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Senior software engineer and engineering leader, fifteen years in. I work where the problem is still ambiguous: understand the operation, decide what to build, design the system, form the team, and keep it running while it changes. Realtime, integration-heavy and legacy-bound systems are my usual ground. I have founded engineering functions, I run a company, and I stay hands-on in the code of what I lead.
Now
The two run in parallel.
What I bring
Reading an operation before there is a ticket: which decision matters (build or buy, which vendor, which architecture), what the people on the floor actually need, what to leave out. Then the proposal, the comparison, and the thing shipped.
Live state instead of reports, integration with the physical world (telematics, health records, ERPs, payment rails), and migrations designed as two-way sync with a cutover, so the system changes while it serves people. TypeScript, Node.js, React, Firebase and Google Cloud most of the time.
Founding an engineering function from zero, hiring and code review, on-site and offshore squads treated as peers, reporting to boards. Promoting successors and staying close enough to the code to make the hard calls.
Selected work
Problem. A large carrier had to decide between licensing a fleet system and building one. Jobs data, telemetry, fuel and maintenance lived in separate tools.
Decision. Came back to Lenarge with a proposal to create a technology directorate, approved in five business days. Compared four paths (external vendor, hybrid, in-house, licensing) and made the case to build. Senior staff engineer at first, CTO from 2021.
System. Founded the engineering function and designed the platform: live fleet state in Firebase Realtime Database, so every screen is a view and every integration a writer; one TypeScript codebase shared across web, mobile and functions; 15+ telematics vendors integrated. Responsible for its architecture through five versions.
Result. In production for 20,000 partner drivers and 30,000 trips a month. Monthly driver rewards run for about 800 drivers without a spreadsheet. Gerdau and Aperam among the clients.
TypeScript · Firebase Realtime Database · MongoDB, PostgreSQL, SQL Server, BigQuery · Oracle Transportation Management integration for Gerdau
Problem. At the start of the pandemic, the teleconsultation app of Brazil's largest self-managed health plan was failing under load. Patients waited hours and were not seen; sessions crossed between users.
Decision. Asked to work alone on the code instead of joining the consultancies' debate, and to replace only the layer where patients connected, not the whole system.
System. A new realtime layer on Firebase: device presence with automatic cleanup, queues on native indexes, optimistic transactions so two clinicians cannot take the same patient, Twilio Video for sessions, two-way sync back to the PHP/Laravel and Parse Server legacy. Written over one weekend; an offshore squad finished the rest under my coordination.
Result. Swapped in without downtime. The queue, previously a black box, became a live dashboard for doctors and nurses. The platform went on to 500,000+ consultations.
Problem. A primary-care program for hospital staff needed digital scheduling and consultations on top of the electronic health record already in use.
Decision. Integrate with the electronic health record already in use instead of running a parallel patient record for the program. My call, and the one that kept the program inside the hospital's data governance.
System. Philips Tasy EHR (.NET Core, Oracle) connected to the InterSystems HealthShare bus: patient base, rosters, VPN, SFTP, deployments under hospital change control. Technical lead in weekly reports to hospital leadership.
Result. Pilot live in July 2021, with corrections shipped to production in the following weeks.
Problem. Hired for the mobile app; within days asked to rebuild the platform. An order book needs write consistency under concurrency, and the balances are real.
Decision and system. Led the rebuild of wallet and exchange on transactional writes, with one client SDK for web and mobile; ran code review, hiring and releases as technical lead.
Result. About US$2M in custody on the AllCoinWallet platform. Orderly decommissioning conducted in December 2019: orders cancelled, withdrawals processed, balances reported.
Problem. Producing software got cheap. Knowing what a company's code actually does, and what not to build, did not.
Decision. The output is a decision document for a board, not a chat transcript for a developer.
System. Agents read a company's repositories through a three-level knowledge layer (project, repository, module), with staleness control by source hash and an explicit context budget.
Result. First engagement, seven repositories: three P0 defects surfaced in the first session, including an unauthenticated public endpoint; and a single-tenant vs multi-tenant decision, authored by me and revised in writing when the team found a cheaper path, that avoided a refactor estimated at several months.
More in the full CV: Gerdau's Oracle Transportation Management integration, Volvo telemetry turned into driver rankings, a driver monitoring department proposed and led, reporting to the legal directorate, and the companies that did not work out.
Weighing a build or buy call like this one? Write to me and I will tell you how the comparison went here, and where it would not apply.
Journey
Before the two roles at the top of this page.
Speaking and community
The Developers Conference 2023, Node.js track: "Unlock realtime mode in your apps", on the fleet platform's architecture. Published on the conference's channel.
Firebase BH, founded in 2017 eleven days after Google I/O; spoke alone at the first meetup and published a starter kit the next day. Also organized Vue.js BH and coding dojos.
Public code: async-task-runner-js, cordova-plugin-firebase-native, firefunctions.
Not in the list above: the things that did not work. An agency lost to an attack in 2010, a freight startup that closed in four months. Both are in the CV, because they changed how I build.
Putting together a track, a meetup or an internal session? Write to me if that talk fits what you need.
Contact
Email is best: neilorcaldeira@gmail.com. Also on LinkedIn, GitHub and Instagram.
Write about a system that has to go into production and stay there, a build or buy call you are weighing, an engineering team you are putting together, or a talk you need.