Microsoft Excel performs with greater care, speed, and visibility with ADX

Microsoft Excel, Microsoft’s spreadsheet service, is one of the most commonly used software products in the business world. It offers calculation and computation capabilities, graphing tools, pivot tables, and more. 

Microsoft releases new versions of Excel for the web almost every week for the millions of Microsoft 365 users who use Excel on their web browsers. “We’re offering a very complex code base to millions of users who are using the product in different ways,” says Einam Schonberg, Principal Software Engineering Manager at Microsoft. “Our challenge is to make sure that the new version is working properly.” Initially, the Excel team relied on other tools, including Splunk, to analyze software logs and test the new version. “Splunk didn’t work as well and was more expensive so we started looking for a new solution,” adds Schonberg.

Fixing issues faster

The Excel team then turned to Azure Data Explorer (ADX). Internally known as Kusto, the big data analytics cloud platform, and data exploration service is offered as Platform as a Service (PaaS) on the Microsoft Azure platform. Developed in 2014 by Microsoft’s research and development center as a grassroots incubation project, Kusto aimed to enable Azure users to quickly process and analyze telemetry analytics—meaning data collected at remote points. 

After migrating to ADX, the Excel team started releasing updates and diagnosing issues more accurately, frequently, and rapidly. “We do a process that we call rings of validation,” explains Schonberg. “Each new version goes to a small subset of users and only then does it start rolling out to growing audiences.” For every ring, the team relies on telemetry analytics from Kusto to verify the quality of the updates. 

The Kusto query language enables powerful and quicker processing. “Whenever there’s an issue, we can get immediate feedback on our queries and investigate the logs within seconds to make sure we’re delivering a consistently high-quality service,” describes Schonberg. “Our latency—or the delay between the event and its availability—improved from a day or a few hours to a few minutes. Our queries used to take minutes or even hours to run; now, they take mere seconds. We wouldn’t have been able to react to software issues as rapidly without Kusto.”  

Using Kusto, the Excel team can also combine customer feedback with service logs to gain more context and solve issues even faster. “Previously, we had to manually view user feedback and figure out which session they were referring to when they reported the issue,” explains Schonberg. “Now, we have a complete picture of what happened and can compare feedback to our data log and track similarities in events and timeframe.”

Empowered employees

Using ADX, the Excel team created internal dashboards for more visibility into every update. “We use these to track around 30 to 50 engineering metrics to make sure everything is running smoothly and can go over the information quickly in our weekly meetings,” says Schonberg. “We’re also getting insights about what our teammates are working on and how they’re contributing to each other, which gives us better visibility into our teamwork.” 

For the Excel team, Kusto quickly became a new favorite. “We educated our employees on how much faster, simpler, and more interactive Kusto is, making sure that every engineer and program manager felt comfortable using the service,” Schonberg says. In addition, the Kusto community at Microsoft also continually supports team members if they have any issues or questions. “We can ask questions about anything in the community or learn about new capabilities from the Kusto team,” says Schonberg.

“I’m delighted by the fact that Kusto is not just a language, it’s an entire ecosystem that keeps growing and evolving,” says Schonberg. “Today, ADX is tightly integrated with pretty much everything we do—how we run the service itself, how we run engineering, and how we ideate, test, iterate and develop new features. If the world runs on Excel, Excel runs on Kusto.”