About John Kim

John Kim is the Chief Product Officer at Expedia. He is a seasoned and accomplished product and marketing executive with over 17 years experience as a digital media executive. John has a deep domain expertise in online and mobile search, local, advertising, analytics, gaming, and social media.

Customer Experience Q&A

This post originally appeared on Forrester’s blog on October 5, 2016. Content is shared below in it’s original form. 

Customer Experience Q&A with Scott Jones, VP, Global User Experience Design, Expedia Worldwide

In its early days, the online travel industry focused on speed, ease-of-use, and cost-effectiveness. That was a great start but it didn’t go far enough:  Travel is a complex and often daunting purchase decision — one layered with conflicting emotions like aspiration, excitement, and even fear. How has the industry evolved to deal with the emotional aspects of the travel experience?

Scott Jones is head of user experience design for online travel giant Expedia.  Scott will be one of our featured presenters at our CXSF 2016, October 20-21. In advance of the event, we sat down with Scott to explore some key aspects of his role and Expedia’s CX strategies.

How has Expedia evolved its user experience to address the complex multidimensional context of travel planning?

Jones: Several years ago, in the wake of a rapidly changing consumer tech landscape, we recognized the critical need to make heavy investments in new technology and intelligence to stay innovative, relevant and nimble.

Since then we implemented a “test-and-learn” approach, which allows our teams to propose an idea, build the hypothesis behind it and implement a small test to understand the customer response. This approach, coupled with our expanded user experience research capabilities, has allowed us to learn faster and better understand the “why” behind our customers’ behaviors.

We have also built an innovation research lab on our property to conduct tests directly with customers. Using eye-tracking and facial-movement technology, we can now measure what and where people look at and why. This allows us to get a more nuanced understanding of what customers want and how to move them from browsing to booking.

The goal of the research conducted at our innovation lab is not only to make our various sites and mobile apps more efficient and user friendly, but ultimately to increase confidence and delight, so our customers can focus on making their vacation fantasies a reality.

For many CX professionals, trying to quantify the emotional state of its customers at given moments in their journeys can seem like more art than science. How has Expedia attempted to quantify its customers’ emotions? What benchmarks do you use to track emotional engagement?

Jones: Our UX researchers regularly use electromyography (EMG) technology as we study customers using our products.

We place small sensors on the cheek and eyebrow of our test subjects and the sensors will record tiny changes in the user’s facial muscles.

Our researchers then track the changes in the EMG readings, similar to a graph on a lie detector test, to understand the real-time impact that the experience is having on the subject as he or she navigates our websites and apps.

Paired with eye-tracking and other more visual and verbal clues along with a Q&A, we get a sharp read on exactly where the user was looking and what s/he was doing. This allows us to detect subconscious changes in their response based on even minor changes to the experience.

Test subjects are so surprised at our ability to probe on these subconscious changes that they often joke, “it’s like we are reading their minds.” This information is then entered into a growing database, which is analyzed by our research and design teams to help us make better product development decisions.

Can you give us a specific example of a change in Expedia’s CX or UX that was driven by insights into the emotional context of your users’ travel experience?

Jones: One of the most interesting insights we’ve gathered is around decision-making.

Planning and shopping for a trip can be hard and nerve-wracking. The amount of options available for our customers can be overwhelming and the tradeoffs to balance can leave customers frustrated and even paralyzed.

We found that we could see tangible pleasure when customers could see the list of the hotels or flights they had been considering. “Yes, that one with the fantastic pool slide. I love that one.”

However, we didn’t expect to see such a spike of delight when they actually decided against a hotel. “No, that one isn’t close enough to the beach. Get rid of it.”

The act of deciding and deleting a choice moved them that much closer to booking the property they wanted and progressing further towards their trip.

This insight not only helped us develop our Scratchpad product, but also enabled us to understand just how we can improve the business by giving our customers the confidence they need to make more informed travel decisions.


To register or for more information on CXSF 2017, please visit the Forum website.

The Future Of Travel Looks Like Science Fiction


By Tony Donohoe, Chief Technology Officer and Senior Vice President of Technology at Expedia Inc.

Originally appeared on HuffingtonPost.co.uk

Just when I thought modern technology was hitting its peak, along comes virtual reality. VR is like something out of Blade Runner or Back to the Future – simply strap on a headset and open your eyes in a completely different world, without having to leave the one you’re in. It’s great for gamers and fun for thrill-seekers, but honestly? I think VR’s real potential lies in travel.

The days of relying on teletext for last minute deals are gone. From holiday inspiration to making a booking, the future of travel lies firmly online. But even this is changing.

I’ve spotted a trend: we don’t simply base our bookings on great deals anymore (though these do help!). Whilst at Expedia, I’ve noticed that more and more holidaymakers want to guarantee they’ll be getting an authentic experience: local produce, authentic digs and adventures they’ll never forget. Traditionally, this is nothing I couldn’t uncover without a good bit of internet trawling, but with the rise of virtual reality, I think I can go one step further.

Picture the scene: I can pop on a headset and stand on top of Iceland’s Gulfoss waterfall, or, perhaps, Peru’s Machu Picchu. I could even find myself wandering the bustling streets of an Asian city, where the tourist industry may or may not have taken away some of the local charm.

Fully immersive VR has the potential to captivate potential travellers with style and substance, offering true-to-life expectations and matching wearers to their ideal experience.

But what happens once I’ve found my dream break? It’s possible that hotels will take advantage of virtual reality technology, allowing holidaymakers to preview their accommodation. Exciting, yes, but still speculative. What’s really impressive is a nifty bit of technology that’s up and running right now: booking bot.

If, like me, you’re sick of spending hours searching the internet for your dream hotel, then worry not, booking bot does all the hard work. I begin a Facebook message to Expedia with a friendly ‘Hi’, input where I’d like to go, when and for how long, and in seconds, I’ll be shown the best deals. There’s little hassle and I could be making a cup of tea in the time it takes to chat.

Booking bot and VR both herald a new age of convenience. With the unavoidable airport check-in experience still lending an element of stress to proceedings, making what comes before and after as easy as possible will be key in the future. In fact, I wouldn’t be surprised if robots with suitcase-packing potential enter the mass market in years to come.

Once I arrive at my hotel (booked using booking bot), it’s only right that the seamless, space age experience continues.

“The modern traveller wants a friction-free, mobile-led experience that offers help when needed,” says Kevin May of Tnooz. Keyless hotel rooms, anyone? Mobile technology is bound to take over from something that’s so easy to lose.

Some experts are even going so far as to predict the fall of human interaction. Front desk staff replaced by holograms, waiting staff swapped for robotic butlers and smartphone apps: we could soon be living like The Jetsons, after all. Especially when you consider the potential of augmented reality.

You see, I haven’t only seen VR making waves: AR is coming to the fore as a holiday must-have, too. A certain game involving pocket-sized monsters has already shown that augmented reality can reach critical mass faster than VR, but travel-wise? I wouldn’t be surprised to see Google Glass-style specs replacing sunglasses in the near future. After all, I could look up at a landmark and be presented with overlaid fun facts, or browse a restaurant menu from my hotel room to help me decide whether to book.

Travel is changing, and the future may not be as far away as we’d first thought.

Exploring Artificial Intelligence via Natural Language Processing

Artificial Intelligence (AI) is a hot topic lately – it seems to be the main conversation starter at various industry events, workplace hallway interactions, and dinner parties. However, AI relies on the ability to interact successfully – or intelligently – with a consumer in some way. And in order to do that, you must have a robust system that understands what an input means.

In travel, these options are nearly endless. If someone says in casual conversation, “I want to go to Paris,” we make an assumption that they mean Paris, France instead of Paris, Illinois. Similarly, “Show me a flight on Friday” likely means for the next Friday on the calendar instead of one random Friday next month.

At the heart of this understanding is Natural Language Processing (NLP) or the task of turning travelers’ common questions, those they would ask a friend or travel agent, into searchable content. We’ve been experimenting with NLP for the past few years; ever since we realized that the standard travel search framework doesn’t work as well on mobile devices. For example, did you know that a search request for a big city like London can turn up thousands of hotel results? Going through that information on a desktop can be challenging, but someone searching on a tablet or a mobile phone is unlikely to scroll through every page of those results. And with wearables exploding on the market, you can image the quantity of acceptable results becomes even smaller.

Filters become a very important part of slicing search data into relevant, digestible chunks of information that you care about. With mobile devices, finding an easy way to input those filters is a key priority. Selecting filters manually is an option, which is why we offer solutions like that on our mobile app and mobile websites. But the appeal of voice- and chat-bots is they take some of that filtering away by having a more fluid conversation with customers. Instead of checking a box that says, “pet friendly” you could tell a chat bot you want to bring your dog, and it can narrow results to those that accept pets.

Experiments available today

In addition to the mounds of traveler data we look at en masse to predict trends and identify patterns, we are testing ways NLP can expedite the search process. Some of this happens on the backend of our site via machine learning and automation of certain big data tasks. But others are more obvious and available for direct interaction:

  • Search Anything on our Homepage: As the name implies, you can type an array of travel-related requests into this field and we’ll begin to filter your search results for you automatically. This space has been interesting to watch, as it has helped us understand some of the more common requests associated with search. For example, we have implemented a breakfast filter because of content frequently being searched for in this field.

Search Anything

  • Expedia tablet app: If you’ve downloaded our Expedia app on an iOS or Android tablet, you’ll notice the interface is a lot different from our desktop experience and mobile phone app. The most obvious difference is upon opening the app, you’ll see just one search bar. Similar to the Search Anything box, it is designed to allow customers to enter NLP travel requests. This was a huge learning for us – we saw customers inputting restaurant names and popular destinations such as the Eiffel Tower, and quickly had to adjust our prompts to encourage visitors to enter questions we could answer.

Expedia Tablet App

  • Hotel Smart Finder on Mobile Web: Launched just a few weeks ago, travelers who use our mobile hotel search product will be presented with an open search box. With this feature travelers can look for hotels using specific hotel names, hotel locations and neighborhood, hotel amenities such as wifi and restaurants, or simply for specific outcomes such as family friendly. We’ve already seen travelers search for a range of things like “all inclusive,” “on the beach,” or “hot tub.”

Hotel Smart Finder on Mobile Web

  • Expedia bot for Facebook Messenger: Our most recent addition to our NLP research world. Just launched today, customers using Facebook Messenger can interact with an Expedia bot to fulfill hotel search requests. The bot operates on a structured conversation flow: it analyzes information provided and prompts the user to input other relevant data points to complete a search.


Tip of the iceberg

The beauty of our work to date is that there’s still plenty to investigate in this space. Voice recognition software continues to advance, which makes the possibilities of voice-activated search more prevalent. Messaging solutions around the world are growing at an impressive rate compared to other types of technologies, and the demand for these platforms to facilitate commerce is also increasing. For example, in China, people already use the messaging app WeChat to order an array of services like requesting taxis or booking a doctor’s appointment.

And NLP isn’t the only thing we’re working on. Machine learning is a big investment area for Expedia as well. It is what powers our flight search algorithm – Best Fare Search – which is a one-of-a-kind program that reduces the nearly infinite set of flight combinations down to a key set of realistic and reviewable options. This algorithm, like many others on our site, has been learning patterns for over ten years.

As the data available grows, so will our ability to refine the algorithms that can turn this content from natural language processing to a solution that more closely resembles artificial intelligence. We have a team of data scientists around the globe closely monitoring our progress and making tweaks as we notice unique findings in the data. As our tools become more sophisticated, they can tap into more computer power and better analyze the fascinating patterns buried in the mounds of data. Our data scientists review this content and apply learnings to our products, resulting in a better experience for our travelers.

Expedia has been looking at travel data for the last 20 years. Through our scale, our vast partnerships, and our loyal customer base, we have access to better travel insights than anyone else in the industry. But access to the data isn’t enough anymore. We are testing, learning, and applying our insights to our products on a daily basis. We believe this passion towards making our sites better every day is what will put us ahead, particularly in emerging areas like using machine learning, natural language processing, and artificial intelligence, to make travel a personalized experience.

– David Fleischman, Vice President of Global Product



4 Ideas to Apply to Life, Leadership and Technology


We believe great products are built by great teams. But establishing a great team can be challenging, especially when your team includes thousands of people and spans across three functional areas, four externally facing brands and five continents.

As part of our roles at Expedia, we often are asked, “What is your vision for Expedia and how do you motivate everyone to build your vision?” People are often surprised by our answer, “we don’t.” Consumers are too unpredictable, the industry is changing too fast and investing in one vision is too restrictive. Although we’re acutely aware of new trends and always watching for new concepts to test, we can’t predict the future nor do we want to pretend we can. Our teams want to contribute their own intellect, talents and efforts to the future of Expedia. They want meaningful problems to solve and they don’t want their leaders to give them precise, especially falsely precise, answers.

That said, we need to provide direction so our teams can make their own autonomous decisions on a daily basis. So how do we motivate our teams to act as one cohesive group and, at the same time, challenge them to continuously improve and set new benchmarks for performance?

For us, this is all about our APPROACH.

Aman and I are vastly different people. We grew up in different cultures. We were raised on different continents. We have had fairly distinct life experiences.  Our resumes have almost nothing in common. Yet, when it comes to the type of culture we want to build, we both want the same thing – a culture rich in debate, a hunger to learn and a drive for excellence. We want our teams to love the work as much as we do. Our approach can be described using four basic but powerful principles – applied to not only our jobs, but also to our personal selves.

Principle 1: Be scientific.

Get close to a problem, make observations, build and test a hypothesis, and follow the data. Then do it all again. This removes unintentional bias towards one solution or another and instead prioritizes data. If we are consistently scientific, and move and test and fail and learn quickly, we can iterate ourselves towards breakthrough.

Utilizing the scientific method has expedited our testing capabilities and changed our approach across the company. From branding to SEO to mobile product to our cloud solution teams, each group is implementing tests of varying sizes to understand what resonates with travelers and why.

Principle 2: Make it easy.

Life is complex. Complexity can make travelers afraid. Travelers frequently visit new places and are uncertain about what they will experience when they land or walk into a hotel or go on an excursion. We must make planning, booking, and enjoying travel as easy as possible to be successful.

It sounds counter intuitive, but we know that taking a vacation can be stressful. Our mutual responsibility is to make this process simple for travelers. Planning should be inspiring. Booking should be straightforward and instill a traveler with a sense of confidence that she found the best trip at the best price available. Enjoying a trip should be as simple as arriving and having clear guidance for what’s next – whether it’s lounging by a poolside bar, hiking a nearby trail, or exploring the local history.

Principle 3: Don’t be boring.

The world is distracted. We are competing for time among consumers. The internet used to be about relevancy, but relevancy is now table stakes. In order to succeed, you must be interesting.

We’ve entered an era where teens will have spent more time playing online games than they’ve spent in a classroom. In fact, there’s a recent trend evolving where teens are delaying getting their license – in favor of texting. This may sound silly, but when thinking about a group of teenagers loading into a car, they are all on their phones and connecting with others, whereas the person driving is out of the loop. This emphasis on content means companies are competing for attention. In that world, the most interesting information wins.

Principle 4: Be better every single day.

Make incremental changes. It’s hard to remember how you did something last year, but you can easily remember how you did something yesterday. So improve upon it. Learning is your friend and failing is your friend – both teach you things. You can do some really big things with small changes.

This applies to not only your personal being, but also the elements you interact with or work on every day. Being a better manager, building a slightly better product, driving with a bit more respect. These simple changes create a significant impact over time.

These principles have become our religion at Expedia: they are the mantras we echo in team meetings, in product review cycles, and with our partners. We’ve found they lead to better products, better efficiency, better job satisfaction, and a better life.


John and Aman first presented these guiding principles during Expedia’s Partner Conference in December 2014. This blog also appears on A Plus

Travel Search Reimagined: Meet the New Expedia Tablet App

By John Kim and Aman Bhutani

The status quo of searching for travel products is unnatural. And it’s getting harder. Today, with the release of our new Expedia App for iPad and Android tablets, we’re changing the way people will discover, plan and book trips on tablet devices.

Here at Expedia, we study the travel planning process carefully. To start, potential travelers search four to five different destinations in a given session. They’ll then search for photos and possible activities. After they’ve settled on a destination, they’ll search for flights and hotels and possibly car and ground transportation. This process is cumbersome because each phase requires so many steps. Looking for flights alone can take up to 48 searches before consumers find one they’re happy with.

As we started thinking about the new tablet experience, we wanted to build a product that complemented how users engaged with tablets and set out to make our app the starting point for travel inspiration. We wanted to build an experience that was aligned with how users think about their trips holistically while giving them the power tools (like filters) that they’ve come to grow and love on desktop.

Despite technological advances, travel planning has become increasingly difficult. Customers are conducting more searches across more devices and not getting to their destination (or booking) any faster. Rather than force users down a specific path to look at hotels or flights separately, we wanted to provide them with a more holistic way of planning their trip.

We believe that people are ready to discover and experience travel in a more connected way. Let’s take a closer look at the two big bets we’ve made in creating an easier — and better — way to explore and book travel.

Single Search
Expedia Tablet App - Android

The tablet is inherently a browsing device. It is as much about entertainment as it is about utility. With that in mind, we wanted to build an experience that allows users to begin exploring as quickly as possible.

Most travel sites and apps today, however, require a lot of information before a search can even be processed. Where do you want to go? When do you want to go? Are others traveling with you? Do you want to look at just flights, just hotels or both hotels and flights?

For the mindset of a person on the couch, this barrage of questions is intimidating. Our solution to this problem? A single search box.

Upon first interaction with our app, the experience should be super easy, starting with our launch screen. To optimize for mobile exploration, we removed all the upfront questions that users typically need to answer. By limiting the questions to just one, we believe it is easier to jump right in so they can quickly begin browsing.

For those who want more inspiration, we also feature travel collections with a wide variety of recommendations based on different interests and seasonality.

Federated Search
new tablet app flight and hotel search results side by side

Nearly every single travel site today forces users down a linear path to purchase individual components of a trip. With federated search, we’re aiming to bring users back to one focal point — the trip, not its parts.

The process of shopping for flights and hotels is the most time consuming and least fun part of planning a vacation. Consumers want to be inspired and engaged, not forced to fill out a questionnaire and be subsequently overwhelmed by endless pages of results.

As most customers on tablets are in the research phase of their trip planning, the ability to see flights and hotels side by side is more conducive to exploring options. While some locations may boast cheap hotels, flying there may be costly or vice versa.

By displaying these results together, we’re helping travelers realize unexpected information to aid them in choosing where they go. The ability to see prices across destinations is a prime example of why combined flight and hotel search is helpful, particularly in a tablet experience.

This type of experience is not ready for desktop. Because hotel search results generate more quickly, consumers would notice a delay in flight results on desktop when done side by side. However, because the tablet app is built on a different layer of software than websites, we can make the wait time feel minimal. With tablet, we have the opportunity to attack problems that we can’t on desktop sites.

Our Vision: Make It Simple
Regardless of whether you’re exploring or booking, we hope you enjoy your experience with our new app. We’ve made a concerted effort in bringing a trip back together in a more natural and beautiful way.

By implementing features that no one else in the industry is yet doing, our hope is that our app is something you’ll want to invest your time in beyond just making flight and hotel reservations.

We’re on a mission to transform Expedia, whether it’s on our site or with our apps, into a place where users can start their travel planning or discover the trip they want to take. Tablet is our first step forward in achieving this goal.

Our new tablet app is now available in the App Store and in Google Play. We welcome you to check it out and let us know what you think.

LAUNCH Festival Hackathon

A few months ago, I had the privilege of being one of the judges at the LAUNCH Hackathon hosted by Expedia, CapitalOne Labs, and BitPay. Over 800 developers and designers participated and over $2 million in prizes were given away. In addition to the grand prizes for best overall product (a $100,000 investment from the LAUNCH Fund), Expedia was a premier sponsor, giving away prizes to the top 5 teams who used our API in an interesting way.

It was an invigorating experience and I was blown away with what the teams were able to pull together in under 48 hours as well as with the great ideas on ways we could extend Expedia’s API in the future.

This hackathon solidified my belief that there hasn’t been a more exciting time to be in the travel and technology space. Here are some highlights from the whirlwind weekend:

LAUNCH Hackathon

LAUNCH Hackathon

LAUNCH Hackathon

Expedia API Winners
For the teams who used the Expedia API most creatively, Expedia travel credit was awarded:

  • $5,000 for 1st
  • $2,000 for 2nd
  • $1,000 each for 3rd, 4th and 5th

LAUNCH Hackathon

First Place: Oasis
The Oasis team used our Points of Interest API to build an exciting app in the discovery space. The app recommends points of interest to visit on a road trip. If a traveler accepts or ignores this feedback, it is used to improve suggestions for future travellers. We found the app to be creative, fun, and an excellent use of our API!

Second Place: Serendipit.us
Serendipit.us tied Facebook and travel itineraries together to let travelers meet up with other people who were traveling to the same destination as you during overlapping days. We thought it was an interesting take on integrating social and travel.

Third Place: DreamCatchr
DreamCatchr was a Chrome plugin that linked hotel searches to images with location data in Pinterest. We thought their visual design was beautiful and liked the idea of enhancing existing sources of emotive location photography.

Fourth Place: Noteary
Noteary built peer-to-peer marketplace for Evernote notes. The imagined use cases included class notes in college or conference notes for attendees. They implemented a “notes near me” feature, but then also added support for pulling in your Expedia itinerary list and letting you see notes for places you were going to be in the future as well. We liked the creative use of an undocumented API, and the fact that they gave us a use case for extending our itinerary API to third parties in the future.

Fifth Place: TravelNanny
Travel Nanny built a mobile app to augment your itinerary with information you might need. They used a third party API to parse your itinerary, then added additional information like what visas you need for the trip. We liked that they were solving a real problem for a lot of our customers and it made us interested to find out more about the visa information service they were consuming.

Best Overall Product
For the competitors for best overall product, three grand prize winners were chosen from a group of top five finalists. The honor was bestowed on VUE, Blush, and Ripple, all of whom received a $33,000 investment prize from The LAUNCH Fund.

1st Place: VUE
Vue automatically tracks all users interactions on mobile applications, provides a powerful search engine to learn more about your users, and allows you to ask questions to specific users about their in app behavior.

2nd Place: Blush
Received a bonus prize of $25,000 from Barracuda Ventures
Blush is a unique twist on 1-1 messaging with the people who matter the most to you. Blush is a mobile app that combines the convenience of offline texting with the intimacy of real-time video. Using the front-facing camera, a video is recorded on your recipient’s phone as your message is revealed one word at a time. When done, the video is sent back to you automatically so you can watch and share in the moment.

3rd Place: Ripple
Ripple lets you share content from your phone to users near you, where they have the choice to continue spreading the content themselves. It’s the new, democratic way to share ideas with people nearby.

We loved being at LAUNCH and getting our creative juices flowing. The community blew us away with their passion. In the future, we’ll highlight and take a closer look at some of the winning apps. Stay tuned!

A Technical Look: How Expedia is Simplifying Travel Planning

By John Kim & Aman Bhutani

In the last four years, the average number of flight searches a customer makes per booking has grown from 15 to 48. 15 to 48! Isn’t that crazy?! Do you remember the last time you searched for a flight or hotel? How many searches did you do? Did you remember the results of all your searches? How about even two or three searches?

In our lab, we’ve noticed that people can barely remember the searches they’ve performed or the results that they’ve seen. What we’ve also noticed is despite technological advances, many people still opt for good old pen and paper to help them determine the best travel choices.

In an age where you want to search and book at any point in time on any device, taking physical notes seems impractical. By the time you write things down and share the information with your travel companions, all that information has probably changed and all your hard work has gone down the drain.

Here at Expedia, we’ve developed technology to solve this. The time has finally come to ditch the pen and paper.

Meet Expedia’s Scratchpad.

With Scratchpad, we’ve eliminated the need for you to take handwritten notes. Scratchpad allows you to return instantly to the hotels, flights, and packages you looked at before, with the same dates you used during your last search and the most current price.

Scratchpad records everything for you so you don’t need to jot anything down. Much like your handwritten notes, you can keep what you want and delete information you no longer need. The power is in your hands. And the best part? We keep all this information up-to-date for you.

Scratchpad makes it easier to search across devices too: start your search on your laptop during lunch break, continue it on the Expedia app on your smartphone on the subway ride home, and then review options with your travel partner on your tablet later that night.

This new feature is already live on our site. Check it out and let us know what you think. We already have more ideas on how to make Scratchpad even better, but we’re always hungry for feedback. We’re so excited to continue developing features that the world has never seen before.


Warning: We’re about to get our geek on below. Continue reading at your own risk.

At Expedia, speed and scale are of the essence so we implemented the note-taking functionality inside Amazon EC2. Whenever a user conducts a search, a brief message is sent to our cloud-based User Interaction Service. We also used Apache Thrift as a lightweight (and, so far, flexible) format to encode and transmit those messages. Our goal is to preserve backward compatibility as the message format evolves, something that Thrift has done well so far.

The User Interaction Service is a simple broker. Its job is to inspect messages and hand them off to a variety of consumers, each of which can write the details of that message into a different place in the collection of data stores. The relationships between this data, between users, the searches they do, the hotels and flights and cars they look at, and the things they eventually buy, make up an enormous network of nodes that we call the Travel Graph.

User Interaction Service


Rather than build a traditional relational database schema that encompasses everything, we’ve built the Travel Graph as a collection of special-purpose data stores. A good example of this is the note-taking system that records your shopping on the site, which is a simple sharded MongoDB cluster that scales well (with a few caveats).

Today we’re recording about 100 notes per second for all our users combined, for around 200GB of data overall. We expect that figure to increase by one or two orders of magnitude as we keep track of more things and rollout worldwide. Other special-purpose systems help us aggregate and trend that data, so that we can show shoppers what the travel marketplace looks like in real time.

The data that results from users shopping on Expedia should ultimately be an integrated part of the entire shopping experience and not just limited to the Scratchpad page itself. As a result, the Travel Graph service layer collects data from the various data stores, and returns it back to our site servers.

We’ll break down individual pieces of this architecture in subsequent posts, with comments from the development teams that have built them, and focus on practical implementation. In the meantime, keep watching the site—we’re releasing new Scratchpad features quickly, and would love to know what you think.


Under the Hood: Improving Flight Search at Expedia

By John Kim & Aman Bhutani

In this blog, we’re taking a look under the hood at Expedia. A closer inspection of our travel engines will reveal the millions of calculations and computations being made every millisecond so travelers everywhere can quickly and easily book a great vacation. It is here that we’ll share more about how we are developing smarter solutions and recommendations to guide our customers to the trip they want to book. Welcome.

Most people begin planning their trips with flights. We’ll start there too.

A typical customer searches for a flight up to an average of 48 times before booking. Here at Expedia, we strive to bring that number down by surfacing the most relevant results that can include alternative surrounding airports, day, or time of travel.

For a given round trip flight search between two destinations, there can be billions of flight combinations, even when only looking at a single departure and return date. Expedia whittles that down, returning the best sixteen hundred results in the form of 40 departing and 40 returning flights.

Yet as every traveler knows, each search begs more questions than it answers. Is the best flight for you flying out of different airports? Would adjusting the length of your stay or departure day save you any money?

Take a basic flight search: Seattle to Miami for a five to seven day trip. To find the cheapest round trip fare in a 30-day period, you could conduct 3 searches (a search for a 5-, 6- or 7-day trip) for each day in that period, which would quickly get you to 90 searches.

Now, imagine you had the inside knowledge that traveling to Fort Lauderdale is a great alternative to Miami, suddenly you find yourself having to do another 90 searches to find the best prices. Now combine those airports and you have 180 combinations. Adding other departure or arrival airports such as Portland or Palm Beach pushes the number over 500.

With an average search taking at least a minute, doing all this research would take you hours. With thousands of price updates taking place every hour, you’ll have to start again by the time you finish since the prices and availability will have changed. It’s no wonder why people end up searching 48 times!

Meet Expedia’s New Flight Recommendations

By leveraging the over three billion flight searches performed worldwide on Expedia, Flight Recommendations looks for patterns to help travelers with their next search.

In fact, we see our users follow very distinct habits. To start, travelers look to depart and return on specific days, such as leaving on Sunday and returning on Friday. They will then search leaving Saturday or returning on Thursday, all in hopes of finding a more convenient or cheaper fare. Combine this with searches for alternate airports and suddenly travelers find themselves overwhelmed with all the possibilities.

By following the patterns of how our travelers search, then book, and finding alternative airports/dates in those searches, Flight Recommendations surfaces the best options. We look for similar deltas for departure and arrival days and surface them as search recommendations. Our goal is to make it easy to see all the best options at a glance so travelers can choose what’s right for them whether it’s price or convenience.

Recommending alternate flights to travelers isn’t new. You’ve probably seen this in the form of fare calendars. However, this system doesn’t help travelers with anything beyond a snapshot of a saved price. Our team is looking at real purchasing patterns, of real travelers at scale so we can help you find desirable, bookable flights for less.

With each recommendation, we track the effectiveness, value, and accuracy of the prediction against real booking information and adjust them to best benefit our customers. These adjustments could take the form of different data, adjusted thresholds, or additional factors. The algorithm is always evolving and is the backbone of the recommendations feature.

Going on vacation is fun. Planning a vacation, however, is a multivariate optimization problem that some of the smartest engineering minds are working on. Together, we can advance the science of travel to help consumers save time and money. The opportunities we have to identify patterns with our data are endless and we are just barely scratching the surface. Stay tuned!