Back-end Posts

The Toptal Engineering Blog is a hub for in-depth development tutorials and new technology announcements created by professional software engineers in the Toptal network.
Joaquin Cid
Angular 6 Tutorial: New Features with New Power

Angular 6 is out! The most outstanding changes are in its CLI and how services get injected. In this tutorial, Toptal Freelance Angular Developer Joaquin Cid goes over the basic steps of initial setup and then creates a small diary app using Material Design for the front end and Firebase for the back end.

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Amaury Martiny
One-click Login with Blockchain: A MetaMask Tutorial

Online users are becoming increasingly resistant to traditional email/password registration processes. One-click social logins via Facebook, Google, or GitHub are better, but they come with data privacy trade-offs.

This article introduces a one-click, cryptographically-secure login flow using MetaMask, with all data stored on the app’s own back-end.

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Brad Peabody
Server-side I/O Performance: Node vs. PHP vs. Java vs. Go

Understanding the Input/Output (I/O) model of your application can mean the difference between an application that deals with the load it is subjected to, and one that crumples in the face of real-world uses cases. Perhaps while your application is small and does not serve high loads, it may matter far less. But as your application’s traffic load increases, working with the wrong I/O model can get you into a world of hurt.

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Nermin Hajdarbegovic
ARM Servers: Mobile CPU Architecture For Datacentres?

Boring. That’s a word many people use to describe the server industry, although unexciting and uneventful would be a better fit. This is not necessarily a bad thing, because when something “exciting” happens to a server, it usually involves blue smoke and downtime. Luckily, the server space is about to get a bit more exciting, thanks to the introduction of servers based on ARM processors.

In this post, Toptal Technical Editor and resident chip geek Nermin Hajdarbegovic explains why ARM processors could end up powering a server near you, and what this means for the software industry. The potential implications of ARM servers are huge, but there is no cause for alarm. This industry segment does not tend to evolve fast, and developers will have plenty of time to get ready.

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Leandro Lima
Building a Rest API with the Bottle Framework

REST APIs have become a common way to establish an interface between web back-ends and front-ends, and between different web services. The simplicity of this kind of interface, and the ubiquitous support of the HTTP and HTTPS protocols across different networks and frameworks, makes it an easy choice when considering interoperability issues.

Bottle is a minimalist Python web framework. It is lightweight, fast, and easy to use, and is well-suited to building RESTful services. In this article, I’ll provide a walkthrough of how to build a RESTful API service using Bottle.

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Carlos Ramirez III
How to Use Rails Helpers: A Bootstrap Carousel Demonstration

One of the most misused, misunderstood, and neglected of all the Rails built-in structures is the view helper. Helpers often get a bad reputation for being a dumping ground for one-off methods used across the entire application’s view layer. But what if your helpers could be more semantic, better organized, and even reusable across projects? What if they could be more than just one-off functions sprinkled throughout the view, but powerful methods that generated complex markup with ease leaving your views free of conditional logic and code?

Let’s see how to do this when building an image carousel, with the familiar Twitter Bootstrap framework and some good old-fashioned object-oriented programming.

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Sripal Reddy Vindyala
How to Tune Microsoft SQL Server for Performance

To retain its users, any application or website must run fast. For mission critical environments, a couple of milliseconds delay in getting information might create big problems. As database sizes grow day by day, we need to fetch data as fast as possible, and write the data back into the database as fast as possible. To make sure all operations are executing smoothly, we have to tune Microsoft SQL Server for performance.

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Pavel Tiunov
Application Development with Rapid Application Development Framework AllcountJS

AllcountJS is an emerging open source framework built with rapid application development in mind. It is based on the idea of declarative application development using JSON-like configuration code that describes the structure and behavior of the application.

In this article, we walk through a step-by-step tutorial for prototyping a data oriented web application using AllcountJS.

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Mikhail Selivanov
Buggy Java Code: The Top 10 Most Common Mistakes That Java Developers Make

Java, a sophisticated programming language, has been dominating a number of ecosystems for quite a while. Portability, automated garbage collection, and its gentle learning curve are some of the things that make it a great choice in software development. However, like any other programming language, it is still susceptible to developer mistakes.

This article explores the top 10 common mistakes Java developers make and some ways of avoiding them.

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Lê Anh Quân
Advanced Java Class Tutorial: A Guide to Class Reloading

In Java development, a typical workflow involves restarting the server with every class change, and no one complains about it. But is Java class reloading that difficult to achieve? And could that problem be both challenging and exciting to solve? In this article, I will try to address the problem, help you gain all the benefits of on-the-fly class reloading, and boost your productivity immensely.

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Nikolay Derkach
A Tutorial for Reverse Engineering Your Software's Private API: Hacking Your Couch

Reverse engineering and hacking are usually related to malicious activities that result in sleepless nights of engineers responsible for system maintenance.

Reverse engineering is a tool that we can utilize to find the flaws and improve our software in many aspects. This article shows us how to use these techniques to learn more about different implementations of web API.

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Ahmed AbdelHalim
The Publish-Subscribe Pattern on Rails: An Implementation Tutorial

The publish-subscribe pattern] (or pub/sub, for short) is a messaging pattern where senders of messages (publishers), do not program the messages to be sent directly to specific receivers (subscribers). Instead, the programmer “publishes” messages (events), without any knowledge of any subscribers there may be.

This article provides insight in how to use the pub/sub pattern, in Rails, to communicate messages between different system components without these components knowing anything about each other’s identity.

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Balint Erdi
JavaScript Promises: A Tutorial with Examples

Promises are a hot topic in JavaScript, and you should definitely get acquainted with them. They are not easy to wrap your head around, it can take a few articles, and a decent amount of practice to comprehend them. Aim of this article is to help you understand Promises, and nudge you to get more practice using them.

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Demir Selmanovic
The 10 Most Common Mistakes Web Developers Make: A Tutorial for Developers

Today we have thousands of digital and printed resources that provide step-by-step instructions about developing all kinds of different web applications. Development environments are “smart” enough to catch and fix many mistakes that early developers battled with regularly. There are even many different development platforms that easily turn simple static HTML pages into highly interactive applications.

All of these development patterns, practices, and platforms share common ground, and they are all prone to similar mistakes caused by the very nature of web applications.

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Ilya Sanosyan
Buggy PHP Code: The 10 Most Common Mistakes PHP Developers Make

PHP makes it relatively easy to build a web-based system, which is much of the reason for its popularity. But its ease of use notwithstanding, PHP has evolved into quite a sophisticated language, with many nuances and subtleties that can bite developers, leading to hours of hair-pulling debugging. This article highlights ten of the more common mistakes that PHP developers need to beware of.

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Ryan Wilcox
The Many Interpreters and Runtimes of the Ruby Programming Language

Which Ruby implementation is right for your project? While the reference implementation (Ruby MRI) remains the interpreter of choice, an alternate Ruby implementation may be right for your project, depending on your operational goals and constraints.

This article showcases the Ruby interpreter implementations and runtimes available today, discussing the advantages and disadvantages of each.

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Martin Chikilian
Buggy Python Code: The 10 Most Common Mistakes That Python Developers Make

Python’s simple, easy-to-learn syntax can mislead Python developers – especially those who are newer to the language – into missing some of its subtleties and underestimating the power of the language.

In this article, Toptal’s Martin Chikilian presents a “top 10” list of somewhat subtle, harder-to-catch mistakes that can trip up even the most advanced Python developer.

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Arkadiy Zabazhanov
Elasticsearch for Ruby on Rails: A Tutorial to the Chewy Gem

Elasticsearch provides a powerful, scalable tool for indexing and querying massive amounts of structured data, built on top of the Apache Lucene library.

Building on the foundation of Elasticsearch and the Elasticsearch-Ruby client, we’ve developed and released our own improvement (and simplification) of the Elasticsearch application search architecture that also provides tighter integration with Rails. We’ve packaged it as a Ruby gem named Chewy.

This post discusses how we accomplished this, including the technical obstacles that emerged during implementation.

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Naftuli Kay
An Introduction to Mocking in Python

More often than not, the software we write directly interacts with what we would label as “dirty” services. In layman’s terms: services that are crucial to our application, but whose interactions have intended but undesired side-effects—that is, undesired in the context of an autonomous test run.

For example: perhaps we’re writing a social app and want to test out our new ‘Post to Facebook feature’, but don’t want to actually post to Facebook every time we run our test suite.

The Python unittest library includes a subpackage named unittest.mock—or if you declare it as a dependency, simply mock—which provides extremely powerful and useful means by which to mock and stub out these undesired side-effects.

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Jose Ferreirade Souza Filho
Hunting Java Memory Leaks

Inexperienced programmers often think that Java’s automatic garbage collection frees them from the burden of memory management. This is a common misperception: while the garbage collector does its best, it’s entirely possible for even the best programmer to fall prey to crippling memory leaks.

In this post, I’ll explain how and why memory leaks occur in Java and outline an approach for detecting such leaks with the help of a visual interface.

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Krešimir Bojčić
What are the Benefits of Ruby on Rails? After Two Decades of Programming, I Use Rails

Sometimes I hear people complaining about their clients, saying that they insist on using Rails, that they’ve had too much Kool Aid. If they are recruiters, they almost feel sick in the stomach from perspective of having to find yet another ROR primadona. From the programmers point of view it sometimes looks like clients don’t have a clue. However, I believe most clients know their options just fine and they still decide to go with Rails.

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Daniel Lewis
Build Dumb, Refactor Smart: How to Massage Problems Out of Ruby on Rails Code

Sometimes, clients give us feature requests that we really don’t like. It’s not that we don’t like our clients, we love our clients. It’s not that we don’t like the feature, most client-requested features are aligned perfectly with their business goals and income. Sometimes, the reason we don’t like a feature request is that the easiest way to solve it is to write bad code, and we don’t have an Elegant Solution on the top of our heads. This will throw many of us on fruitless searches through RubyToolbox, github, developer blogs, and stackoverflow looking for a gem or plugin or example code that will make us feel better about ourselves.

Well, I’m here to tell you, it’s okay to write bad code. Sometimes, bad code is easier to refactor into beautiful code than a poorly thought out solution implemented under a time-crunch.

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