Technical Solutions Engineer

Coinme is part of Polygon Labs, and together we're building the Open Money Stack: one integration for wallets, compliance, fiat on and off ramps, and settlement. Coinme brings the regulated US fiat layer, built over nearly a decade with money transmitter licenses, 50,000+ retail locations, and over $1B processed. The stack is live and fintechs and financial institutions are integrating it now.

This role owns the technical experience of building on us: our API documentation and integration path, the technical answers partners need during a sales conversation, and getting signed partners from kickoff to production. You'd be defining what good looks like, with the room to set the standard and the mandate to hold it. The bar we're setting is the best developer experience in payments: a competent developer working with an AI coding assistant should be able to integrate us without needing to talk to us at all.

This is a senior individual contributor role with deep technical ownership.

• Own the API and integration docs. Rewrite what's wrong, fill what's missing, keep it current as the stack changes
• Build the quickstarts, sample code, and reference architectures that get a developer from nothing to a working integration
• Answer technical questions from partners during sales conversations and during builds, and resolve them yourself rather than passing them to engineering
• Take signed partners live: requirements intake, provisioning once KYB and KYC clear, sandbox testing, webhooks, go-live checks
• Work with the integration program manager on timelines so partners know what's coming and when
• Learn the stack deeply: CaaS ramps, Sequence wallets, Trails, OMSX, bank rails, custodial and non-custodial flows, virtual accounts, deposit addresses, webhooks
• Build demos and sample apps that BD can use to show what the products do
• Push what you learn back into Product and Engineering. You'll see every rough edge in the API before anyone else does
• Automate the repetitive parts of onboarding and provisioning, and use AI tools to move faster on docs and support

You've worked in US payments and you know the rails: fund flows, settlement, reconciliation, and how money actually moves here. US payments has its own rules and its own failure modes, and this role needs someone who has already lived in it.

Beyond that, we're open on where you're coming from. You may have run API integrations for customers at a payments or fintech company, taking them from kickoff to production. Or you may have owned docs, SDKs, or developer support at an API-first payments company. Either path works.

You should also have:

• Hands-on US payments experience. You've worked ACH, RTP, wires, card rails, or an equivalent, and you understand settlement and reconciliation in practice, not in theory
• Real hands-on API skills. You can read logs, debug a broken webhook, reason about auth, and work in Postman or Bruno and Datadog. You don't need to be a software engineer, but you do need to solve problems instead of routing them
• Strong technical writing. You can take a messy system and document it so a stranger can follow it
• Patience for ambiguity. The stack changes weekly, the docs are thin, and nobody is going to hand you a plan
• Comfort using AI tools in your daily work, and an eye for how to make our docs work well for developers who are using them too

• Crypto or stablecoin experience, especially wallets and on-chain settlement. You can learn it here, but having seen it will shorten your ramp meaningfully
• Early-stage or smaller company experience where you've built something without a playbook
• Enough coding to build a demo app
• Experience with a docs platform like Mintlify
• Exposure to KYB and KYC tooling

Check out our AI Usage Guidelines to understand how we approach AI tools during the hiring process.