Senior Software Engineer, Backend

Status
Full time
Remote
Compensation is not specified
Role
Software Engineer
Description

Circle is a fintech company that operates in the realm of digital currency and blockchain technology. We are at the forefront of the emerging internet of money, enabling value to be exchanged digitally on a global scale, swiftly and cost-effectively. Our innovative infrastructure, including the blockchain-based dollar called USDC, empowers businesses, institutions, and developers to leverage the possibilities presented by this digital ecosystem.

What We Offer:

At Circle, we prioritize transparency and stability in our operations. As we expand our presence across various jurisdictions, we aim for agility and effectiveness in everything we do. Our employees embody our core company values of being Multistakeholder, Mindful, Driven by Excellence, and High Integrity. In a remote work environment, we thrive on collaboration, with each individual making a meaningful contribution to our collective success. Our work culture encourages fresh ideas and ensures that everyone has a stake in our organization.

Role Overview:

We are currently seeking a highly skilled and experienced Senior Backend Engineer to join our dynamic team at Circle. As a Senior Backend Engineer, you will play a key role in designing and developing various services on our wallet infrastructure while maintaining the underlying code.

Your Responsibilities:

In this role, your main tasks will include:

  • Analyzing data, processes, and codes to identify areas for improvement and develop effective solutions
  • Creating services, APIs, and SDKs that align with data protection standards and facilitate the implementation of protection controls for other developers
  • Collaborating with front-end developers and other team members to establish objectives and enhance the functionality and coherence of the codebase
  • Involvement in the entire application lifecycle
  • Building reusable code of high quality for future use
  • Conducting whitebox tests and optimizing performance
  • Actively participating in conferences and educational programs
  • Keeping up to date with new and emerging technologies and providing training and support to team members
  • Taking on project leadership as required

Our Core Values:

In everything you do at Circle, you will embody our four core values:

  • Multistakeholder: Demonstrating dedication and commitment to our customers, shareholders, employees, families, and local communities
  • Mindful: Displaying respect, active listening, and attention to detail
  • Driven by Excellence: Relentlessly pursuing excellence, rejecting mediocrity, and working intensively to achieve goals and ensure customer success
  • High Integrity: Valuing open and honest communication, holding yourself to high moral and ethical standards, and rejecting manipulation, dishonesty, and intolerance

Qualifications:

To thrive in this role, you should possess the following qualifications and skills:

  • Minimum of 4 years of professional software development experience, working with object-oriented languages such as Java and Go
  • Bachelor's degree or equivalent experience in Computer Science or a closely related field
  • Familiarity with Golang Web Frameworks like Gin and Fasthttp, and knowledge of Golang development tools like go mod and go lint
  • Experience with database operations, including MySQL, PostgreSQL, and NoSQL, and proficiency in operating databases through raw commands
  • Knowledge and experience in unit test development, with a focus on producing high-quality code
  • Strong understanding of microservices development cycle, programming techniques, and tools
  • Familiarity with cryptography is a plus
  • Excellent project and time management skills
  • Strong communication skills, with the ability to collaborate effectively with remote teams, share ideas, and present concepts
  • Self-starter mentality, thriving in a fast-paced environment and able to independently ship software that improves user experience while constantly improving your own work
  • Past experience leading technically on architecture and system design for teams of 2-4 members

Circle is proud to be an equal opportunity employer that values diversity. We do not discriminate on the basis of race, religion, color, national origin, gender, sexual orientation, age, marital status, veteran status, or disability status. In certain locations, Circle participates in the E-Verify Program as required by law.

Skills Required
Avatar
Circle
Company size
Not specified
Location
United States
Description
Not specified
Status

More Full-time Jobs

Show more

Senior Go Developer

Full time
Remote
Senior Go Developer (Crypto focus; remote) The company (name withheld till the interview stage) is a non-custodial staking, re-staking, and node hosting platform that delivers advanced, secure infrastructure for institutional and retail investors. With automated services and an intuitive interface, we simplify the process of running full nodes, masternodes, and validators across 77 Proof-of-Stake blockchain protocols, hosting tens of thousands of nodes globally.In addition, we contribute to the blockchain ecosystem by offering complimentary tools and RPC endpoints for over 100 blockchain protocols, enabling users and developers to engage with their preferred blockchain networks and build innovative solutions!We are seeking a strong Senior Go Developer with experience in cryptocurrency. Requirements:Cryptocurrency and Node Experience: Minimum 1.5–2 years of experience working in the cryptocurrency space, specifically with nodes.Extensive experience and expertise in Go development.Russian or Ukrainian language proficiency.Knowledge of Node.js is a plus.Experience working in a remote, asynchronous environment.Familiarity with Slack for communication and collaboration.Working hours:You may start your 8-hour working day between 7 and 11 am GMT+3. For example, from 9 am to 5 pm GMT+3, etc.Remote team spanning from Los Angeles to London to Dubai, with minimal calls and Slack-based communication & decision-making.The team consists of 6-10 members with a strong sense of commitment—many have been with us for over 7 years. What we offer:Full-time job (8 working hours per day, Monday-Friday).Remote work. You may be located in any country, just need a good Internet connection, a powerful computer to work from, and the opportunity to adjust your working schedule for the team.Be part of a fast-growing, highly respected company in the crypto industry.Stability. This is not project work, we consider only the candidates looking for a long-term commitment of 1.5+ years.Work autonomously with a team of like-minded professionals.Engage in challenging and innovative projects with cutting-edge blockchain technologies.Salary will be discussed during the interview. Paid in USDT. Application deadline: ASAPSelection process:1. Fill in the application form - attach your CV & a GitHub portfolio link;2. Have a Zoom interview with Hire5 Recruiter;3. Have a technical Zoom meeting with the developer from the company team;4. Have a quick Zoom interview with the CEO of the company;5. Get hired!
Payment in Crypto
5,000-9,000
Monthly
See details

Web3 + Supabase Developer Needed to Complete BSC Testnet Waitlist & Staking Platform

Washington, USA
Washington, USA
Part time
Remote
📌 Job Description
 
We are building a production-ready Web3 waitlist and dashboard platform using Next.js 15 (App Router), BSC Testnet, Supabase, and Wagmi v2.
The core architecture, database schema, and feature roadmap are already defined. We are looking for an experienced developer to complete, polish, and harden the project.
 
This is not a prototype — the goal is a fully working, deployable system with clean code, security best practices, and proper Web3 UX.
 
🧩 Project Overview
 
The platform includes:
Wallet-based user registration (BSC Testnet only)
Automatic network detection & switching
Supabase-backed user management
Automatic virtual card generation (Bronze / Silver / Gold)
Token staking system with transaction logging
Referral system with rewards tracking
Dashboard with analytics & history
X (Twitter) OAuth integration
Discord bot with XP & invite tracking
A detailed README and database schema are already prepared.
 
✅ Responsibilities
 
You will be responsible for:
 
Completing and stabilizing the Next.js App Router implementation
Finalizing wallet connection & network enforcement (Chain ID 97)
Ensuring Supabase RLS policies are correct and secure
Implementing or completing:
Staking flows (stake, unstake, claim, emergency withdraw)
Referral tracking & reward logic
Dashboard analytics & transaction history
Finalizing X (Twitter) OAuth integration
Reviewing and improving overall code quality & structure
Fixing bugs, edge cases, and UX issues
Preparing the app for Railway deployment
(Bonus) Improving performance and Web3 UX
 
🛠 Tech Stack (Must-Have Experience)
 
Required:
 
Next.js 14/15 (App Router)
TypeScript
Wagmi v2 + WalletConnect
EVM chains (BSC preferred)
Supabase (Postgres, RLS, triggers, SQL functions)
Tailwind CSS
Web3 transaction handling & logging
 
Nice to Have:
 
Discord bot development (Node.js)
OAuth 2.0 (X / Twitter)
Smart contract interaction (staking contracts)
Framer Motion
shadcn/ui / Radix UI
 
🔒 Security Expectations
 
You must be comfortable with:
Wallet validation & chain enforcement
Preventing self-referrals & abuse
Transaction hash uniqueness checks
Secure handling of OAuth tokens
Supabase RLS & role-based access
 
📦 Deliverables
 
Fully working, deployable application
Clean, documented codebase
Verified Supabase schema & policies
Functional staking & referral systems
Deployment-ready build (Railway)
Basic handover documentation
 
⏳ Timeline
 
Estimated duration: 2–4 months
Start: Immediately
Potential for long-term collaboration
 
💰 Budget
 
Open to fixed-price or hourly
Please include:
 
Your estimated timeline
Relevant Web3 / Next.js projects
Any questions or suggestions to improve the system
 
🧠 How to Apply
 
When applying, please answer:
 
Have you built production Web3 apps with Next.js + Wagmi before?
Have you worked with Supabase RLS & SQL triggers?
Share 1–3 relevant projects (GitHub or live links)
What risks or improvements do you see in this architecture?
Generic proposals will be ignored.
Payment in Crypto
4,500
Monthly
See details

Senior Web3 / Crypto Trading Platform Developer

Full time
Remote
PumaPulse is launching a new standalone domain focused on building professional-grade crypto trading platforms and on-chain trading tools. We are seeking an experienced freelance Web3 developer to help design, build, and evolve a scalable trading product with commercialization potential.ResponsibilitiesDevelop crypto trading tools, bots, or SaaS platformsIntegrate with DEXs and on-chain protocols (e.g., Solana, Ethereum)Implement real-time blockchain data monitoring and trade executionEnsure security, performance, and MEV-aware designCollaborate on product roadmap, strategy, and future featuresRequirementsStrong experience in Web3 and DeFi developmentProven work with crypto trading bots or on-chain trading systemsExperience with at least one major blockchain ecosystemSolid understanding of smart contract interaction and security best practicesAbility to deliver production-ready code and communicate clearlyNice to HaveExperience productizing tools into SaaS platformsBackground in advanced trading strategies or MEVPrior work with VC-backed or early-stage Web3 projectsEngagementFreelance / contract roleCompetitive compensation based on experiencePotential for long-term collaborationApply with relevant Web3 projects, GitHub links, and availability.
Payment in Crypto
50-80
Monthly
See details

Fullstack Developer Needed for Web3 Prediction Market Platform

Brooklyn, USA
Brooklyn, USA
Full time
Remote
Summary
We're looking for an experienced Blockchain / Full-Stack Developer to help build a production-ready MVP for a Web3 prediction marketplace.
We’ve already built a basic UI prototype using vibe coding. The goal now is to turn this prototype into a functional, scalable dApp with clean architecture and solid Web3 fundamentals.
This is not a tutorial or experimental project — We’re looking for someone who has real experience shipping blockchain/web3 products.
What You’ll Do
Review and improve an existing UI prototype
Build smart contract logic for a prediction marketplace MVP
Integrate blockchain functionality with the frontend
Develop backend / API logic as needed
Ensure clean, maintainable, production-ready code
Collaborate on product decisions and MVP scope
Tech Stack (Preferred)
Frontend: Next.js / React
Backend: Node.js
Blockchain: Solidity / Rust
Experience with non-EVM chains is a plus (open to discussion)
What We're Looking For
- Strong experience in Blockchain & Web3 development
- Proven ability to build production-ready dApps
- Proficiency in Next.js, React, and Node.js
- Experience designing and shipping MVPs
- Good communication and ability to work independently
Nice to Have
- Previous work on prediction markets, DeFi, or marketplaces
- Experience taking projects from prototype to launch
- Performance, security, and scalability mindset
How to Apply
Please include:
- A brief summary of your Web3 experience
- Links to previous dApps or blockchain projects
- Your preferred tech stack and availability
If you’re an expert in blockchain and Web3 and enjoy building real products from early prototypes, We’d love to hear from you.
Payment in Crypto
8,000-9,000
Monthly
See details

Looking for a blockchain developer

Whiteman Air Force Base, USA
Whiteman Air Force Base, USA
Full time
Remote
We are looking for a skilled Full-Stack Blockchain Developer to help maintain, improve, and extend the RaiseHive platform. This role involves working across the frontend, backend, and smart contract layers to ensure a stable, secure, and scalable Web3 application.
The ideal candidate has hands-on experience with React, Node.js, Ethereum smart contracts, and real-world Web3 integrations.
Framework: React 18.2 (Vite 3)
Styling: Tailwind CSS 3.4, NextUI
Animations: Framer Motion
Web3: Thirdweb SDK v4, Ethers.js v5
Routing: React Router DOM v6
State Management: React Context API
Libraries: React Markdown, React Image Gallery, Replyke (comments), React Toastify
Runtime: Node.js
Framework: Express.js
Database: MongoDB Atlas (Mongoose ODM)
Email: Nodemailer
Scheduling: Node-cron
Logging: Pino
Network: Ethereum
Smart Contracts: Solidity ^0.8.19
Development Tools: Hardhat
Libraries: OpenZeppelin, Thirdweb Contracts
Wallet Integration: MetaMask
Frontend
Strong proficiency in React (hooks, context, routing)
Experience with Vite or modern build tools
Solid knowledge of Tailwind CSS and responsive design
Experience using component libraries (NextUI, Material UI, etc.)
Backend
Strong experience with Node.js and Express
Proficiency with MongoDB and Mongoose
REST API design and implementation
Environment configuration and deployment awareness
Blockchain & Web3
Hands-on Ethereum development experience
Solidity smart contract development
Experience with Ethers.js / Thirdweb SDK
Understanding of smart contract security and gas optimization
MetaMask wallet integration and transaction handling
General
JavaScript (ES6+)
Git version control
Async programming and debugging skills
Strong problem-solving ability
Payment in Crypto
125
Monthly
See details