Currently Software Engineer at HTEC
Senior Web3 Fullstack Developer and AI Enthusiast
I am Sebastian Zambrano Arango, I have always been very curious and an enthusiast about technology. That lead me to discover Blockchain on 2021 and since then start learning about how the technology works, and as I loved it's capabilities and functionalities, I decided I will dedicate to it.
With an school background of C language, I started learning Solidity on my own with all the resources that there are out there, completed several courses and realized I needed to learn more than Solidity if I wanted to dedicate to it, it was there when I learned about security and optimization in Solidity and more Languages and tools for being a Web3 Fullstack Developer such as Javascript and React with NextJs. And for testing all what I have learned I am building a protocol on my own which is in it's MVP phase right now.
Lately I have been paying attention to AIs and figuring out how to use them in my daily study and coding sessions to improve my efficiency.
Recently joined HTEC as a Software Engineer — more details on the work coming soon.
Promoted to lead the Web3 surface of the product: project planning, team management and audit assessment became part of the day-to-day.
Owning features end-to-end — from smart contract design to production rollout — while helping the team keep a high bar on code quality and security.
Solidity
AWS
MongoDB
NestJS
Typescript
Javascript
Kotlin
Chai
HTML
CSSThe possibility of learning an growing in this company is something that I will always be grateful for.
Being working with an amazing product focusing on the purpose of the underlaying technology is something that I always desired when getting into Blockchain and EtherMail made me feel like that.
The mixture of the constant practice of Web3 and Web2 technology made all of my knowledge settle and build one that I did not have before.
SolidityAWSMongoDBNestJSTypescriptJavascriptKotlinChaiHTMLCSSWorking with different clients has allowed me to both improve my skills, adapting myself and learning depending on their needs and requirements, and also to improve my communication skills and candidness.
Having worked from building projects from scratch with no team to teach someone how to code his first Smart Contract, leaving all the basis and resources to follow the study, has given me a solid basis to every project.
Solidity
NextJsMongoDBTypescriptJavascriptChaiHTMLCSSBuilt an OpenClaw skill that gives AI agents full visibility into how EtherMail's services run locally and on remote servers via Docker.
Used for automated debugging and operational insight — agents can now reason about the platform's runtime without manual context.
Created, maintained and continuously extended a CRM-like marketing tool end-to-end — a Web3-native dashboard for audience management, segmentation and email campaign orchestration.
Vue, Nuxt and Nest across the stack, processing large data volumes through Redis, MySQL and MongoDB.
Development of FE, BE & EVM Smart Contracts to send ERC20 and ERC721 tokens via email.
Full integration into the platform, allowing campaigns to deliver token rewards directly to inboxes.
Development of the EMT Token together with two strategy contracts: a recurring user pool and an investor cliff vesting contract.
End-to-end test coverage with Chai and audited rollouts to mainnet.
Scalable backend service that decodes EVM transactions on the fly and presents them in a user-friendly way through email.
Built end-to-end across BE and FE to make on-chain activity readable for non-technical users.
Designed and implemented from scratch a backend system to ingest and monitor on-chain Smart Contract events in real time.
Schema design and sustainable-code focus to support long-term observability and analytics.
Many more coming...
SolidityAWSMongoDBNestJSTypescriptJavascriptKotlinChaiHTMLCSSNextJs
C
GraphQLAnthropic's foundational certification for practitioners building production-grade applications with Claude. It tests architectural decision-making and trade-offs across Claude Code, the Claude Agent SDK, the Claude API and the Model Context Protocol (MCP) — from designing agentic loops and tool interfaces to context management and structured outputs.
Oracle Dev Gym course covering the foundations of SQL — querying, joining, filtering, grouping and modifying relational data, plus the basics of schema design. Finished with a 95% grade.
This was the greatest, longest and most advanced course I have done on Solidity so far, this covered every aspect needed to be a Web3Fullstack, from Solidity Syntax to be able to code our own NFT Marketplace and deploy on a website! Also covered important topics as secuity, proxies and governance tokens.
Visit courseThis was the first course that I took from Solidity, it was very clear at explaning each of Solidity's functionalities, and at the end we ended up building several projects to consolidate what we learned.
Visit courseKind of a game, where you have to hack several contracts in order to pass to the next level, some levels simulate hacks that have happen in the Blockchain ecosystem and each of them gives you the opportunity to learn about Smart Contract's functionality, security or optimization.
Visit courseGreat tool to consolidate Solidity's syntax, did it after my first Solidity course and it really help me to gain confidence with the language for being really intereactive as you learn coding a Crypto Zombies game!
Visit courseHelped me get how to build a NextJs app, and to know all the features and advantages that we have when building a project with this amazing framework.
We do this by building a whole website project going through each of the NextJs functionalities and uses.
Visit courseThis course was the one that gave me the confidence with Frontend, being able, after it, to build my own websites and keep learning about UI and UX building own projects and challenges in Frontend Mentor.
Visit courseI had used and learned JavaScript before, but I lacked some knowledge to really understand all what we did with it on some other courses, this made me really understand the Fundamentals to get it and keep improving.
Visit courseFirst course I did when I started my journey for a Web3 Fullstack Dev, it was clear, helped me get and remember how the logic of programming works and some of the basic JavaScript functionalities, but as I had no background or guidance, I did not get it's potential and went to learn Solidity.
Visit course
