Taking a hands-on engineering role here was a deliberate choice: after 11 years as CTO, I wanted to go deep on DeFi architecture next to the engineers who audit it, so that when I manage delivery in this space I know exactly what I'm asking a team to build and what it costs. At 33Labs (formerly 33Audits), I've worked on advanced DeFi protocols, and the company's roots as a smart contract auditing firm have sharpened a conviction I carry into project decisions: security and feasibility have to be weighed at the architecture stage, before a single requirement gets locked in.

COZ is the first and most well-known group of developers on the Neo network, renowned for numerous significant projects within the ecosystem. After years of partnership, I was honored to be invited to join the group's board of directors.

I co-founded Simpli as a two-person startup focused on building a B2C mobile product, which quickly evolved into a fast-growing software house serving a wide range of clients. In its first year, the company pivoted to delivering custom distributed applications and scaled organically through consistent delivery and client satisfaction. Over 11 years, we delivered 50+ successful digital products for both startups and enterprise clients, while also launching and maintaining our own proprietary platforms.

From the beginning, Simpli was an early adopter of emerging technologies like mobile development and blockchain. I played a key role in shaping both the technical direction and business strategy of the company, leading system architecture, technical roadmaps, and documentation, and building an engineering org of 30 including 5 team leads. My work ranged from hands-on technical leadership to driving innovation through research, process design, and technology adoption — helping turn product ideas into real businesses by aligning technical execution with market opportunities.

Provisioning AWS infrastructure was a recurring part of that work. With 50+ projects, we needed a standard: a checklist for spinning up a new account, a baseline set of IAM roles, and a reusable Terraform starter kit so no project's infra started from a blank page — the same template became a paved road that sped up every project's first deploy. Cost optimization started reactively, after a client flagged a high AWS bill, but past a certain point we set up anomaly-alert triggers instead of waiting for the next complaint.

Enclave is a Wallet built to embrace non-blockchain users. It combines cutting edge technologies like Abstract Accounts, WebAuthn and Gasless transactions to make onboarding as smooth as a traditional web application — paired with a full on-chain activity explorer. Working with a small team, I was responsible for the product vision, usability, and development of the whole wallet frontend, contributed to the Smart Contracts, and led the system design of the indexer and API behind the explorer. One example of that indexing work: handling chain reorgs. Every block was stored keyed by its own hash and its parent's, so detecting a reorg meant walking back parent hashes until the indexer found one it already had — the fork point. From there, the orphaned blocks and the balances derived from them were invalidated, and the canonical chain was replayed forward through idempotent handlers, so reprocessing never double-counted a transaction.

Simpli estimated at two levels: the high-level delivery estimate I gave the client, and the granular per-task estimates the developers made themselves. The two drifted apart with nothing to show where. I built ClickClock, a ClickUp companion for time and performance data, to make both gaps visible — it began as a proof of concept from a need I hit while managing the team, then grew with the team's own input on organizing and prioritizing demands. We set a target of no task landing more than 2h off its estimate: breached often at first, then rare once the data went back to the developers as feedback.

Neon is the leading wallet in the Neo ecosystem, with over $1 billion in traded volume. I was responsible for architecting its mobile version and later contributed to the desktop app. During my time on the project, I tackled key challenges such as supporting multiple blockchain networks, managing multiple accounts simultaneously, implementing WalletConnect integration, and developing the protocol for network interaction, along with several other critical integrations.

Sharity was a crowdfunding platform for charitable causes that I built from creation through scaling, growing it past 100 thousand users. It was eventually sold to Abacashi, a bigger competitor, and I was invited to lead the engineering side of that merger in recognition of the quality of Sharity's system — refactoring Abacashi's legacy C#/Angular codebase over to Node.js and React with the platform staying live the whole time, using a Strangler Fig strategy to migrate it piece by piece instead of a big-bang rewrite. One example of the work on Sharity itself: an event-driven achievements system, with badges and real-time progress bars for challenges that could chain off one another. Business events flowed through SQS, and idempotency was enforced by inserting each event's ID into a dedupe table in the same MySQL transaction as the counter increment, so a duplicate delivery just aborted instead of double-counting; chained challenges unlocked themselves by publishing a follow-up event back onto the queue, with no need for global ordering. It held up at 100k+ users, and was later reused as-is inside Abacashi after the merger.

Louis Dreyfus Company, one of the largest commodity traders in the world, commissioned a 'Safety, Health, and Environment' management platform for use across all its global units — each with its own local regulations, forms, and reporting requirements. I owned it end to end: architecture, development, and integration with Azure Active Directory for authentication and user management. The core challenge was translating that sprawl of per-unit requirements into one flexible application instead of one branch per country, so I modeled forms, fields, and workflows as configurable data instead of hardcoded screens — letting a compliance team in a new unit stand up its own SHE process by configuring the platform, not by requesting a code change and a deploy.

Jamef, the largest shipping company in Brazil, needed a new dashboard for customers to track delivery data, but the existing one suffered from severe performance problems. My scope started as frontend-only, but tracing the slowness back to its source pulled me into the data layer. I introduced a caching layer and a server-side pagination policy for the result set, taking a query that took 8 seconds down to a few milliseconds. I delivered a complex dashboard with several customized graphs and contributed to restructuring the underlying central system.

I was the lead engineer who built iTrack Brasil from the ground up, owning its system design through its first two years and scaling it into a B2B delivery platform integrating multiple systems, with nearly 60,000 couriers and over 50 million invoices processed across 2,000 registered companies — growth that led to its acquisition by MadeiraMadeira in 2021. Simpli carried the product through that acquisition and ran it for three more years before handing it over to MadeiraMadeira in 2024, with me on it as CTO, coming back alongside the team hands-on when the work needed the depth. One of those returns: as invoice volume and courier position updates grew, the database hit a write bottleneck, surfaced by a spike at the end of a fiscal month. The system stayed up, but latency and AWS costs climbed, so I redesigned the write path at its source — courier position pings now land as Parquet files on S3, backed by a Redis cache holding each courier's last known position for fast reads, while invoice processing moved behind an SNS/SQS pipeline that absorbs bursts asynchronously.

Apptite was a food delivery app for iOS, Android and the web. It gained recognition with acceleration by '500 Startups' and media coverage that established it as an important platform in the artisanal food market. I was the main engineer responsible for the platform from its initial planning and structuring through scaling it as it grew. One example of that scaling work: the dish recommendation engine. The map was discretized into cells, each holding the list of stores that served it, updated in batch whenever delivery areas changed — so the geographic lookup itself was just a cached read. Personalization ran on top of that already-filtered set, combining complementary signals in parallel (repurchase history, regional popularity, among others), with the heavier estimates — including a store-by-cell matrix — precomputed offline.

Desabafa was an anonymous social network built for emotional support and mutual understanding, and it went on to receive media recognition in the mental health sector while reaching 700 thousand posts. I was responsible for planning, structuring, and building the platform, including its moderation and safety systems. One example of that work: anonymity was the whole point of the product, so any moderation approach that relied on identifying users to punish or filter them was off the table. I built the safety layer around behavior instead of identity — rate-limiting and pattern detection on posting activity, plus keyword and pattern-based flagging tuned for crisis language — so harmful content and abuse could be caught and escalated without ever unmasking a user.

Multilaser, one of Brazil's largest cell phone and tablet manufacturers, faced high demand for quality control testing that had been done by hand on the assembly line. I led development of the Android app that automated it instead — running CPU, RAM, GPS, screen brightness, and touch checks — and it has since tested over 20 million devices. One example of that work: each check had its own pass/fail criteria and its own margin for hardware variance, so the real problem wasn't running the tests, it was collapsing five independent, noisy hardware signals into one deterministic pass/fail a line worker could act on in a couple of seconds, fast enough to keep up with a production line moving tens of thousands of units.

Brazil's official internet quality measurement tool. I led its migration off Java Applets to plain JavaScript.

My first three engineering jobs — web applications in PHP and Java, JavaScript front-ends and MySQL.