Frontend Engineer (React, Web3)

Saifuro

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Location: Worldwide
Job Type: full-time
Work Format: 🌍 Remote Worldwide
Salary: $155,000 to $190,000
Posted: October 22, 2026

Job Description

Saifuro checks payments that AI agents try to make. An agent asks to spend, we compare the request with a mandate a human approved earlier, and the answer comes back signed so the receiving side can verify it. There's escrow on Base and Solana for trades between agents, and settlement is in USDC, onchain. We never hold customer funds. The docs are public at docs.saifuro.com, and the people who use them are developers building agents and the teams selling APIs to those agents.

Saifuro's console is where a finance team keeps watch over its agents' spending and approves the payments that need a person. Others on the team build the API behind it, so your time goes into the screens. You may also know the role as React developer, UI engineer or Web3 frontend developer. It's React and TypeScript, and you work directly with our CTO.

What you'd be doing

The console. Build the screens a finance team opens every day: what each agent spent, the decision behind every payment, and the queue of payments waiting for approval.
The policy editor. Turn spending rules into something a non-engineer can read, compare and publish, with a change history that shows who changed what.
Onchain. Show USDC payments and escrow on Base and Solana in plain terms, so anyone can follow a payment from approval to its transaction without opening a block explorer.
A self-serve sandbox early next year, so developers can try Saifuro without a sales call, then budget forecasting later in 2027. You'll help design both from the first sketch.

What we need from you

You're a frontend engineer who has shipped React and TypeScript in a product people paid for.
You can take a rough idea to a clear, accessible screen without a designer handing you every pixel.
You live in one of the countries we can hire in.

Beyond these requirements, we'll support you in learning whatever else the role demands. If your experience is relevant but your title differs, we would still like to hear from you. Work outside a job counts too: open source, hackathons and your own projects.

It helps, but isn't required, if you've built dashboards for payments or fintech, if you've worked with data-heavy tables and charts, if you've built or maintained a design system, if you're comfortable in Figma, if you've used Next.js and TanStack Query, or if you've built with wagmi, viem, ethers or Solana's web3.js.

Countries we can hire in

The role is fully remote. You can live and work in any of the countries below.

Americas. Argentina, the Bahamas, Brazil, Canada, Chile, Colombia, Costa Rica, Dominican Republic, Ecuador, Guatemala, Mexico, Panama, Paraguay, Peru, the United States (including Puerto Rico), Uruguay.
Europe. Albania, Austria, Belgium, Bosnia and Herzegovina, Bulgaria, Croatia, Cyprus, the Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Liechtenstein, Lithuania, Luxembourg, Malta, Monaco, Montenegro, the Netherlands, North Macedonia, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey, the United Kingdom (including Jersey, Guernsey, the Isle of Man, Gibraltar, Bermuda, the Cayman Islands and the British Virgin Islands).
Middle East and Africa. Bahrain, Israel, Kuwait, Mauritius, Oman, Qatar, Saudi Arabia, South Africa, the United Arab Emirates.
Asia-Pacific. Australia, Brunei, China (including Macau), Hong Kong, India, Indonesia, Japan, Malaysia, New Zealand, the Philippines, Singapore, South Korea, Taiwan, Thailand, Vietnam.

Pay and benefits

Salary $155,000 to $190,000. That's the US range. Outside the US we pay in USD, or in USDC if you'd rather, and set the offer against the top of the local market.
Equity: 0.12% of Saifuro, vesting.
Health: 100% of medical, dental and vision premiums for US employees, 75% for dependents. Outside the US, the local plan through our employer of record, or $300 a month toward private cover.
25 days of paid vacation plus your public holidays, and we close between Christmas and New Year.
14 weeks of paid parental leave, for any parent.
A laptop and $1,000 toward your workspace.
$1,500 a year for learning, conferences included. That's on top of the events you'll attend for work: six to eight a year, planned a quarter ahead, on the company.

Hours are flexible. The one thing we ask is to be online from 14:00 to 17:00 UTC, when the team overlaps for calls and quick questions. That's a window, not the working day. The rest of your hours are yours to arrange. A mainnet incident doesn't keep office hours. If that window is the middle of your night, say so and we'll work something out.

You can combine this with a job at another company, as long as the two don't conflict.

How to apply

Email contact@saifuro.com with the subject "Frontend Engineer". Attach your resume and include links to your GitHub and LinkedIn profiles, as well as X or a personal site if you have them. Let us know your country of residence. We'll reply with the next steps.

Before you answer a recruiter

Job scams sometimes copy real companies. We never ask candidates for money, crypto or payment details.

Real mail from us comes only from @saifuro.com addresses, and interviews are run personally by the founders. If someone asks you for money in our name, it is not us. Forward it to contact@saifuro.com.

How our hiring works and how to check that a message is really from us: the hiring safety page.

Send us something you built

A repo, a write-up or a shipped product says more than a resume. Attach it to your application.

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🎯 Who is this job for?

Suitable level: Senior Frontend Engineer, or a strong Middle-level engineer with experience shipping production React and TypeScript products.

Required skills: React, TypeScript, accessible UI development, product-oriented design judgment, and the ability to work independently from rough concepts; experience with fintech dashboards, data-heavy interfaces, design systems, Next.js, TanStack Query, or Web3 tools such as wagmi, viem, ethers, and Solana web3.js is beneficial.

Relevant tasks: Building finance dashboards, policy editors, approval workflows, data tables and charts, transaction and escrow interfaces across Base and Solana, and early-stage self-service or forecasting products.

💬 Potential Interview Questions

How would you structure a React and TypeScript console for displaying agent spending, payment decisions, and pending approvals?

I would separate the application into feature-based modules, use strongly typed domain models, and keep server state distinct from local UI state. Shared components, predictable routing, and reusable table, filter, and approval patterns would make the console scalable and maintainable.

How would you efficiently render a data-heavy payments table with filtering, sorting, and pagination?

I would use server-side filtering, sorting, and pagination through a query layer such as TanStack Query, while debouncing search inputs and caching stable results. For very large datasets, I would add row virtualization and ensure accessible keyboard navigation and semantic table markup.

How would you design a policy editor that allows non-engineers to compare, modify, and publish spending rules?

I would represent policies with a typed, versioned domain model and provide a form-based editor with human-readable summaries, validation, and clear preview states. Publishing should require explicit confirmation and display the resulting version, author, timestamp, and differences from the previous policy.

How would you implement audit history for policy changes?

I would treat each published policy as an immutable version and display structured diffs rather than relying only on raw JSON comparisons. The UI should show who made the change, when it occurred, what changed, and whether the version is currently active.

How would you present Base and Solana USDC payments so users can understand them without opening a block explorer?

I would normalize transaction data from both chains into a shared presentation model containing status, amount, token, sender, recipient, chain, timestamps, and transaction identifiers. The interface should show a plain-language timeline from approval through submission and confirmation, while still providing an optional explorer link for technical users.

What considerations are important when integrating wallet and blockchain libraries such as wagmi, viem, ethers, or Solana web3.js?

I would isolate chain-specific integrations behind typed service interfaces and avoid coupling UI components directly to provider details. The application must handle wallet connection, network mismatches, transaction simulation, pending states, confirmation failures, retries, and inconsistent RPC responses.

How would you securely handle approval actions in a financial console?

Approval actions should be explicit, permission-checked, and protected against accidental duplicate submissions through idempotency keys and disabled pending states. The frontend should never be treated as the security boundary, so authorization, mandate validation, and signing must also be enforced by the backend or protocol.

How would you manage asynchronous API data and optimistic updates in this application?

I would use a server-state library such as TanStack Query for caching, invalidation, retries, and background refetching. I would use optimistic updates only when the operation is safely reversible, and otherwise show a pending state until the server or chain confirms the action.

How would you build an accessible dashboard with dense tables, charts, and approval workflows?

I would use semantic HTML, visible focus states, keyboard-operable controls, meaningful labels, sufficient color contrast, and status text that does not rely on color alone. Charts should include accessible summaries or tabular alternatives, and loading, empty, error, and confirmation states should be communicated clearly to assistive technologies.

How would you approach designing a self-serve developer sandbox and future budget forecasting features?

I would begin by modeling the primary user journeys, permissions, data states, and failure cases before selecting component patterns. The sandbox should clearly separate test data and networks from production, while forecasting should expose assumptions, time ranges, confidence limits, and explainable calculations rather than presenting unexplained predictions.

📋 Job Summary

Saifuro is hiring a Frontend Engineer to build the React and TypeScript console for monitoring AI-agent payments, approving transactions, editing spending policies, and tracking USDC escrow across Base and Solana. You’ll work directly with the CTO on dashboards, accessible data-heavy interfaces, a developer sandbox, and future forecasting tools, with opportunities to use Next.js, TanStack Query, wagmi, viem, ethers, or Solana web3.js. This is a fully remote, full-time role with flexible hours, a $155,000–$190,000 salary, and 0.12% equity. Apply to shape the user experience of an emerging onchain payments platform while working on meaningful products used by developers and finance teams worldwide.