Product engineering / Full-stack delivery

From idea to launch and beyond.

I work close to founders, users, and product teams to turn ideas into production-ready web products, solve the problems that appear in real operations, and keep improving the work after launch. I also join existing teams as an embedded senior engineer through staff-augmentation engagements.

Clear decisions, steady delivery.

01 / UnderstandClarify the problem, constraints, risks, and definition of done.
02 / ShapeTurn the work into a practical technical plan the team can execute.
03 / DeliverShip in small, verifiable steps with tests, communication, and a clean handoff.

One technical lead, with more capacity when you need it.

Flexible across the shape of the engagement.

Ownership

From requirements and implementation through testing, deployment, demos, production support, and ongoing improvement.

Team shape

Comfortable working independently or alongside tech leads, product managers, QA engineers, and other developers.

Duration

Engagements have ranged from focused three-month projects to work that continued for years.

Commercial model

Consulting engagements start at $65/hour. Longer commitments may be eligible for adjusted pricing, agreed during the proposal.

Product interfaces

  • React
  • TypeScript
  • Angular
  • Vue
  • Responsive web applications

Backend systems

  • Node.js
  • Python
  • C#
  • Java
  • Spring Boot
  • Go
  • Spring Data
  • Hibernate

Data and delivery

  • PostgreSQL
  • MySQL
  • Oracle
  • Kubernetes
  • CI/CD

Architecture and integration

  • Microservices
  • Third-party integrations
  • Full-stack engineering

US banking platform

Built a retail bank client-onboarding platform end to end

Problem
A retail bank needed a responsive client-onboarding flow and staff back office that could support multiple client paths while meeting KYC and regulatory requirements.
Approach
Owned the system from requirements gathering and architecture through release. Built Java and React features, integrated identity-verification, document-management, and Google Maps APIs, automated SFTP and email workflows, and added Cypress suites for every onboarding scenario.
Outcome
Replaced a manual intake process, automated recurring back-office work, and de-risked releases during a major platform overhaul.
  • Java
  • Spring Boot
  • React
  • Material UI
  • Cypress
  • REST APIs

Global payments platform

Moved critical payment flows from a monolith to services

Problem
A global payments product needed to evolve beyond a monolithic PHP application without disrupting payment operations across multiple regions.
Approach
Built React, Node.js, and Spring Boot services while maintaining the legacy PHP and Java systems in parallel. Helped teams find common ground during the migration, created internal libraries to speed up delivery, and added load balancing, health checks, and custom tracing across multi-application workflows.
Outcome
Helped move critical flows onto the new architecture while keeping the existing platform stable, making releases easier to verify, and improving visibility across distributed services.
  • Java
  • Spring Boot
  • Node.js
  • React
  • PHP
  • Sass

Healthcare communications platform

Strengthened reliability across critical clinical workflows

Problem
A doctor-patient messaging platform depended on reliable integrations and well-tested workflows while support issues created daily operational overhead.
Approach
Shipped backend features, integrated Twilio and DrChrono, maintained more than 800 unit and integration tests, and improved resilience with redundancy and circuit-breaker patterns.
Outcome
Improved platform reliability, enabled core clinical functionality, and automated reporting and support workflows that previously consumed staff time.
  • Java
  • Spring
  • Node.js
  • PostgreSQL
  • Kubernetes
  • Twilio
  1. Mar 2023—NowSenior Full Stack EngineerRetail Bank
  2. Jul 2022—Mar 2023Backend EngineerTrueNorth
  3. Jul 2021—Jul 2022Backend EngineerMedici
  4. Jun 2020—Apr 2021Software ConsultantIndependent Freelancer
  5. Mar 2020—Feb 2021Full Stack EngineerdLocal
  6. Jan 2018—Feb 2020Full Stack EngineerBlue Trail Software
  7. May 2016—Jan 2018Full Stack EngineerNetLabs
  8. Aug 2014—May 2016Java Software EngineerGEOCOM

Experience across systems that matter.

These examples focus on the systems, decisions, and outcomes while respecting client confidentiality.

Owned a retail-bank onboarding platform from requirements and architecture through release, including identity, documents, maps, SFTP, email, and Cypress coverage.

Retail banking platformEnd-to-end product ownership

Built and maintained more than 800 unit and integration tests while improving integrations, resilience, reporting, and support workflows for a healthcare communications platform.

Healthcare communications platformReliability and delivery engineering

The best first message tells me what is broken, what you have already tried, and roughly when you need it fixed. I’ll tell you honestly whether I’m the right person — and if I’m not, I’ll usually know who is.

Email: me@gaabmarquez.com