Build and deliver high-quality applications, from development to testing to deployment

Expert freelance services for software development, test automation, and DevOps

Meet Dennis

As a freelancer and consultant, I work with tech organizations worldwide to help them build effective, high-quality software. It's my mission to help these companies get their idea off the ground quickly and in the right way for the long haul.

For over 20 years, I've worked with startups and other tech companies across the globe to help them successfully build effective, high-quality software. My experience comes from working with early-stage companies in New York City, San Francisco, Tokyo, and remotely with dozens of organizations around the world.

My main areas of focus are full-stack web development, test automation, and DevOps. I love sharing my thoughts and expertise around test automation on my blog, Dev Tester, and have written a book on the same topic.

Dennis Martinez - Photo

What others say about working with me

    • We've benefited a lot from Dennis's skill and expertise in backend development, DevOps, automated testing, and CI/CD. Dennis is not only reliable, he handles challenges with a mix of rational problem-solving and big-picture thinking. He's recommended solutions and chosen technology that fits our context and needs as a startup. His eye for process and detail is to be envied and has become the gold standard for members of our development team.

      Allen W.
      Co-Founder @ Sollective K.K
    • Dennis is one of those guys who can do just about anything. We worked together on a pretty tricky port of a Rails/Ember.js app from Heroku to being able to run standalone in Docker and he solved all of the difficult parts. Hire him as quickly as possible.

      Jay G.
      Ecor Rouge
    • Dennis was extremely generous in sharing his knowledge and genuinely wanted to help us out. He looked at our situation and within hours was able to tell us why what we were trying to do wasn't working, what needed to be fixed, and gave us alternative solutions if we wanted to change course. Dennis provided exactly the type of expert guidance we desperately needed.

      Cindy W.
      Senior Technical Business Analyst @ Onsite Rental Group
    • Over the years, Dennis has been easy to work with, always patient to explain what he was doing, and was very dependable on results. He went the extra yard to find a solution which kept our application up and running, plus ensured we can continue to do so without interruption into the future. I highly recommend Dennis, without reservation, for any development job, big or small. He is great to work with!

      Richard Halpern
      Founder @ EcoApprentice
    • Over the years I have worked with Dennis on a variety of custom software projects, across the full stack of backend and front end applications, for a number of different clients. In every scenario, he is one of the best software engineers on our teams in terms of pragmatic problem solving, consistent communication, and on-time delivery of the needed solutions. I cannot recommend Dennis highly enough for anyone considering to bring him on their project or team.

      Randy Burgess
      VP of Technology @ MPI Media Group
    • Always a pleasure to work with! Dennis is highly professional and very quick to respond. I wish all my contractors (and employees) were as incredible as him.

      Project Manager @ Mogu Technologies

Latest Articles

Software Engineering and DevOps articles containing expert insights, tutorials, and resources for tech professionals

Article cover for Get Started With Hetzner Cloud and Terraform for Easy Deployments
Get Started With Hetzner Cloud and Terraform for Easy Deployments

Learn how to deploy and manage servers on Hetzner Cloud using Terraform to ensure the long-term maintainability and scalability of your infrastructure.

Article cover for Automating Rubocop Into Your Rails Development Workflow
Automating Rubocop Into Your Rails Development Workflow

Do you have Rubocop on your Ruby on Rails application? Here are some ways to run it early and often to maintain your code for the long haul.

Article cover for Setting Up Rubocop for Legacy Ruby on Rails Projects
Setting Up Rubocop for Legacy Ruby on Rails Projects

Overwhelmed after setting up Rubocop in your legacy Rails apps? Here are some tips to clean up your old codebase for long-term maintainability.

Free Resources

Dive into our collection of free resources to help your business excel

The Hidden Costs of Ineffective Test Automation - Guide Cover
The Hidden Costs of Ineffective Test Automation

Your test automation might cost you much more money than you expect. Get this free guide today to learn about these problems and take steps to maximize your investment in automated testing.

Hiring a DevOps Engineer: What You Need to Know - Guide Cover
Hiring a DevOps Engineer: What You Need to Know

Find out how to hire the right DevOps engineer with this free guide to boost your organization's ability to deliver high-quality products and ensure it can tackle any technological challenges that come its way.

Simple Yet Powerful Ways to Shrink Your AWS Expenses - Guide Cover
Simple Yet Powerful Ways to Shrink Your AWS Expenses

Are you tired of receiving hefty bills from AWS every month? Download this free guide and begin taking small steps to help reduce your AWS bill and cut down on unnecessary cloud expenses today.

Some of my work

End-to-End Testing with TestCafe Book Cover

End-to-End Testing with TestCafe

Learn how to build robust end-to-end tests on a real web application using TestCafe. Let the End-to-End Testing with TestCafe book be your guide to learn how to use TestCafe for writing effective end-to-end tests for any web application. Improve the quality of your code, boost your confidence in your work, and deliver faster with fewer bugs.

Dev Tester Logo

Dev Tester

The Dev Tester blog contains articles about automated testing and test automation. Since 2020, I've been writing to help others become a better tester.

Serverless Video Clipper

Serverless Video Clipper

A serverless application provisioned with Terraform for creating a fully-automated video clipping service on AWS.

Serverless Video Clipper

Airport Gap

A Ruby on Rails application built to help developers and testers practice and improve their automated API testing skills on a real website.

Let's talk

Whether you want to schedule a call with me or have a question I can help with, send me a message and I'll get back to you in less than 24 hours.

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