Gabriel Lago

Professional with a solid track record in Information Technology, with deep knowledge and command of Software Development. I have worked for national and multinational companies across business areas such as Banking, Insurance and Retail. Communication – Ease in presenting concepts and ideas to different audiences and profiles. Organization and Commitment – Always aiming to carry out activities in a balanced way and with quality.

Software Engineer at Mercado Livre (2024-07 – Present)

• Developed and evolved a BFF in Go/GraphQL, integrating infrastructure, permissions and change-control services to simplify consumption by frontends.
• Implemented import and deletion flows for Terraform stacks, with failure handling and visibility of the result to the user.
• Developed governance controls for infrastructure changes, including staged approvals, policy evaluation and integration with corporate identity.
• Implemented contingency operations and authentication, authorization and auditing controls, preserving access granularity as contracts evolved.
• Carried out the migration of Terraform states between AWS accounts using S3, SQS, Lambda and Python, with capture of new writes, backfill and integrity reconciliation.
• Took part in the design and delivery of a deployment scheduling solution, implementing the engine with EventBridge and SQS, idempotency controls, BFF integration and authentication for PCI operations.
• Evolved a Go CLI with parameters for automation, plus a pipeline for building, versioning and distributing binaries.
• Fixed vulnerabilities, updated runtimes and resolved failures in Kubernetes/GitOps environments. Published observability guidelines to increase developer autonomy.
• Wrote RFCs and ADRs for cross-team initiatives, including a proposal for a multicloud architecture for infrastructure execution.

Software Development SR Analyst (Platform Security) at Mercado Livre (2021-06 – 2024-07)

Worked in a build & run model following agile framework practices (Scrum/Kanban). Technologies used: Terraform, Golang, Node.js, Java 8, OAuth2, AWS ECS, AWS SQS, AWS API Gateway, AWS Lambda, Envoy, MAC algorithms, x509 certificates.

• Development of features using symmetric (HMAC) and asymmetric (RSA) algorithms, and creation of SDKs (Go, Node.js and Java) to ease the integration of internal products by other teams, with the goal of protecting financial transactions through proof-of-possession techniques. This mechanism protects 20M+ financial transactions daily, reducing ATO (Account Takeover) and man-in-the-middle attacks.
• Development of a Proxy Gateway mechanism for Mutual TLS (mTLS) authentication on AWS infrastructure, using third-party gateway tools and integration with DCR (Dynamic Client Registration), meeting the transaction security requirements of Open Finance Brasil.
• Development of an OAuth2-based authentication service for onboarding Sellers to the Pix Saque and Pix Troco products.
• Guardian of uptime for the applications owned by the team, helping keep it above 99.9%.
• Support during incidents and development of post-mortem actions.
• Application of resilience and reliability best practices.
• Collaboration with and support for the development of peer team members.

Software Engineering Specialist at C&A Brasil (2020-01 – 2021-06)

Responsible for back-end support between the partner (VTEX) and the sales app as a BFF (Backend for Frontend) layer. Monitored and performed production deployments, using a customized Git Flow to ensure a stable version of the code is always available. Knowledge of internal integrations beyond the BFF layer, such as order integration and refund processes. Reviewed MRs (merge requests) to ensure alignment with the requested demand. Implemented blue-green deployment to avoid impacting end customers during deploys. DDD-based architecture for new projects; for legacy projects, a cleaner-code approach was pursued through micro-refactoring and TDD adoption.

Technologies used in these projects: Node.js,.NET Core, MySQL, Oracle, Redis, Git, Git Flow, AWS EC2, AWS Lambda, AWS Beanstalk, OpenShift containers, GitLab Registry (container and package), GitLab CI/CD, VTEX, PM2, Docker, ELK, AWS CloudWatch.

Support Developer Analyst at C&A Brasil (2018-05 – 2020-01)

E-commerce back-office support. Projects involved: Using AWS EC2, SQS, Lambda, S3, Node.js, PM2, OracleDB, MongoDB, VTEX.

• Order integration between the sales platform (VTEX) and the distribution center WMS;
• CRM: customer enrollment and benefit assignment;
• After-sales (returns): project integrating customer service with internal refund systems;
• APIs integrating e-commerce with VTEX;

Senior Software Developer at BRQ (2016-11 – 2018-04)

Node.js Web Developer at Advus Corporation (2016-06 – 2016-09)

Development of REST APIs and Single Page Applications (SPA) using Angular and Node.js.

Mid-level Programmer at BRQ IT Service (2010-07 – 2016-06)

Providing services to Banco Itaú across several technologies: Java, Vignette WEM, ASP.NET MVC3, HTML, JavaScript, Node.js, Spring MVC, IDE RAD (Rational Application Developer), Dicionário (the bank's proprietary tool), ASP.NET 3.5, Genesys framework. Some projects used the Scrum methodology.

BRQ - Itaú (2014-10 – 2016-03)

Creation and maintenance of REST API modules to be consumed by new and legacy products, using Node.js/JS, Express, Swagger, Validator, Express-Validator, Async and native Node.js modules.

BRQ - Itaú (2014-07 – 2014-10)

Worked on the front end of the new Internet Banking (Java), Spring MVC and workspace products, using the Scrum methodology. Development of new modules, maintenance and improvements to the websites, using Java, JSTL, Scriptlet, Taglib, HTML, CSS, JavaScript, jQuery and Eclipse IDE.

BRQ - Itaú (2013-06 – 2014-06)

Worked with Vignette, WEM and workspace products, DSM methodology and Scrum framework. Development of new modules, maintenance and improvements to the websites [itau.com, itau.ri], using Java, the Vignette platform (Javadocs API), JSTL, Scriptlet, Taglib, HTML, CSS, JavaScript, jQuery, WAS and IDE RAD (Rational Application Developer).

BRQ - Itaú (2013-05 – 2013-07)

Created the statement, history and points features for the Sempre Presente website, using ASP.NET MVC3, Razor and jQuery, consuming WCF services.

BRQ - Itaú (2010-06 – 2013-01)

Worked with Dicionário, the bank's proprietary tool, using HTML, CSS, JS and jQuery on the front end and Dicionário (Universal) on the back end, using SQL Server in some cases to manage user information.

BRQ - Itaú (2011-01 – 2011-05)

Created the cardholder chat using ASP.NET 3.5 and the proprietary Genesys tool.

Postgraduate Degree in Distributed Software Architecture, Information Technology – Pontifícia Universidade Católica de Minas Gerais (2022-09 – 2024-01)

Cyber Defense, Information Technology – FIAP (2020 – 2022)

Information Systems, Information Technology – Universidade Bandeirante de São Paulo (2016 – 2017)