Calin Gabriel Backend Developer · Node.js / TypeScript
Available
Portrait of Calin Gabriel

Cluj-Napoca · remote EU or hybrid · contract or permanent

Backend developer,
Cluj-Napoca.
Node and TypeScript.

Most recently I worked on the crypto custody platform Bitpanda builds for banks, where I owned the address book — the part that checks an address is valid before a customer's funds can be sent to it. Before that, ImmoScout24 in Austria and RWE in Germany, both long-running platforms that had to keep working while they changed. Backend is where I'm strongest, but I've shipped the React side of the same products and the integrations sitting between them.

A few numbers
45 → 12 min
RWE export pipeline, moved to worker pools
≈ 65%
faster API responses after migration
15,000+/day
energy-market queries served
2,000+/day
documents through a React + Node pipeline (Endava)
Work

What I work on.

Roughly four areas, with the project each one comes from.

  1. BACKEND

    Backend work in regulated systems

    At Bitpanda I owned the crypto address book: the API, the data model, the validation rules, the tests and the release. In custody, an address accepted by mistake can mean funds nobody gets back, so most of the work sat in the validation and the failure cases rather than the happy path.

    Project Bitpanda — institutional crypto custody for banks.

  2. MIGRATION

    Legacy Java into Node and NestJS

    At RWE we moved legacy Java components to NestJS in slices, with integration and E2E tests around each slice, so day-to-day delivery could keep going while the migration ran underneath it. Small team, live production system, no appetite for a full rewrite.

    Project RWE — Java to NestJS on an energy-market platform.

  3. PERFORMANCE

    APIs and data access that got slow

    I profile before changing anything. At RWE that meant finding the real bottleneck in MongoDB aggregations serving about 15,000 queries a day, then moving CPU-heavy exports onto Node worker pools so they stopped blocking normal API work.

    Project RWE — around 65% faster API responses; exports from 45 minutes to 12.

  4. PRODUCT

    Product work across React and Node

    React and Node in the same week, usually with somebody else's platform in the middle. At ImmoScout24 that was Iterable wired into lifecycle messaging — mostly mapping their data model onto ours and making the failure modes visible. The platform was tested at every layer and matching that bar took me a while.

    Project ImmoScout24 — Iterable lifecycle integration, plus search, listing and SEO across React and Node.

Background

How I got here.

Start

First job at 16.

I won an internship contest in Galați and turned it into my first software job, doing Linux and web work on things people actually used. Computer Science at Babeș-Bolyai came after, and mostly it put names to things I had already been doing.

Since

Backend, mostly in data-heavy or regulated products.

DeverSoft, WIP Romania, Endava, RWE, ImmoScout24, Bitpanda. Restaurant systems, a wallet, scientific publishing, payments, energy-market data, property listings, and most recently crypto custody. Node and TypeScript throughout, with enough React that I can work on both sides of a product.

Next

What I am looking for.

Remote in the EU or hybrid in Cluj, contract or permanent. I would like to stay somewhere long enough to actually learn the domain, on a team that owns what it builds.

Projects

Projects.

Four of them, with what I actually did on each.