Talysson Oliveira

About

Software engineer, end to end.

I design and build the full stack of a product — data model, API, frontend, and the automated tests that keep it truthful — with a focus on architecture that stays maintainable as a system grows.

Founder & Full-Stack Engineer at Leangency, a web agency I run in London — right to work in the UK, no sponsorship required.

What I do

A summary grounded in the codebases I've actually shipped, not a résumé template.

My recent work spans two poles of the same discipline: production e-commerce (storefront, checkout, payments, media pipeline, a 5,400+-test suite) and AI-native backend architecture (a CRM built on Hexagonal Architecture and Domain-Driven Design, with an isolated AI worker running LangChain and CrewAI). Between those, I've built the internal platforms for Leangency, the agency I run — a lead-qualification pipeline and a multi-tenant client portal on a headless CMS — and shipped standalone client-side tooling with no backend at all.

The common thread is ownership of the whole system: I don't just write the feature, I own the schema it depends on, the tests that prove it works, and the boundary that keeps it from leaking into everything else.

Skills

Technologies used in production or in active builds across the projects on the Home page.

  • Frontend

    • Next.js
    • React
    • TypeScript
    • Tailwind CSS
    • Radix UI

  • Backend & data

    • tRPC
    • Node.js
    • Prisma
    • PostgreSQL
    • Supabase
    • pgvector

  • AI & automation

    • LangChain
    • CrewAI
    • Ollama
    • OpenAI API

  • Commerce & content

    • Stripe
    • Cloudinary
    • Sanity CMS

  • Testing & quality

    • Vitest
    • Jest
    • Playwright
    • TypeScript strict mode

  • Infra & tooling

    • Turborepo
    • pnpm
    • Docker
    • GitHub Actions
    • Vercel

Trajectory

How the work has grown in scope — ordered by architectural complexity.

  1. Standalone client-side tooling

    Payment Analyzer Professional: a dependency-free PWA doing PDF parsing, rule-based calculation, and reporting entirely in the browser. No backend, no framework — proof that a real problem doesn't always need a server to solve it.

  2. Full-stack production commerce

    Julia Mendes: a complete storefront — catalog, cart, Stripe checkout, admin dashboard, media pipeline — shipped to production and backed by a 5,400+-test suite.

  3. Internal platforms for a real business

    Client Acquisition OS and Leangency Portal: automation and a multi-tenant CMS-backed portal built for Leangency, the agency I run — not a demo, real workflows and real data ownership.

  4. Architecture-first systems

    IntelliFlow CRM: a monorepo built around Hexagonal Architecture and Domain-Driven Design specifically so the AI layer, the database, and the integrations can each change without the domain logic knowing or caring.