rtyler

Defining the Real-time Data Platform

One of the harder parts about building new platform infrastructure at a company which has been around a while is figuring out exactly where to begin. At Scribd the company has built a good product and curated a large corpus of written content, but where next? As I alluded to in my previous post about the Platform Engineering organization, our “platform” components should help scale out, accelerate, or open up entirely new avenues of development. In this article, I want to describe one such project we have been working on and share some of the thought process behind its inception and prioritization: the Real-time Data Platform.

(sounds fancy huh?)

My first couple weeks at the company were intense. The idea of “Core Platform” was sketched out as a team “to scale apps and data” but that was about the extent of it. The task I took on was to learn as much as I could, as quickly as I could, in order to get the recruiting and hiring machine started. Basically, I needed to point Core Platform in a direction that was correct enough at a high level in order to know what skills my future colleagues should have. While I had tons of discussions and did plenty of reading, I almost feel sheepish to admit this, but much of our direction was heavily influenced by two conversations, both of which took less than an hour.

The first was with Kevin Perko (KP), the head of our Data Science team. His team interacts the most with our current data platform (HDFS, Spark, Hive, etc); in essence Data Science would be considered one of our customers. I asked some variant of “what’s wrong with the data infrastructure?” and KP unloaded what must have been months of pent up frustrations shared by his entire team. The themes that emerged were:

  • Developers don’t think about the consumers of the data. Garbage in, garbage out!
  • Many nightly tasks spend a lot of time performing unnecessary pre-processing of data.
  • The performance of the system is generally poor. Ad-hoc queries from data scientists, depending on the time of day, are competing with resources for automated tasks.
  • Everything has to be done in this nightly dependent graph of tasks, and when something goes wrong, it’s very manual to recover from errors and typically ruins somebody’s day.

Assuring KP that these were problems we would be solving, his next statement would become a mainstay of our relationship moving forward: “when will it be ready?

My second influential conversation was with Mike Lewis the head of Product. This conversation was quite simple and didn’t involve as much trauma counseling as the previous. I asked “what can’t you do today because of our technology limitations?” This is a good question to ask product teams every now and again. They frequently are optimising within their current constraints. One role of platform and infrastructure teams is to remove those constraints. We discussed the way in which users convert from passersby, to trial, to paid subscribers. He also highlighted the importance of our recommendations and search results in this funnel, and lamented the speed at which we can highlight relevant content to new users. The maxim goes: the faster a new user sees relevant and interesting content, the more likely they are to stick around.

Pattern matching between the current problems and the technology needed to enable new product initiatives I named and defined the high level objective for the Real-time Data Platform as follows:

To provide a streaming data platform for collecting and acting upon behavioral data in near real-time with the ultimate goal to enable day zero personalization in Scribd’s products.

In more concrete terms, the platform is a collection of cloud-based services (in AWS, more on that later) for ingesting, processing, and storing behavioral events from frontend, backend, and mobile clients. The scope of the Real-time Data Platform extends from event definition and schema, to the layout of events in persisted into long-term queryable storage, and the tooling which sits on top of that queryable storage.

As the nominal “product owner” for the effort, I aimed to describe less about what tools and technologies should be used, and instead forced myself to define tech-agnostic requirements. Thereby leaving the discovery work for the team I would ultimately hire.

The Real-time Data Platform must have:

  • A high, nearing 100% data SLA. Meaning we must design in such a way to reduce data loss or corruption at every point of the pipeline.
  • Maintain data provenance through the pipeline from data creation to usage. In essence, a Data Scientist should be able to easily track data from where it originated, and understand the transformative steps along the way.
  • Event streams should be considered API contracts, with schemas suggested or enforced when possible. A consumer from an event stream should be able to trust the quality of the events in that stream.
  • Data processing and transformation must happen as close to ingestion as possible. Events which arrive in long-term storage must be structured and partitioned for optimal query performance with zero or minimal post-processing required for most use-cases.
  • The platform must scale as the data volume grows without requiring significant redesign or rework.

In essence, we need to change a number of foundational ways in which we generate, transfer, and consider the data which Scribd uses. As Core Platform has unpeeled layer after layer of this onion, we have been able to affirm at each step of the way that we’re moving in the right direction, which is by itself quite exciting.

The design of the Real-time Data Platform which we’re currently building out is something I will share at a high level in a subsequent blog post.

I want to finish this one with some parting thoughts. If you are building anything foundational in a technology organization, you must talk to the product team. You must also talk to your customers, but I don’t like to ask them what they want, I like to ask what they don’t like and don’t want. Listen to that negative feedback, understand what lies beneath the frustrations. Finally, have a vision for the future, but build and deliver incrementally. When I first sketched this out, I was forthcoming in stating “this is a 2020 project.” I made sure to clarify that this did not mean we wouldn’t deliver anything to the business for 18 months. Instead, I made made sure to explain that to execute on this overall vision would be a long journey with milestones along the way.

If you haven’t ever watched a skyscraper being built, you would be amazed at how much of the time is spent digging a great big hole, sinking steel into bedrock, and pouring concrete. Months of people working in a city block-sized hole before anything takes shape that even resembles a skyscraper. Building strong foundations takes time, but that is in essence the role of any platform and infrastructure organization. The challenge is to keep the business moving forward today while also building those fundamental components upon which the business will stand in a year or two.

It is tough, but that’s exactly what I signed up for. :)