This the second post in a two-part series. In the first part of the series, we discussed the different aspects of load shedding and why it matters to think of it as part of the design of web services. We recommend reading it first as it sets the context for…

Load shedding is a design pattern used by high performance web services to detect and fail gracefully when there is traffic congestion. …

Running Clojure tests in Leiningen projects is fairly simple for most use-cases. For a few out-of-the-ordinary use-cases, however, it can become surprisingly difficult to control. In this post, we look at how to write Leiningen test selectors that go beyond simple use-cases. The Pivotal Role of Test Selectors in Continuous Delivery Test selectors can be thought of as a…

One of the strengths of Clojure is the ability to interoperate with and harness the power of the JVM. But this interoperability comes with its baggage. For one, we can never really ignore the JVM — things like class loading, garbage collection, byte code interpreter, JIT compiler— for another, we…

At Helpshift, we have come to write two kinds of tests for our systems: Unit tests: Tests that do not need to query any external system and can run blazingly fast, and run on a per-commit basis. Integration tests: Tests that query databases and other systems and take longer than…

In a language like Clojure, it is very easy to move fast and develop new features. That is one of the many reasons we have been using Clojure at Helpshift for almost ten years. As a consequence of the number of features that we were shipping, we were also adding…

Introduction In this post, we look at Helpshift’s journey of moving to a sharded model of data. We will look at the challenges we faced on the way and how Scylla emerged as our choice of database for the scale that Helpshift 2.0 is aiming to serve (over 30K/s). Before we…

The Helpshift dashboard provides the ability to search through the issues/tickets reported by users. Users can search for anything by using a query language, which gets transformed into an Elasticsearch query. Another important aspect of our search engine is to show suggestions to the user while the user is building…