Senior Engineer - Platform Risk(Java)
Hong Kong
Full time
Office
Compensation is not specified
Role
Backend Engineer
Description
Who We Are
At OKX, we believe that technology is reshaping our future. Founded in 2017, OKX is a leading cryptocurrency spot and derivatives exchange that has embraced blockchain technology. We offer a wide range of diverse and advanced products, solutions, and trading tools in the financial ecosystem. With over 20 million users in 180 regions, our goal is to provide a platform that empowers individuals to explore the world of crypto. In addition to our exchange, we have OKX Insights, a research arm focused on the latest trends in the cryptocurrency industry. Our vision is to create a world of financial access backed by blockchain and decentralized finance.
We value our people as much as technology. Our culture promotes teamwork, embraces change, and fosters a friendly and diverse environment for our employees. We believe in creating equal opportunities for everyone to develop and thrive.
About the Platform Tool Team
The Platform Tool team is responsible for providing infrastructure support to different teams within OKX. This includes message delivery abilities such as email, push notifications, and SMS, as well as managing the notification center and verification codes. Our aim is to help the tech teams streamline their work and improve their development efficiency.
What You’ll Be Doing:
- Coordinating the backend requirements, technical design, and development of the message delivery business.
- Optimizing system performance, solving technical problems, and ensuring high availability, reliability, and performance.
- Driving workflow optimization, improving cross-team communication, and enhancing team collaboration.
- Leading the team in technology reserves, taking on team responsibilities, and nurturing technical talent.
What We Look For In You:
- Strong foundation in Java, with a deep understanding of JVM configuration optimization, IO, multi-threading, concurrent frameworks, data structures, algorithms, and design patterns. Demonstrating good programming practices and substantial work experience.
- Familiarity with common middleware such as MQ, RPC, caching, message queues, and MySQL.
- In-depth understanding of distributed system principles, including CAP theorem, consistency, and idempotent operations.
- Clear logical thinking, agile mindset, and excellent communication skills.
- Strong team management and architectural design capabilities, with preference for those with team management experience.
- Preferred experience in integrating and developing platforms for email, SMS, push notifications, etc.
Perks & Benefits
- Competitive total compensation
- Comprehensive insurance coverage for employees and dependants
- More benefits to be communicated during the hiring process!
Skills Required
OKX
Website
www.okx.comCompany size
Not specified
Location
United States
Description
Not specified
Ment Tech
Senior Software Engineer (Blockchain)
Mumbai, India +3
Mumbai, India +3
Full time
Remote
About MentTech
MentTech is a forward-thinking technology company dedicated to transforming how mentoring and learning are delivered in the digital age. By combining advanced tools, intelligent systems, and a human-first approach, MentTech helps individuals, teams, and organizations harness the power of mentorship to unlock potential, build skills, and achieve lasting growth.
The Role
We are seeking a Smart Contract Developer responsible for ensuring that game listings within MentTech work properly and ensuring compliance with all game store policies.
Key Responsibilities:
• Architect, implement, and deploy secure smart contracts for an on-chain Play-to-Earn GameFi ecosystem
• Lead contract design decisions with a focus on robustness, auditability, gas efficiency, and resilience to attack vectors
• Mentor/junior developers: perform code reviews, establish standards, best practices in security & testing
• Collaborate cross-functionally with game designers, backend, QA, and security teams to align smart contract features with product roadmap
Qualifications:
• 2+ years hands‐on experience developing & deploying smart contracts (Solidity / EVM or equivalent) in production environments
• Track record of writing secure contracts, familiarity with common vulnerabilities (reentrancy, integer over/underflow, front-running, flash loans, etc.)
• Experience with audits, formal verification, fuzz testing, or other advanced contract assurance methods
• Strong test suite / CI workflow skills; comfortable using tools like Hardhat, Foundry, Truffle etc.
• Solid understanding of GameFi mechanics and how on-chain economics work
Bonus Points:
• Experience on multiple EVM chains or Layer-2 / sidechains
• Knowledge of cross-chain bridges, oracles, NFTs, tokenomics design
• Contributions to open-source security tooling or prior audit reports or published code you’re proud of
Why join MentTech?
At MentTech, we cultivate a culture of flexibility, autonomy, and the freedom to make a real impact on the broader Web3 ecosystem. Experience the advantages of a fully remote working environment where your expertise and contributions are rewarded with competitive compensation tailored to your role and project influence.
Ment Tech Labs
• Employee Equity & Incentives: Unlock future growth with equity and other potential incentives.
• Entrepreneurial Culture: Join a collaborative environment where we innovate together as partners.
• Cutting-edge Innovation: Work at the forefront of gaming and blockchain.
• Key Strategic Projects: Be part of transformative initiatives that are redefining the gaming landscape.
• Remote Flexibility: Enjoy a truly flexible, fully remote work setup that supports your lifestyle.
• Talented Team: Collaborate with a team of passionate, driven, and skilled professionals.
• Community Impact: Contribute to the growth and success of the Web3 and gaming communities.
• Flexible Payment Options: Receive payments in crypto or fiat, tailored to your preference.
• Growth Opportunities: Access valuable learning experiences and development paths.
MentTech Labs, Inc. is an equal opportunities workplace that doesn’t discriminate based on race, ethnicity, gender, ancestry, national origin, religion, sex, sexual orientation, gender identity, age disability, veteran status, genetic information, marital status, or any other legally protected status.
MentTech is a forward-thinking technology company dedicated to transforming how mentoring and learning are delivered in the digital age. By combining advanced tools, intelligent systems, and a human-first approach, MentTech helps individuals, teams, and organizations harness the power of mentorship to unlock potential, build skills, and achieve lasting growth.
The Role
We are seeking a Smart Contract Developer responsible for ensuring that game listings within MentTech work properly and ensuring compliance with all game store policies.
Key Responsibilities:
• Architect, implement, and deploy secure smart contracts for an on-chain Play-to-Earn GameFi ecosystem
• Lead contract design decisions with a focus on robustness, auditability, gas efficiency, and resilience to attack vectors
• Mentor/junior developers: perform code reviews, establish standards, best practices in security & testing
• Collaborate cross-functionally with game designers, backend, QA, and security teams to align smart contract features with product roadmap
Qualifications:
• 2+ years hands‐on experience developing & deploying smart contracts (Solidity / EVM or equivalent) in production environments
• Track record of writing secure contracts, familiarity with common vulnerabilities (reentrancy, integer over/underflow, front-running, flash loans, etc.)
• Experience with audits, formal verification, fuzz testing, or other advanced contract assurance methods
• Strong test suite / CI workflow skills; comfortable using tools like Hardhat, Foundry, Truffle etc.
• Solid understanding of GameFi mechanics and how on-chain economics work
Bonus Points:
• Experience on multiple EVM chains or Layer-2 / sidechains
• Knowledge of cross-chain bridges, oracles, NFTs, tokenomics design
• Contributions to open-source security tooling or prior audit reports or published code you’re proud of
Why join MentTech?
At MentTech, we cultivate a culture of flexibility, autonomy, and the freedom to make a real impact on the broader Web3 ecosystem. Experience the advantages of a fully remote working environment where your expertise and contributions are rewarded with competitive compensation tailored to your role and project influence.
Ment Tech Labs
• Employee Equity & Incentives: Unlock future growth with equity and other potential incentives.
• Entrepreneurial Culture: Join a collaborative environment where we innovate together as partners.
• Cutting-edge Innovation: Work at the forefront of gaming and blockchain.
• Key Strategic Projects: Be part of transformative initiatives that are redefining the gaming landscape.
• Remote Flexibility: Enjoy a truly flexible, fully remote work setup that supports your lifestyle.
• Talented Team: Collaborate with a team of passionate, driven, and skilled professionals.
• Community Impact: Contribute to the growth and success of the Web3 and gaming communities.
• Flexible Payment Options: Receive payments in crypto or fiat, tailored to your preference.
• Growth Opportunities: Access valuable learning experiences and development paths.
MentTech Labs, Inc. is an equal opportunities workplace that doesn’t discriminate based on race, ethnicity, gender, ancestry, national origin, religion, sex, sexual orientation, gender identity, age disability, veteran status, genetic information, marital status, or any other legally protected status.
Payment in Crypto
Sirex
Product Manager – Portfolio Companies
Full time
Remote
Product Manager – Portfolio Companies
Sirex Portfolio Companies
Salary: $135,000 – $190,000 USD base + equity
Location: Remote-first
About the role Own product strategy and roadmap for 1–2 portfolio projects (DeFi protocols, trading platforms or RWA infrastructure).
What you’ll do
Define vision, prioritize features and write specs
Work directly with smart-contract and frontend teams
Design user flows and drive product-market fit
Run user research and iterate fast
Requirements
4+ years Product Management experience
Previous Web3/DeFi product experience mandatory
Strong technical intuition
Apply → Send CV + 1 strongest product case
Sirex Portfolio Companies
Salary: $135,000 – $190,000 USD base + equity
Location: Remote-first
About the role Own product strategy and roadmap for 1–2 portfolio projects (DeFi protocols, trading platforms or RWA infrastructure).
What you’ll do
Define vision, prioritize features and write specs
Work directly with smart-contract and frontend teams
Design user flows and drive product-market fit
Run user research and iterate fast
Requirements
4+ years Product Management experience
Previous Web3/DeFi product experience mandatory
Strong technical intuition
Apply → Send CV + 1 strongest product case
Payment in Crypto
Sirex
Frontend Engineer – Web3 Products
Full time
Remote
Frontend Engineer – Web3 Products
Sirex Portfolio Companies
Salary: $120,000 – $175,000 USD base + equity
Location: Remote-first
About the role Build beautiful, high-performance frontends for DeFi, RWA and agent platforms (Next.js + Wagmi/Viem stack).
What you’ll do
Ship trading interfaces, dashboards and wallet flows
Optimize for mobile and lightning-fast UX
Integrate with smart contracts and oracles
Work directly with design and product teams
Requirements
3+ years Next.js / React + TypeScript
Strong experience with Wagmi, Viem, RainbowKit or similar
Web3 product intuition (wallets, transactions, gas UX)
Apply → Send CV + GitHub
Sirex Portfolio Companies
Salary: $120,000 – $175,000 USD base + equity
Location: Remote-first
About the role Build beautiful, high-performance frontends for DeFi, RWA and agent platforms (Next.js + Wagmi/Viem stack).
What you’ll do
Ship trading interfaces, dashboards and wallet flows
Optimize for mobile and lightning-fast UX
Integrate with smart contracts and oracles
Work directly with design and product teams
Requirements
3+ years Next.js / React + TypeScript
Strong experience with Wagmi, Viem, RainbowKit or similar
Web3 product intuition (wallets, transactions, gas UX)
Apply → Send CV + GitHub
Payment in Crypto
Sirex
On-Chain Data Analyst
Full time
Remote
On-Chain Data Analyst
Sirex Fund + Portfolio
Salary: $110,000 – $160,000 USD base + equity
Location: Remote-first
About the role
Turn raw blockchain data into actionable investment insights and portfolio monitoring tools.
What you’ll do
Build and maintain Dune dashboards + custom indexers
Track TVL, user activity, token flows and protocol health
Create weekly investment memos and anomaly alerts
Support due diligence with on-chain forensics
Requirements
Strong SQL + Python experience
Deep knowledge of The Graph, Dune, Flipside or custom subgraphs
Previous crypto research or trading background
Apply → Send CV + 1 example Dune dashboard
Sirex Fund + Portfolio
Salary: $110,000 – $160,000 USD base + equity
Location: Remote-first
About the role
Turn raw blockchain data into actionable investment insights and portfolio monitoring tools.
What you’ll do
Build and maintain Dune dashboards + custom indexers
Track TVL, user activity, token flows and protocol health
Create weekly investment memos and anomaly alerts
Support due diligence with on-chain forensics
Requirements
Strong SQL + Python experience
Deep knowledge of The Graph, Dune, Flipside or custom subgraphs
Previous crypto research or trading background
Apply → Send CV + 1 example Dune dashboard
Payment in Crypto
Sirex
Operations Associate / Chief of Staff
Full time
Remote
Operations Associate / Chief of Staff
Sirex Fund Salary: $95,000 – $135,000 USD base + carry Location: Remote-first
About the role Be the right-hand person to partners: run fund operations, portfolio support and internal processes.
What you’ll do
Manage deal flow, data rooms and investment memos
Coordinate portfolio reporting and founder updates
Handle legal, compliance and admin tasks
Support events, LP communication and hiring
Requirements
2–4 years in VC, startup ops or consulting
Extremely organized and fast-moving
Web3/native crypto understanding is mandatory
Apply → Send CV + short note “Why you’d be a great CoS”
Sirex Fund Salary: $95,000 – $135,000 USD base + carry Location: Remote-first
About the role Be the right-hand person to partners: run fund operations, portfolio support and internal processes.
What you’ll do
Manage deal flow, data rooms and investment memos
Coordinate portfolio reporting and founder updates
Handle legal, compliance and admin tasks
Support events, LP communication and hiring
Requirements
2–4 years in VC, startup ops or consulting
Extremely organized and fast-moving
Web3/native crypto understanding is mandatory
Apply → Send CV + short note “Why you’d be a great CoS”
Payment in Crypto