#tech stacks

"Is there an actual human on here? Or is it all AI?" - My friend Sam

We are all part of the algorithm now. Resistance is futile.

Ready for a software product to be created? We can ensure a cost-effective and efficient development project by choosing the right technology stack.

There is so much that goes on behind the scenes when building a home. For various areas of the house, contractors use many construction materials. They primarily make use of concrete, treated wood, clay, and sand for the foundation. Fiberglass shingles, metals, or concrete tiles are also used for the roof as the first line of protection against heat and rain—also materials like recycled steel, wood, or brick and blocks to build beams and walls.

It’s time to upgrade your application development Tech Stack

Welcome to the fourth post from Tales of Timehop. This post is engineering focused and shares the language and tool decisions we made the past year during our first major growth spurt. This post was written by Benny Wong and originally posted on Underdog.io's blog. 

Happy new year! 2014 was a wild and exciting year at Timehop. Our backend team doubled in size but our user base grew by 17x! Our awesome friends over at Underdog.io interviewed us last week about Timehop's tech stack decisions which support this growth. We wanted to repost and share our secrets to stability. 

Describe Timehop in 2-3 sentences.

Timehop is your personal digital time capsule. We pull in your data from Facebook, Twitter, Instagram, iPhoto and other services and show you your memories from years past – kind of like a personal “This Day in History”. Our goal is to create a service that collects your history, captures your present, and makes it useful, meaningful, and accessible for you.

What are your primary programming languages?

Our main language on the backend is now Go. A year ago, we were mostly a Rails shop. Since then we’ve grown our daily active users about 17x. As you can imagine, a lot of things stopped working well and we needed to rewrite some systems to handle the growth. We tried a few languages and Go was the hands down winner for us. The main reasons we chose Go were for its incredible performance, sane concurrency constructs, and type safety. On the mobile app side, we have both iOS and Android. They’re both built natively: Objective-C on the iOS side, and Java on the Android side. Of note, both apps embrace functional reactive methodologies with ReactiveCocoa on iOS and RxJava on Android. It’s a mind bending experience to learn it, but eventually leads to a much cleaner and extensible app.

What are your primary web frameworks?

We’ve built a lightweight framework for timehop specific stuff (like authentication, API versioning, etc), but for the most part, we only use the Go standard HTTP library and gorilla mux for our API. In general, we’ve found the Go standard library to be an amazing set of tools. We don’t have much of a web presence as most of our traffic comes through our API, but for what we do have we use Rails.

What are your primary databases?

We use PostgreSQL, Redis, and DynamoDB. PostgreSQL is tried and true; Redis is amazingly fast and simple to use. But DynamoDB is our work horse. DynamoDB is an amazing product and I can’t imagine scaling without it. Our largest table in DynamoDB is pushing 63 TB and our average range query is about ~5ms. We chose Dynamo because it fit our workload perfectly. We are write heavy with a constant flow of writes as users sign up and we fetch their data. We are read light-ish as we currently look at only 1/365th of our data set on a given day. The ability to independently scale storage, read performance, and write performance was exactly what we needed.

Which DevOps tools do you use?

We use Cloudformation and Chef heavily. When we begin scaling we were a small and nimble team with no dedicated ops team so we tried to pick established tools with a solid community. We didn’t have much time to experiment or build a ton of tools, especially since we were focused on shipping a fast, fun, and stable app to our users. We just hired a DevOps engineer so this may change!

Which part of your stack are you most excited about?