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Photo by Alex McIl

At some point in the last 30 years, software transitioned from being a powerful productivity boost for individuals to an indispensable tool for teams working together. I’ll bet that having Windows 3.1 and Microsoft Office on your desktop computer in the early 90s helped you get your job done, but you could probably still (just about) have done your job without it if required.

Those days are gone now. It took a while for the organization you worked for to restructure itself around having always-on, networked systems for collaboration and data storage. …


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From Cloudbleed to the WikiLeaks dump of the CIA’s cyber attack arsenal to WannaCry — 2017’s been a busy year for cyber security. Thanks to a slew of high profile political and news events (you know, elections and emails and hacking and stuff) and ongoing privacy concerns, cyber security is something even ‘normal’ people (read: people who don’t work in or know much about tech) are thinking about.

As a tech company creating software that people around the world use, security is naturally something we’re concerned about. But we’re growing increasingly worried so we’re tightening our security.​

What we’re doing

We do a…


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JavaScript (JS), along with HTML and CSS, is one of the core technologies of the World Wide Web (WWW). Every browser natively supports the three. For many, techies and non techies alike, JS has long been associated with front-end development; that ‘thing’ you needed to add a bit of extra stuff on a webpage. In the last decade JS has gained pace as an ‘everything’ language.​


Throughout human history we’ve found ways to increase our individual and collective data storage. It began with our own memories and moved on to cave paintings. Then spoken language, the written word, and numbers: all massively increased our collective storage of knowledge, of data. The printing press and libraries were the next big thing, enabling books to be mass produced and stored, creating vast libraries.

Around 500 years later, just over 60 years ago, the next big leap came: the hard disk drive (HDD)

Here’s how a HDD works:

  • It uses magnetic storage to store and retrieve digital information using…


Ahh… the trusty CSV (comma separated values) file! Knocking around ten years before the first personal computer (that’s since 1972), the CSV file is one of the most ubiquitous and useful file types there is. One of the most common uses: transferring data between databases, often CSV to SQL.

Just what is a CSV file?

A CSV file stores tabular data in plain text format. Each line is a data record and each record has one or more fields, separated by commas.

However, CSV files aren’t standardized (although there are some basic rules). The use of ‘comma’ is misleading because you’ll often find colons, spaces, or…


Programming recently celebrated its 70th birthday, making it older than most active developers today. Many people are unaware that the first coders were women who programmed the first all-electronic, programmable computer in 1947.

It’s apt to celebrate or at least think about the last seven decades of programming because of the huge impact it’s had on human society and will continue to have in decades to come. In fact, the impact is a culmination of and easily comparable to the impact of those of spoken and written language, mathematics, economics, and science.

Almost everything now relies on software. Most companies…


The great NoSQL vs SQL flamewars of a few years ago may have calmed down, but what did we learn?

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​Aside from the fact that arguing on the internet doesn’t get anyone anywhere, maybe not much at all. If anything, the market is even more confusing now than ever — just take a look at the 225+ entries on nosql-database.org.

And with new entrants like CockroachDB and Google Spanner coming onto the market, and traditional database vendors such as Microsoft and Oracle offering more and more NoSQL features, in 2017, are we any closer to knowing what’s the best way…


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At first glance, SQLizer.io is a very simple web application. It has a single form. You upload a file, we read the file, and we turn the data in your file into a SQL script. How hard can it be?

As is often the case, getting something that works 75% of the time isn’t too hard. But getting to 90% takes a lot of effort. And making it to 98% is a real nightmare.

This blog post is about one area of SQLizer where edge cases forced us to put a lot of work into getting something that works almost…


In this year’s Stack Overflow Developer’s Survey 64,000 developers laid bare their innermost developer secrets. How they learn, the tools they use, what they want — it’s all there. The whole survey is a fascinating foray into the brains of developers and the global software industry.

But one thing struck us: SQL is the second-most common programming language, used by 50% of all developers (Web, Desktop, Sysadmin/DevOps, Data Scientist/Engineer) and beaten only by JavaScript — a language half the age of SQL.

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Some of the most common programming languages, Stack Overflow 2017

That’s quite an achievement for a 43-year old…


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D4 is a software studio in Birmingham, with customers all over the UK and further afield.

We currently deliver software projects and offer consultancy in product design, UX and performance optimisation.

We’re now searching for a full-time Mid-level Software Engineer to join our growing team.

You might be just starting out or looking for your second job — either way you’ll have built or contributed to a few different projects and can demonstrate that.

D4 now and in the future

Over the next few years we’ll be moving from a client/agency model into being a multiple SaaS product provider, where products we’ve built will account for a majority of our revenue. We recently hired a marketer as we position ourselves…

D4 Software

We design and build software products. Creators of SQLizer.io, QueryTreeApp.com, and Prodlytic.com.

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