Security Engineer

We are building a modern hotel booking platform enhanced with Web3 capabilities, includingtoken-based payments, on-chain verification, and decentralized identity/ownership features.We’re looking for a Backend Engineer to design and build scalable backend systems andintegrate them with blockchain infrastructure. You’ll work closely with frontend and Web3engineers to deliver a seamless and reliable platform. 

Merklio is expanding its cross-chain orchestration layer. We are building a sovereign app-chain (Rollup-style) that aggregates liquidity from multiple L1s via IBC. We need a Blockchain Engineer to design, implement, and maintain our Cosmos-based chain.
Expectations:
Design custom modules (x/staking, x/rewards, x/merkl)
Implement IBC light clients and relayers
Optimize block time and state pruning
Write comprehensive unit & integration tests (Go test)
Build CLI tools for validators and delegators
Monitor node health and network upgrades
Collaborate with the research team on MEV-resistant ordering
Maintain chain upgrades (v1 → v2) with migration scripts
Write technical documentation for external validators
Nice to have:
Experience with Avalanche Subnets or Polkadot Substrate
Knowledge of HSM and key management
Open-source contributions to Cosmos SDK or related repos
Chinese+English language proficiency

Worklo is building the future of professional services automation by combining our core PSA platform with a blockchain-powered salary distribution system. The platform automates compensation based on project data, time entries, role assignments, milestones, and secure on-chain payroll execution.
We are looking for a highly capable Full Stack / Blockchain Engineer who can own both SaaS product development and blockchain infrastructure. This is a high-ownership role where you will help shape Worklo PSA and our blockchain payroll architecture from the ground up.
Key Responsibilities
* Build full-stack product features using Next.js, TypeScript, Node.js/Express, Supabase, PostgreSQL, React, shadcn/ui, and Tailwind CSS
* Design secure APIs, database schemas, authentication flows, and Supabase RLS policies
* Develop Solidity smart contracts for salary calculation and automated payroll distribution
* Build blockchain integrations for wallet registry, MetaMask/WalletConnect, payroll execution, and event syncing
* Deploy and manage smart contracts on Polygon or other EVM-compatible networks
* Implement dashboards for payroll visibility, wallet management, and transaction history
* Write tests for smart contracts using Hardhat, Foundry, or similar tools
* Improve performance, security, observability, and overall system architecture
Requirements
* 5+ years of full-stack software development experience
* 5+ years of blockchain development experience with deployed smart contracts
* Strong skills in TypeScript, Node.js, React, Next.js, PostgreSQL, and REST APIs
* Strong Solidity knowledge, including access control, reentrancy protection, gas optimization, and upgradeability
* Experience with ethers.js, viem, ERC-20 tokens, stablecoins, and EVM-compatible networks
* Ability to work independently in a remote-first, async startup environment
Nice to Have
* Experience with Supabase, Next.js App Router, React Server Components, Foundry, Hardhat, OpenZeppelin, The Graph, DeFi systems, multi-sig wallets, or multi-tenant SaaS platforms

I am looking for a developer who has much experience in Mobile application development.
But specially, candidate should be native in English.
Team communication is very important.
Please bid US only
Thank you

Hi,
I need a custom ebay like site for bitcoins or using stock credit on it. I need it to let you pay the user verbally, like an agreement you agree on that's it. I need the site fixed so it can be upgraded in the future.
I need it to be fixed so you can upload something to the site and sell it.
All I ask is keep the buying and selling part verbal agreements only. Like sending the user stock credit virtually.
Bid on things on the website 
Sell things on the website
Buy things on the website
All I ask is keep the programming simple and the website in a simple form.
I need a website for the web browser and one for the phone web browsers.
If you can put in a custom user admin for it also, then that will be great.
Thank you,
Chris Clark (666 Encryption, CEO)