{"schemaVersion":"jobsearcher.job.v1","id":"aec4a528ee37df2ccd46da36","url":"https://jobsearcher.com/jobs/aec4a528ee37df2ccd46da36","canonicalUrl":"https://jobsearcher.com/jobs/aec4a528ee37df2ccd46da36","title":"Founding Engineer","description":"About The RoleThis is a security-focused product handling real money, and Sebastian currently owns everything from smart contracts and backend to app, infra, and security/audits; you'll be taking meaningful chunks of that off his plate.Very open to different combinations. Full-stack is an easy win right now. A super focused backend engineer with littleproduct experience would also be a big win. \"Happy to pitch in on product and UI\" is also a plus, but not a requirement.In order of priority:Security expert with some experience in smart contracts would be the top, although there is a higher bar for this (and more equity on the table) and it is not the initial focus of my recruiting search as I'm complementing this with external security firms in the short term while I build leverage to go hire this personFull StackBackendProduct/FrontendNot really looking for infra/devops at this time. Hoping to find a security person who is proficient at this later.Key ResponsibilitiesBackend & integrationsDesign and build backend services that connect custody, fiat rails, policies, and operational workflows.Implement and maintain APIs and services that power ACH, wires, cards, permissions, AML/compliance workflows, and reporting.Smart contracts & security-sensitive logicImplement and review Solidity smart contracts, focusing on correctness, safety, and upgradeability.Contribute to threat modeling, security reviews, and audit/vendor management under Sebastian's supervision.Product & full-stack workCollaborate on the design and implementation of customer-facing applications (currently Dart/Flutter on the client).Help translate user and operational needs into product and UX decisions, especially around permissions, approvals, and money flows.Security & audit participationOwn parts of the audit/security review process for your areas of the stack, coordinating with external security firms.Build systems and internal processes with a security-first mindset appropriate for handling customer funds.Tech stackReins' current stack includes:Backend: TypeScriptSmart contracts: SolidityClient applications: Dart / FlutterThere are no hard \"must have\" technologies, but experience or strong interest in these areas is helpful.RequirementsRoughly 3-6 years of professional experience, with openness to high-potential 0-3 years if there is strongevidence of capability and ownership.Prior early-stage startup experience or very strong ownership in a small team (especially in fintech or infrastructure)Solid backend engineering skills, comfortable designing and implementing production services and integrations.Bonus Skills Experience in fintech (payments, neobanks, custody, treasury, cards) is even more valuable than pure crypto experience. Prior work with Solidity or other smart contract languages, ideally combined with backend experience. Full-stack capabilities (comfortable jumping into frontend/product/UI in addition to backend and contracts). Experience with audits, security reviews, threat modeling, or working closely with external security vendors. Crypto/web3 familiarity or curiosity; prior stablecoin or DeFi experience is a plus but not required. Smart contracts guy who is good at backend + a product engineer that is full-stack and can also touch the backend is the ideal configuration","company":"Techchain Talent","rawCompany":"techchain talent","city":"Millbrae","state":"CA","isRemote":false,"isActive":false,"createdAt":"2026-04-09T11:19:04.701Z","occupations":[{"code":"15-1252.00","title":"Software Developers","slug":"software-developers"},{"code":"15-1299.07","title":"Blockchain Engineers","slug":"blockchain-engineers"},{"code":"15-1299.08","title":"Computer Systems Engineers/Architects","slug":"computer-systems-engineers-architects"}],"industries":[{"code":"513210","title":"Software Publishers","slug":"software-publishers"},{"code":"541511","title":"Custom Computer Programming Services","slug":"custom-computer-programming-services"},{"code":"541512","title":"Computer Systems Design Services","slug":"computer-systems-design-services"}],"jobPosting":{"@context":"https://schema.org","@type":"JobPosting","title":"Founding Engineer","description":"About The RoleThis is a security-focused product handling real money, and Sebastian currently owns everything from smart contracts and backend to app, infra, and security/audits; you'll be taking meaningful chunks of that off his plate.Very open to different combinations. Full-stack is an easy win right now. A super focused backend engineer with littleproduct experience would also be a big win. \"Happy to pitch in on product and UI\" is also a plus, but not a requirement.In order of priority:Security expert with some experience in smart contracts would be the top, although there is a higher bar for this (and more equity on the table) and it is not the initial focus of my recruiting search as I'm complementing this with external security firms in the short term while I build leverage to go hire this personFull StackBackendProduct/FrontendNot really looking for infra/devops at this time. Hoping to find a security person who is proficient at this later.Key ResponsibilitiesBackend & integrationsDesign and build backend services that connect custody, fiat rails, policies, and operational workflows.Implement and maintain APIs and services that power ACH, wires, cards, permissions, AML/compliance workflows, and reporting.Smart contracts & security-sensitive logicImplement and review Solidity smart contracts, focusing on correctness, safety, and upgradeability.Contribute to threat modeling, security reviews, and audit/vendor management under Sebastian's supervision.Product & full-stack workCollaborate on the design and implementation of customer-facing applications (currently Dart/Flutter on the client).Help translate user and operational needs into product and UX decisions, especially around permissions, approvals, and money flows.Security & audit participationOwn parts of the audit/security review process for your areas of the stack, coordinating with external security firms.Build systems and internal processes with a security-first mindset appropriate for handling customer funds.Tech stackReins' current stack includes:Backend: TypeScriptSmart contracts: SolidityClient applications: Dart / FlutterThere are no hard \"must have\" technologies, but experience or strong interest in these areas is helpful.RequirementsRoughly 3-6 years of professional experience, with openness to high-potential 0-3 years if there is strongevidence of capability and ownership.Prior early-stage startup experience or very strong ownership in a small team (especially in fintech or infrastructure)Solid backend engineering skills, comfortable designing and implementing production services and integrations.Bonus Skills Experience in fintech (payments, neobanks, custody, treasury, cards) is even more valuable than pure crypto experience. Prior work with Solidity or other smart contract languages, ideally combined with backend experience. Full-stack capabilities (comfortable jumping into frontend/product/UI in addition to backend and contracts). Experience with audits, security reviews, threat modeling, or working closely with external security vendors. Crypto/web3 familiarity or curiosity; prior stablecoin or DeFi experience is a plus but not required. Smart contracts guy who is good at backend + a product engineer that is full-stack and can also touch the backend is the ideal configuration","datePosted":"2026-04-09T11:19:04.701Z","dateModified":"2026-04-09T11:19:04.701Z","hiringOrganization":{"@type":"Organization","name":"Techchain Talent","sameAs":"https://jobsearcher.com"},"jobLocation":{"@type":"Place","address":{"@type":"PostalAddress","addressLocality":"Millbrae","addressRegion":"CA","addressCountry":"US"}},"identifier":{"@type":"PropertyValue","name":"JobSearcher","value":"aec4a528ee37df2ccd46da36"},"url":"https://jobsearcher.com/jobs/aec4a528ee37df2ccd46da36"}}