Senior Software Engineer - Platform, API

Meanwhile; San Francisco, Northern (CA, KY); Hybrid; USD 180,000 - 240,000; Full time

Benefits offered by this job

Health, dental & vision benefits

Meals provided in office

Off-site company events

Job summary

Meanwhile is seeking a Senior Software Engineer to take ownership of the public API and MCP server, expanding the platform for external integrations. You will design, implement, and secure the external surface, ensuring scalable, well-documented interfaces used by brokers, partners, and auditors.

Expect close collaboration with partners and internal teams, and an emphasis on thoughtful API contracts. The role requires strong Python and PostgreSQL experience, API security expertise, and a focus

Qualifications

• 10+ years of professional software engineering experience.
• Substantial experience designing and operating public or partner-facing APIs.
• Depth in API security: OAuth 2.0 / OIDC, credentials and key management.
• Experience scaling an API surface in production: rate limiting, caching, latency, degradation.
• Strong documentation skills for external developers without hand-holding.
• Strong Python and relational database experience (PostgreSQL).
• Experience supporting external integrators and feeding learnings back into design.
• Fluency with AI development tools and prudent judgment on outputs.
• Comfort with ambiguity and self-teaching attitude.
• Low-ego approach with a high bar for precision.
• Based in the SF Bay Area with ability to work in-office 3 days/week.

Responsibilities

• Design and build Meanwhile's public API - resource modeling, versioning, deprecation policy, and error taxonomy.
• Build MCP server exposing capabilities to AI agents with safe boundaries.
• Own authentication and authorization model for external access (OAuth 2.0 / OIDC).
• Implement controls for safety: rate limits, quotas, input validation, and audit logging.
• Design for scale: latency budgets, caching, backpressure, SLOs, observability.
• Write documentation, references, and integration guides for third parties.
• Develop sandbox, example integrations, changelog, and partner support paths.
• Collaborate with API engineering teams to shape coherent external contracts.
• Write production Python code against PostgreSQL; SDKs in other languages as adoption grows.
• Use AI tooling judiciously; require human review when needed.
• Participate in business-hours on-call rotation.

Skills

API design

Public APIs

Python

PostgreSQL

OAuth 2.0 / OIDC

AI tooling

Documentation

Developer experience

Tools

OpenAPI tooling

API gateway

SDKs

Job description

About us For institutions Press Login Meanwhile

Senior Software Engineer - Platform, API

Full-time · Engineering · San Francisco, CA (3 days/week in office)

A senior engineer to take Meanwhile's public API and MCP server from early prototype to the contract outsidepartners, and their agents, build against.

We are opening the Meanwhile platform up. Brokers, distribution partners, administrators, and auditors all need tointegrate with us directly, and increasingly they want to do it through agents rather than through a browser.We're building two things to support that: a public API, and an MCP server that exposes the platform'scapabilities to AI agents safely.

The work starts from an early internal prototype, built to serve one of our own integrations, and your job is totake it to a real external product. This is a first-version problem, which is the interesting part and the hardpart. The contracts you design will be depended on by outside parties who cannot be asked to redeploy on yourschedule, in a regulated business where the data crossing the boundary is policyholder and financial data. Gettingthe resource model, the auth model, and the versioning story right at the start is worth more than any amount ofcleanup later.

You'll own the public surface end to end: design, implementation, security, performance, documentation, and thedeveloper experience of the people building against it. We're looking for someone who wants to go deep here as anindividual contributor - the person who owns how the outside world talks to Meanwhile.

What You’ll Do

• Design and build Meanwhile's public API - resource modeling, versioning and deprecation policy, idempotency,pagination, error taxonomy, webhooks and event delivery
• Build our MCP server, exposing platform capabilities as tools agents can use safely: least-privilege scoping,clear tool boundaries, and human-in-the-loop on state-changing operations
• Own the authentication and authorization model for external access - OAuth 2.0 / OIDC, scoped credentials,tenant and partner isolation, key lifecycle and rotation
• Build the controls that keep a public surface safe and predictable: rate limiting and quotas, abuse detection,input validation, request signing, comprehensive audit logging
• Design for scale and degrade gracefully - latency budgets, caching, backpressure, load shedding, SLOs, and theobservability to know when any of it is slipping
• Write the documentation, reference, and integration guides third parties actually build from, and keep themaccurate as the API evolves
• Build the surrounding developer experience: sandbox environment, example integrations, changelog, and a supportpath for partners who are stuck
• Partner with the engineering teams behind the API to shape internal services into a coherent external contractrather than leaking our internals
• Write production code in Python against PostgreSQL, with client SDKs in other languages a possibility asexternal adoption grows
• Use AI tooling to move faster, with the judgment to know when its output needs a second look
• Participate in business-hours on-call rotation shared across the engineering team (no nights/weekends)

How We Work

We don't have product managers. You'll work directly with the partners and internal teams who depend on the API tounderstand what they need, shape the contract, and explain the tradeoffs - that discovery is part of the job, notsomething that happens before it reaches you.

We lean into AI tooling and you'll have it. It's a real accelerant here, and we expect you to use it well. But apublic API is the one surface where mistakes are permanent: once a partner has built against a contract, you livewith it. The work still rests on thinking carefully about the interface, the security model, and the failuremodes.

Qualifications

Required

• 10+ years of professional software engineering experience
• Substantial experience designing and operating public or partner-facing APIs - not just internal services, butinterfaces consumed by engineers outside your company
• Depth in API security: authentication and authorization models, OAuth 2.0 / OIDC, credential and key management,tenant isolation, common attack classes against public endpoints
• Experience scaling an API surface in production - rate limiting, caching, latency and throughput work, gracefuldegradation, incident response on a surface you can't take down
• Demonstrated ability to produce documentation third parties can integrate from without hand-holding, and agenuine interest in developer experience as a first-class product concern
• Strong Python and relational database experience (PostgreSQL or equivalent)
• Experience supporting external integrators - triaging their problems, and feeding what you learn back into thedesign
• Fluency with AI development tools, and the judgment to evaluate what they produce
• Comfort with ambiguity and a habit of teaching yourself the domain
• Low-ego approach and a high bar for precision
• Based in the SF Bay Area with the ability to work in-office 3 days per week

What Makes You Stand Out

• Experience building an MCP server, or otherwise designing tool interfaces for AI agents
• Experience launching a v1 public API at a company that hadn't had one before, including the versioning anddeprecation policy that came with it
• Fintech, insurance, or other regulated-industry experience, particularly where partner data sharing hadcontractual or regulatory constraints
• Event-driven and webhook delivery experience - at-least-once semantics, retries, replay, consumer-sideidempotency
• SDK authoring, OpenAPI tooling, or API gateway design
• Interest in or experience with cryptocurrency/blockchain technologies
• Startup experience on small engineering teams (<10 people)

Technical Environment

• Backend: Python
• Database: PostgreSQL
• CI/CD: GitHub Actions
• Cloud: AWS

Why Join Us?

• Define the contract: Set the public interface for a platform that doesn't have one yet, without inheritinga decade of someone else's decisions
• Real Ownership: You'll own the entire external surface - API, MCP server, docs, and developer experience
• Unique Domain: Build the integration layer for first-of-their-kind Bitcoin-denominated financialproducts
• Direct Influence: Small team, flat organization, direct access to leadership
• Ahead of the curve: Agent-facing interfaces are being figured out right now, and you'd be doing thatwork rather than reading about it
• Benefits:
  • Fully covered health, dental, and vision for you and your family
  • Meals provided in office
  • Two annual company off sites (fully paid)

Our Values

• Keep your word. Honor commitments to clients and each other.
• Build for the future. We measure success in decades; look ahead without losing sight of what matterstoday.
• Be curious. Our advantage is understanding the world, the market, and each other.
• Have fun. Enjoy the work. Find humor where you can. Rest when needed. Say when you need help.

Company & Funding

We're building the world's largest long-term insurer, using digital money and AI to serve billions of peopleprofitably. We want anyone, anywhere, to be able to save for their future, protect their family, and buildwealth across generations.

We face a once-in-a-century opportunity to build a vertically integrated life (re)insurer. Our product offeringsare globally unique, making it possible for us to scale our balance sheet, build modern systems from scratch,and then directly compete to win a market that is 3% of global GDP.

We've raised over $140M to date. Sam Altman and Lachy Groom led our initial raise, and they've since been joinedby leading investors in AI, insurance, and Bitcoin, including Northwestern Mutual, Apollo, Bain Capital,Pantera, Haun, Framework, Fulgur Ventures, MS&AD, Mouro, Stillmark, and Wences Casares.

Our Bermuda operating subsidiary holds the the world's only license to issue life insurance denominated entirelyin Bitcoin. It's also the only company in the world with audited financials stated in Bitcoin. (If you join us,you can expect to do a lot of things no one's ever done before.)

About us Press Financials Careers Contact us

150 Sutter Street #520
San Francisco, CA 94104

Canon's Court, 22 Victoria Street
Hamilton HM 12, Bermuda

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Carrier status

Meanwhile Insurance Bitcoin (Bermuda) Limited (\"Meanwhile\") is a life insurance carrier licensed and regulated by the Bermuda Monetary Authority.

Bermuda jurisdiction

Applications for Meanwhile's insurance products will only be received and reviewed by the company at its offices in Bermuda, and all offers and sales of its insurance products will only be made in Bermuda. Meanwhile does not conduct insurance business in any other jurisdiction.

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The material on this website should not be construed as any solicitation to buy, offer to sell, or submit an application for the purchase of any insurance product in any jurisdiction other than Bermuda. Meanwhile may initially make hypothetical illustrations available.

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These should be construed as illustrative only and do not constitute a proposal to enter into an insurance contract or an undertaking to offer insurance coverage under any specific terms and conditions in any jurisdiction. Only personnel of Meanwhile are authorized to make representations regarding its insurance products. Any materials which have not been prepared by Meanwhile should not be considered as representations by Meanwhile.

Legal and tax advice

Neither Meanwhile Insurance Bitcoin (Bermuda) Limited nor its affiliates Meanwhile Services (Bermuda) Limited and Meanwhile Incorporated, are lawyers or accountants. They do not provide legal or tax advice. You are wholly responsible for obtaining your own legal and tax advice.