Hi, my name is
Diego Medina.
I like to build things.
I’m a senior software engineer specializing in architecting and building exceptional Rails applications. Currently, I’m focused on crafting scalable web services at Calendly.
About Me
Hi, I'm Diego!
I'm a web developer that specializes in Ruby on Rails and React applications. More recently also working with Node.js and Typescript.
I've worn many hats in web development. From building payment integrations, localizing a web application, built and maintained web extensions (Chrome and Firefox), architecting and breaking out microservices from a rails monolith, and now I'm helping lead the Trust and Safety Squad at Calendly.
When I'm not coding, I enjoy walking the Atlanta Beltline for some fresh air, playing board games with friends, or unwinding with a good book or a challenging logical puzzle.
Where I’ve Worked
Senior Full Stack Engineer @ Calendly
April 2017 - Present
- Lead engineer for the Notifications micro-service breakout. Designed architecture, documented implementation plan, and implemented key functionality.
- Jointly led the engineering efforts to address crucial database and latency issues.
- Co-developed an internal incident management bot for Slack, enhancing response times.
- Served as the go-to expert on DMARC, spam mitigation, internal solutions, translation processes, and incident management.
- Pioneered and co-managed browser extensions and add-ins for Chrome, Firefox, and Outlook, enhancing user experience.
- Contributed to diverse projects including Internationalization, Payments Integration, and One-off event types.
- Initiated and co-hosted bi-monthly internal Tech Talks, fostering a culture of knowledge sharing and continuous learning.
Some Things I’ve Done
Featured Project
Trust and Safety
I helped found and co-lead the Trust and Safety team, focusing on combating spam and abuse to create a secure environment for our users. My work involved building and scaling processes to address these challenges effectively.
- Web Risk
- Datadog
- PagerDuty
- DMARC
- Tableau
- EHawk
- Valimail
- reCAPTCHA
- OpenAI
- BigQuery
- Metabase
Featured Project
Innovation Expo Winner
I’m a five-time award winner at Calendly's Innovation Expo, recognized for delivering multiple impactful solutions that saved the company hundreds of thousands of dollars, enhanced customer protection, and improved operational efficiency. All of these projects were successfully built and implemented.
- Booking Abuse Protection
- SMS Capping
- Automate Disposable Domain Filtering
- Gmail Toolbar
- ML Abuse Mitigation
Featured Project
Notification Service
I led the architecture and development of one of Calendly's earliest and largest microservice extractions: the notification service. This Node.js microservice manages millions of SMS, emails, and push notifications each month.
Once built, the notification service unlocked numerous features, including:
- Speeding up deployment of notification-related code from potentially taking all day to deploying within 20 minutes.
- Capping SMS usage—-a feature I successfully advocated for—-which is projected to save the company over 1 million dollars annually.
- Providing seamless SMS support across various services.
- Enhancing observability and offering enterprise customers detailed insights into their notification usage.
- Node.js
- Typescript
- Faktory
- Prisma
- Redis
- Twilio
- Sendgrid
- Drizzle
Other Noteworthy Projects
Link Scanning and Interstitials
The Link Scanning and Interstitials project at Calendly was created to reduce the risk of our users interacting with phishing and malware in our platform by verifying that user-provided links that we store are safe
I led the creation of a new microservice using Ruby on Rails that sends API calls to Google WebRisk to check links.
Additionally, I added a new interstitial page where all customer-generated links are redirected. To make this work, I used Cloudflare Worker to send users from protected links to the interstitial page.
This project not only made our platform safer but also helped us prepare for future improvements and scalability.
AI Cannabis Content Detection
I led the design to use GPT as a second-layer to our term-matching detection system, which allowed us to increase our range of detection while lowering false positives for our cannabis SMS blocking functionality.
Calendly often experienced incidents with our SMS provider, Twilio, when one of our customers sent a text through our platform with cannabis-related content. These incidents can often result in filtering from carriers, blocked sender phone numbers, or even account suspension. Improving our ability to detect prohibited content in our SMS means that we can continue to provide a world-class text notification experience for our customers
DMARC Compliance
I played a key role in leading the DMARC initiative at Calendly from early-stage work to completion. I attended initial meetings with leadership from Valimail to discuss DMARC and identified the services that needed Valimail validation. I identified services that needed to be addressed and ensured all of them achieved DMARC compliance.
Throughout the project, I regularly checked Valimail for updates, provided progress updates to my squad, and conducted multiple product demos. I also informed the company about DMARC through five posts on the #general Slack channel, explaining upcoming changes and service deprecations.
I created new Confluence documentation, including a walkthrough video of Valimail, and conducted one-on-one training sessions with the IT team, occasionally answering their private questions. Additionally, I gave updates and demos during biweekly Product Demos and successfully handed off DMARC responsibility to the IT team.
But I remain the DMARC expert for the Trust and Safety squad, still fielding questions and concerns.