Growth: 825 percent
Business: Internet marketing
Traffic Trends specializes in marketing online stores. Services include SEO, adword campaigns, social media, content marketing, and analytics.
Since its founding, the firm has attracted custom from large specialist retailers, ranging from sellers of women's underwear to consumer electronics. The company attributes its success to keeping a tight focus on online, rather than widening its offering to bricks-and-mortar business.
Growth: 843 percent
Business: Software development
Serengeti is an outsourcing/nearshoring software developer working mainly for companies in Western Europe.
The company particularly promotes its so-called 'Extended R&D Workbench'. The customer gets to work with the same team of Serengeti engineers from the start of the project to its completion, starting with a core team embedded in the client's business structure.
Team members are added as needs become more apparent as the project progresses. Serengeti also offers middleware services.
Growth: 933 percent
Business: Software downloading hubs
ITNT offers software download portals mainly aimed at the Romanian market. Its largest online collection is Soft32.com, which features downloads of free tools, trial versions of commercial software, and even service packs for Microsoft products.
Offering downloads for Windows, Mac and Mobile, Soft32 is offered in Romanian, English, German, French, Spanish, Italian, and Portuguese.
Growth: 962 percent
Business: Software development, embedded software
Another software developer, High Tech Engineering Center (HTEC) serves customers in the EU and US.
Based in the Serbian capital Belgrade, HTEC claims a number of high-profile customers, which it attributes to its specialization in embedded systems and custom electronics. According to its website, HTEC serves customers from remote offices in Belgrade as well as through on-premise teams.
Growth: 998 percent
Business: Payment processing
ZebraPay offers online payment services and has a network of over 1,000 payment processing terminals in Romania, mainly in the capital Bucharest.
The terminals allow for payment of bills, the topping-up of credit for mobile phones and Skype, and buying magazine subscriptions, without the need for a credit card. Since last year, ZebraPay also sells Bitcoin, in exchange for four percent on the prices of the coin-trading services.
Growth: 1,004 percent
Business: Mobile and web application development
Netguru is a developer of applications for web and mobile, working from seven locations in Poland.
The firm's portfolio consists of development of cloud-based software, mobile applications, and custom online systems. Much of its attention is focused on growing as a full-stack development house, with its roots in web development.
Growth: 1,004 percent
Business: Application development and deployment
The oldest company on the list is also one of the more traditional ones.
Founded in 1996, BSP is a developer and integrator of business applications and Microsoft's first partner in Slovakia. Besides development, BSP offers integration, document management, security and licensing.
Growth: 1,209 percent
Business: Accommodation-comparison website
Last month, Szallas.hu was acquired by a bank and a venture capitalist, with a view to accelerating its international expansion.
Already, revenue has exceeded €30m, and last summer Szallas.hu opened offices in Poland, Croatia, Romania, and Slovakia. Szallas.hu has profited mostly from the steep rise in the number of reservations conducted online. Szallas.hu was last year's leader in the Deloitte rankings.
Growth: 1,665 percent
Business: Mobile payments
SkyCash has been a permanent fixture in the Polish market for mobile payments since it was founded in 2008. By 2015, it has become the clear market leader in the country when it comes to paying for public transport, parking space, and cinema tickets.
It also claims to have more than two million users who make 500,000 transactions each month. The main revenue maker for the company is paid parking, for which SkyCash can offer over 90 percent coverage in the entire country. Over the years, SkyCash has improved usability and design of its app.
Country: Czech Republic
Growth: 1,971 percent
Business: Data warehousing and business intelligence
The top spot in the region goes to Czech company Simplity, which has developed a software suite for data warehousing and business intelligence.
The company was founded by a former Czech Oracle employee and sells its suite, Accurity, to banks and telecoms companies worldwide.
Besides Accurity, Simplity offers custom solutions based on technologies by Teradata, Oracle, Sybase, and Microsoft SQL, among others. This year, Simplity is earning revenues of CZK 100m (€3.7m), up from CZK 82m (€3.03m). The company currently has premises in Prague and Brno, and next year is planning to open offices in Silicon Valley.