error responses, idempotency, authentication, rate limiting, and usage metrics.
• Keep OpenAPI spec and developer docs accurate; add contract tests for breaking changes.
• Write/review production C# code and ship through the release process.

Skills

REST API design

OpenAPI/contract-first

API security

Documentation writing

Education

Bachelor’s degree in CS/CE

Tools

ASP.NET Core

SQL Server

Azure

OpenAPI tooling

Job description

Swyfft writes homeowners and commercial package insurance, sold mostly through independent agents. Our platform takes a property address, pulls in data about the building and its risks, and returns a bindable quote in seconds. Behind that is the full policy lifecycle: rating, underwriting rules, policy issuance, endorsements and renewals, and claims.

The stack is C#/.NET, TypeScript, and SQL Server, running largely on Azure. It’s a real production system with real history: some of it is modern, some of it is the kind of code you inherit when a company has been shipping for years, and part of the job is making it better without breaking things people depend on every day.

The technology team is about 30 people across development, support, IT, and QA. That’s small enough that your work is visible and you won’t spend months waiting on approvals, and large enough that you’re not the only person who knows how anything works. If you like hard domain problems, working close to the people who use what you build, and seeing your changes in production quickly, we’d like to talk.

About the Position:

Swyfft’s Partner API lets our partners create and manage Swyfft insurance quotes directly from their own software. We’re hiring a senior engineer to own it full time and make it a best-in-class developer experience: intuitive, consistent, well documented, and dependable as it evolves. You’ll design clean, stable resources on top of a rich insurance domain and work closely with our partners’ engineering teams. You’ll learn our codebase as you go; we’re hiring for your API experience.

*Please note that we are unable to provide sponsorship of any kind at this time.

*This position is a 100% U.S. based remote opportunity that can be based in one of the following states AL, AZ, FL, GA, KY, LA, MA, MO, NC, NJ, NY, OH, OR, PA, SC, TX, UT, VA, WA, WI.

*Some travel for team meetings and training may be required.

Key Responsibilities: (What you’ll be asked to do)

• Own the Partner API contract end to end: resource design, versioning, deprecation, and backward compatibility across releases.
• Design clear, consistent API resources, and build the translation layer that keeps the public contract stable as our internal systems evolve.
• Work directly with our partners’ engineering teams to support their integrations, including partner-specific work on our side when an integration calls for it.
• Design consistent error responses, idempotency, authentication, and rate limiting, along with the usage metrics that show how partners use the API.
• Keep the OpenAPI spec and developer documentation accurate and current, with contract tests that catch breaking changes before partners do.
• Write and review production C# code, partner with QA and product, and ship through our release process.

The Successful Candidate: (what we're looking for)

• You’ve designed, shipped, and run a REST API used by external developers in production, and kept it backward compatible through versions. A few years on a well-known public API (payments, e-signature, communications) is exactly the kind of background we mean.
• You think contract-first: OpenAPI, schema evolution, deprecation policies, and changelogs.
• You know API security and multi-tenancy: API keys or OAuth 2.0 client credentials, scopes, tenant isolation, and quotas.
• You’ve put a clean public contract in front of a complex internal domain and can explain the tradeoffs.
• You like working with other companies’ developers, and you write clearly for them in docs and email.
• You know how to get the most out of AI coding agents; our team uses them every day.

Some Requirements:

• 7+ years of experience as a backend developer, including 3+ years building or maintaining a partner-facing or public API.

Education:

• A Bachelor’s degree in Computer Science, Computer Engineering, or equivalent work experience is required.

Computer Skills:

• Fluent in C#, ASP.NET Core, and SQL Server (MSSQL); experience with Azure.
• Experience using video and chat technology (MSTeams & Slack).

Nice to Have:

• Insurance or fintech industry experience, including ACORD standards.
• API gateway experience (Azure API Management or similar), SDK generation, and webhooks.

Other:

• Reliable high-speed internet connectivity required.
• Designated quiet work from home space.

Actual compensation for this position will vary based on skills, qualifications, and experience. The range reflects annual compensation (as applicable) and does not include bonuses or other incentives that the company may choose to pay at its sole discretion.

In addition to base compensation Swyfft offers a comprehensive benefit package.

We Have a Great Benefits Package!

• Medical, Dental, and Vision
• Short- and Long-Term Disability (Company Paid)
• Voluntary Long-Term Disability
• Employee Life & AD&D (Company Paid)
• Voluntary Employee, Spouse, and Child Life & AD&D
• Healthcare, Dependent Care and Transit FSA, and Healthcare Savings Account (HSA)
• 401K with a generous matching contribution and no vesting schedule
• 20 days of PTO annually (prorated based on hire date)
• Company Paid Holidays and 2 "Choose Your Own Holidays"

It is the policy of Swyfft to provide equal employment opportunities to all employees and applicants for employment without regard to race, religion, color, ethnic origin, gender, gender identity, age, marital status, veteran status, sexual orientation, disability, or any other basis prohibited by applicable federal, state, or local law. EOE/AA/M/D/V/F.

If you require accommodations during the application or interview, please contact Human Resources at [e-mail], and we will make every effort to accommodate your needs.