May 2015 Summaries

Facing an influx of automated and fraudulent signups exploiting their free tier, a company implemented several strategies to combat the issue, including adding Google's Recaptcha to their signup flow, which initially reduced but did not eliminate fake accounts. When attackers shifted from using hotmail.com to gmail.com addresses, the company blacklisted the former and anonymous email signups, yet the problem persisted. Ultimately, they introduced an email confirmation step and leveraged Clearbit's data to verify email legitimacy, which proved more effective without impacting conversion rates. However, the company remains cautious about future tactics if attackers adapt by using valid email addresses, considering options like credit card authentication, phone number validation, or removing the free tier.

Versioning APIs is a challenging but essential task for companies offering public interfaces, as they must decide how to handle inevitable breaking changes. Clearbit, facing this challenge, has explored several approaches commonly used by other companies. One method is embedding a version number in the API URL, as practiced by Segment, which is simple but can become cumbersome with frequent updates. Another method involves specifying the version in the request header, a technique used by GitHub, which works well for infrequent changes. Stripe employs a more complex system using dynamic versioning based on the date of the first request, allowing flexibility in managing frequent changes and tracking customer usage. Clearbit has opted for Stripe's dynamic versioning approach, anticipating numerous future enhancements to their APIs.

A notable example of innovative API usage is demonstrated by Svbtle's registration process, which utilizes Clearbit's Person API. When a user enters their email in Svbtle's signup form, the API is called to retrieve information associated with that email, automatically populating additional form fields such as a user's bio and avatar. This method not only reduces friction in the signup process by autofilling fields that might not be in the browser's history but also enhances user experience by eliminating the need for manual input, such as uploading an image.