trivago is the home to 500+ tech specialists from all corners of the globe – each with their own unique background and story of how they ended up here. Our trivago Tech Check-in series focuses on individual engineers' experience during their time at trivago. In this edition, you'll meet Mohammad Abed – a frontend software engineer who has been with trivago for 11 months now and is working on our Express Booking product.
In the middle of summer 2021, we hosted one of our favourite annual events of the year - trivago Tech Week! This year’s tech week had a new, hybrid format, featuring a wide variety of talks and exchange forums, hosted both by internal talents and external speakers. To make things even more engaging, the week included virtual opportunities for talents to gather and converse across departments, a gaming tournament and a highly anticipated live-music concert to tie everything together!
While engineering, we fix bugs, create new systems, build workflows and establish processes. Our job is to change things. Changing things can involve mistakes that ultimately lead to the failure of a particular system. To learn from these failures, a retrospective is helpful to get to the root of this problem. In the tech industry, a Blameless PostMortem is the right tool for this job.
When was the last time you booked accommodation without checking its photos? Most probably never! Because having imagery information makes our decision-making process much easier and faster. However, picking up the best possible images of a hotel to show to the user is an interesting problem to solve, because it can be a naive random selection or a sophisticated machine learning model to know what the user truly wants at that moment.
When operating applications in Kubernetes, proper lifecycle management is crucial to enable Kubernetes to manage applications correctly throughout their different phases: startup, runtime and shutdown. Improper or incomplete lifecycle management can lead to incidents with unforeseen and difficult to debug application behavior, such as random CrashLoopBackOffs, broken/zombie services not being restarted or even entire services not becoming healthy after a scheduled restart.
Five years ago trivago started to build guilds – small communities dedicated to certain topics or technologies – as a need arose to organize the collaboration of more than a hundred developers on a wide range of topics. You can read more about how we started in the previous blog posts Part I and Part II.
When techies hear about email marketing and designing HTML emails, they typically roll their eyes and think of a very boring field of work. In this article, we hopefully can explain to you why this is wrong from our perspective. Our team built a solution that our marketers use to easily design HTML emails with predefined modules within our email marketing platform Salesforce Email Studio, which is part of the Salesforce Marketing Cloud (SFMC). This article gives you an overview of our approach as well as why and how we built such predefined modules for Email Studio on our own.
This article presents how trivago's search backend team used reactive programming in Java effectively when designing and implementing one of our many Java backend services. Compared to traditional imperative and functional programming, reactive programming requires a mindset-shift in order to apply the concepts and techniques effectively. The benefits we gain support us in some key challenges that every engineer is facing with essentially every (micro-) service in today’s backend architectures: handling of blocking IO, backpressure, managing highly varying loads as well as message and error propagation.
In the trivago backend, we use the reactive programming pattern for fetching prices from advertisers and updating our caches. This helps us to increase the responsiveness (i.e., scalability and resilience) of our backend. Thus, our backend system can alleviate high response times from internal components and our advertisers while staying responsive, even if downstream components fail entirely. Here is how we use the Java library Reactor Core to ensure those guarantees:
After almost a decade, we decided to rebuild our in-house Business Intelligence web application to better support the organization. It is always challenging to replace software with a long history and a high degree of complexity. Nevertheless, we successfully completed the project because we fundamentally challenged and re-thought all aspects of the project.
COVID-19 has impacted the travel industry very severely. Even in these hard times, trivago remains committed to contributing to open source. As a tech company working on large-scale projects, we feel a responsibility towards supporting the open source community.
One of my favorite events throughout the year is the trivago tech get together. It's the one time where we all get together to celebrate tech. Here are some impressions from 2019:
Metrics are one of the main building blocks in the topic of observability.
Hence, we have a lot of metrics within our applications and especially for the connections between our applications. Every outgoing request has its latency measured and we also record the sizes of the request and the response. These numbers are collected in histograms and based on that data, in our Grafana graphs, we create corresponding graphs that show us e.g. the median size of request- and response payloads or the 99th percentile of call durations.
At trivago we are working heavily on the web platform and, based on the scale that we need to serve our users, our applications need to cater for many different kinds of environments and conditions.