Lucas Maraz

Backend Engineer | Fintech

Buenos Aires, Argentina (UTC-3) | contacto@lucasmaraz.com | www.lucasmaraz.com | linkedin.com/in/lucasmaraz

SUMMARY

Backend engineer in Buenos Aires with 4+ years of experience. I work at Roxom, a Bitcoin-native capital markets platform, where I own the backend for compliance (KYC/KYB and KYT), the BTC-collateralized credit line and electronic invoicing, in TypeScript/Node with gRPC, PostgreSQL and RabbitMQ. Before that, almost three years at CRUCE building e-commerce in Go. UTC-3, compatible with US and EU teams.

EXPERIENCE

Roxom · Staff Engineer Dec 2024 - Present · Buenos Aires

Bitcoin-native capital markets platform and exchange (El Salvador). Backend owner for compliance, electronic invoicing and credit; 400+ PRs across 17 repositories, 1,800+ commits.

Owned the KYC/KYB integration with Sumsub, from the first standalone service to production: identity and company verification, signature checks on every webhook, 9 operations exposed to the back office over gRPC.
Owned the KYT transaction monitoring with TRM Labs: wallet screening, on-chain monitoring of high-value withdrawals, alerts and provider-downtime fallback; launched Oct 2025, author of its three core services.
Built the El Salvador electronic invoicing microservice (6 document types, PDF with QR, scheduled jobs); first document accepted by the tax authority in Jul 2026.
Took over the BTC-collateralized credit line (USDT/USDC) in Aug 2026: rebased the trading-account disbursement onto the new engine, made its transfer idempotent per loan and closed the pending product decisions.
In the user service, which serves thousands of accounts, I built 5 pieces: Google sign-in, phone and WhatsApp OTP with Twilio Verify, user preferences, portfolio history and the private membership tier.
Responded to an automated fake-signup campaign (~2,900 accounts, 17 operators identified by client fingerprint): Cloudflare Turnstile cut the bot's success rate from 100% to 9% in 4 hours; when it adapted, replaced it with reCAPTCHA Enterprise.
Fixed bugs across the stack, from a passkey registration bug that locked 5 users out (fix in production 2 days after merge) to duplicate accounts from Gmail dot variants (0 new duplicates after the fix).
Built 5 LogQL alert rules and one SQL rule on Grafana/Loki for abnormal transfer, withdrawal and login volumes, and a post-release regression detector (about 70 queries per run) that reports to Slack.
Designed and shipped the pre-KYC country eligibility step across backend, gateway and frontend, with rules by nationality and country of residence; in production since Aug 2026.

CRUCE · Software Developer Mar 2022 - Nov 2024 · Remote

Custom software for e-commerce on VTEX and Tiendanube. Backend services in Go and Node/TypeScript: REST and GraphQL APIs, Redis and MongoDB, Docker and GitHub Actions pipelines, AWS (S3, ECS, CloudWatch).

Integrated Sage X3 with VTEX for a B2B e-commerce: 10,000+ products with stock and prices pulled over SOAP/XML with cursor pagination and incremental sync by last-modified date, loaded through the VTEX API; stock reserved in Sage on order creation and released on cancellation.
Rewrote the checkout cart stock check in Go with concurrent Sage queries: from 30 to 2.5 s.
Ran stock and price sync for two more clients: an online pharmacy on VTEX that delivered its files over SFTP, and a B2B wholesaler on Tiendanube.
Introduced Go to the company: shipped its first Go service to production and ran 3 training sessions for the developers, including juniors.
Built and maintained the CI/CD pipelines (Docker, GitHub Actions) for 5 services, with automated tests and a weekly deploy per service, and ran production deployments when the senior was out.

SKILLS

Backend: TypeScript, Node.js (20-24), PostgreSQL (migrations, advisory locks, partial indexes), gRPC (ts-proto), REST, RabbitMQ, Redis, hexagonal architecture, Turborepo monorepo

Security & compliance: WebAuthn/passkeys, TOTP, OAuth 2.0 (Google), JWT rotation, step-up auth, webhook HMAC verification, reCAPTCHA Enterprise, KYC/KYB (Sumsub), KYT (TRM Labs), AML cases, Snyk

Infra & observability: AWS (EKS, ALB, ECR, S3, CloudWatch, Athena), Kubernetes, Helm, Flux (GitOps), Docker, Cloudflare, GitHub Actions, Grafana, Loki (LogQL), Prometheus, Metabase

Testing & tooling: Jest, Vitest, MSW, integration tests on real Postgres, Python scripting, Claude Code (MCP, skills, subagents), Linear

Also: Next.js (App Router), React, TanStack Query, Tailwind; Go (2022-2024); GraphQL, MongoDB

EDUCATION

Universidad de Buenos Aires · Licenciatura en Ciencias de la Computación (BSc CS), in progress 2025 - present

Languages: Spanish (native), English (B2, professional working proficiency).