Johnson Mauro

Professional experience

1. Software Engineer · InPhonex

   Jan 2022 - Present
   • Co-led the rewrite of a 227k-line telephony admin app from React 16/CRA to React 19, Vite 8 and TypeScript 6: 788 commits, #2 of 22.
   • Grew test coverage from zero to ~3,000 cases and 71.5% of lines, adding 459 test files with Vitest and Testing Library.
   • Built a CRM-to-telephony integration end to end, with a 14-module API, embedded calling SDK and 985 tests, using NestJS, NATS and Playwright.
   • Standardized AI-assisted delivery across 4 team repositories with 26 Claude Code skills and ~1.2k lines of agent context.
   • Cut dependency install size 37% (720 to 454 MB) by migrating Yarn to pnpm.
   • Shipped 1,135 commits to the 12-year-old AngularJS product while the rewrite progressed.

2. Partner & Software Engineer · ERP startup

   May 2026 - Present
   • Built a field-sales mobile app solo in 6 weeks: 92 commits, 13 screens, ~18k lines, using Expo SDK 56, React Native 0.85 and TypeScript.
   • Designed offline-first ordering across 8 DDD modules, queuing orders in on-device SQLite and syncing in the background.
   • Wrote ~347 unit and component tests; 53% of commits were paired with Claude Code, guided by 8 custom project skills.
   • Delivered the ERP returns module in 5 phases (~6k lines), covering the .NET 10 API, a React wizard and returns e-invoicing.

3. Freelance Software Engineer · Freelance clients

   Sep 2025 - Present
   • Shipped a bilingual English-school platform from v1.0 to v2.4: 91 commits, 14 merged PRs, push-to-deploy CI, built with Next.js 16.
   • Reached Lighthouse mobile scores of 96 accessibility, 100 best practices and 100 SEO after a WCAG 2.2 AA pass.
   • Closed a 10-finding OWASP-aligned audit, adding HSTS, CSP and COOP headers and patching 16 vulnerable dependencies.
   • Designed a multi-tenant REST API with 19 endpoints, role-based JWT and 11 documented ADRs, tested against real PostgreSQL in Go.

4. Open-source contributor · Browser extension for a game trading site

   Jul 2026 - Present
   • Merged 2 PRs into a 38k-line Chrome and Firefox extension, including a scroll bug fix backed by 9 regression tests (Svelte 5, WXT).

5. Software Engineer · Accountfy

   Oct 2021 - Feb 2022
   • Delivered front-end features, proofs of concept and tech-debt removal in 5 months, and trained the team (AngularJS, Commerce Cloud).

6. Software Engineer · IT Lean

   Oct 2020 - Aug 2021
   • Built the front end of Leanbot, a proprietary conversational-AI product, over 11 months (Angular, PO-UI, Node.js, PostgreSQL, AWS).

7. Software Engineer (parallel side project) · nevtec.eu

   Jan 2020 - Jun 2021
   • Delivered on-demand front-end work as a freelancer for 18 months (React, React Native, Node.js, GraphQL).

8. Software Engineer · Foco Aluguel de Carros

   Jun 2020 - Aug 2020
   • In 3 months, built Coral, a fleet check-in and check-out system, and ran client and supplier meetings (Angular, Node.js, MySQL, Power BI).

9. Software Engineer · Devexo (OrtoClin)

   Aug 2019 - Jun 2020
   • Developed a dental-health product across 2 platforms, web and mobile (Angular, Ionic, React Native, .NET Core, SQL Server).

10. Associate Software Engineer · Avanade

    Jun 2018 - Aug 2019
    • Delivered 8 Power BI dashboards for 3 top-tier Brazilian telecom operators, cutting executive report lag from D+5 to D+1.
    • Built 5 RPA bots that eliminated ~30 back-office hours per week across billing and ticket triage.
    • Migrated ~2M rows/day from legacy mainframe tables into a SQL Server warehouse through a scheduled ETL pipeline.

11. Software Engineer · Tella World

    Jan 2018 - Jun 2018
    • Built the front end of iBoltt, a ride- and delivery-sharing mobile app, in 6 months (AngularJS, Node.js).

12. Software Engineer · Qualytech

    Oct 2012 - Dec 2017
    • Over 5 years, built ConsegnaERP for small businesses and ran software-factory projects for utility, education and real-estate clients (WebForms, .NET, SQL Server).