backendGoAWSpayments

Open to senior backend roles · remote · UTC−3

I build fast, cheap-to-run backends in Go.

At Personare I moved ~15 payment and cart APIs off a PHP monolith to Go on AWS Lambda. Infrastructure costs dropped about 30% and read routes went from ~3s to ~5 ms. Checkout now handles ~10M requests and ~11k paid orders a month.

See my work Résumé (PDF)

Where I've worked

Résumé (PDF)
~15payment & cart APIs moved to Go
~5 msp50 on read routes, down from ~3s
−30%infrastructure cost

Software Engineer · Personare

Jun 2022 – present · Rio de Janeiro
  • Acted as backend lead on an engineering team of up to 10, reporting directly to the CTO. Bootstrapped the Go backend monorepo and its conventions (spec-first workflow, dependency boundaries, 80% coverage gates, OpenAPI contract tests), which the team adopted as its standard.
  • Ran the spike, wrote the stories and led the migration of ~15 payment and cart APIs from a PHP monolith to Go on AWS Lambda in 8 weeks, redesigning a rigid API contract with no rollback needed. Checkout now serves ~10M requests and ~11k paid orders a month across card, Pix, PayPal, Apple Pay and Google Pay.
  • Moved post-purchase work (confirmation email, analytics, Salesforce sync) off the critical path onto EventBridge and SQS with DLQs on the queue-backed steps, so a downstream failure never blocks a purchase. Added idempotency to retried flows and a transactional outbox.
  • Designed and shipped invoice issuing on Brazil's national e-invoice system (NFS-e) ahead of its 2026 legal deadline: ~11k invoices a month, 115k+ so far, 0.03% left pending.
  • Root-caused a 27% drop in an email alert product sending ~2.2M emails a day within 3 hours of detection, recalculated 1.25M users and wrote the postmortem.
  • Introduced alarms as code across 12+ services, where detection used to depend on users complaining, then removed ~107 noisy alarms so the rest get acted on.
  • Hardened payment security: a legacy card vault stopped retaining PAN and CVV, fixed open-redirect and authorization flaws, and led the same-day patch of a critical PHP-FPM RCE.
  • Moved a legacy WordPress commerce service from a single EC2 host to ECS Fargate and Aurora Serverless v2 with Terraform, runbooks and a rehearsed rollback.
  • Initiated and co-led the new internal admin (Next.js, plus Go on 15 Lambdas with an audit trail) that gives Support, Marketing and Product self-service.
  • On the Go astrology APIs (100M+ invocations a month), built the eclipses endpoint and migrated the Professional Chart from PHP with tests that diff it against the legacy output.
Go · Node.js · TypeScript · Next.js · React · AWS Lambda/SAM · AppSync GraphQL · CloudWatch · Terraform · MySQL · PostgreSQL · DynamoDB · Docker

Software Developer · Mundiware

Nov 2017 – Jun 2022 · Rio de Janeiro
  • Started as a web design technician and became a software developer within a year.
  • Migrated the ad management system behind the print classifieds of 5+ newspapers and the online classifieds of 3+ from Visual Basic to .NET Core with a web front end.
  • Built the TV ad management module.
  • Built ETLs that bring ads from several suppliers into the online classifieds automatically.
  • Extended the company's in-house template language with features that made web development easier and rendering lighter.
  • Trained two web designers.
C# · .NET Core · SQL Server · Visual Basic

Freelance Web Developer · Self-employed

2015 – 2022 · São Gonçalo, RJ
  • Websites and web apps for clients in several industries, owning scope, deadlines and delivery on my own.

Latest work

all →
lucantas2026
Morada: resident on mobile

Morada

Condominium management for admins and residents

  • Solo, end to end
  • Built for a real building
  • 900+ tests, 80% coverage gate
Open project →
lucantas2026
Diário SG: home page with the new visual identity

Diário SG

São Gonçalo's official gazettes, made searchable

  • Solo, end to end
  • ~162,000 acts indexed
  • MCP server with 12 tools
Open project →
See all work
About

Hi, I'm Lucas. I play with code for a living.

Backend engineer since 2017, freelancing since 2015. Go and serverless on AWS are home. I also write TypeScript and React when the product needs it, which is how I ship my side projects end to end. I got into this because building things is fun, and it still is.

I like ambiguous briefs and owning them end to end. On Longa, for example, I picked a rules engine over ML: less magic, but every plan change can explain itself, and it runs on the device with zero inference cost.

player 1 · lucas

Inventory

Goweapon
Node.jsweapon
PHPweapon
TypeScriptarmor
Reactpants
PostgreSQLshield
MySQLshield
AWSboots
Terraformboots
Dockerboots
Contact

Hiring, or have something to build? Let's talk.

I'm open to senior backend roles, full-time or contract, and to freelance projects. I work remotely from Brazil (UTC−3), in English or Portuguese.

lucantas.dev@gmail.com linkedin ↗ github ↗ Résumé (PDF)