Top 10 Custom Software Development Companies in London

Yuri Filatov
10 min readJun 28, 2022

As a global city, London is home to numerous businesses from various sectors of the economy. Information technology is also flourishing here attracting leading IT professionals who develop state-of-the-art software. In this piece, we’ll review 10 custom software development companies in London that the Clutch service rates as the best.

Searching for the right developer

When thinking about enhancing its capacities using information technology, a business must choose either off-the-shelf or custom software. Each type has its benefits and drawbacks. For an enterprise willing to evolve, a custom platform or app is more efficient because it provides better customization, enhanced security, and adaptability. Tailor-made apps meet the requirements of a particular company, in this way they are much more relevant than ready-made ones. Even though initial investments in the development of such software are considerable, its uniqueness will help you stay competitive in the market and make more profit.

An experienced IT company will create a web or mobile platform of any complexity. But how do you know that this or that software provider is reliable and will offer the most efficient solution? It should be a reputable company with a team of IT professionals and a portfolio of efficient software products. You can find such a partner if you thoroughly examine various rankings and customer reviews on such platforms as Clutch.

This renowned service offers its users rankings of B2B companies from 500+ industries. They are classified by type of services, size, location, and other important criteria. We have already found 10 software providers in London and offer you to have a look at the results of this search.


Since 2007, Andersen has carried out more than a thousand projects. 3100+ IT specialists work here building state-of-the-art custom software solutions and updating and scaling existing ones. Andersen cooperates with leading businesses in healthcare, fintech, automotive, retail, and other industries. Such globally known brands as Johnson & Johnson, Ryanair, Samsung, Siemens, etc. have opted for a partnership with this reliable IT developer. SMEs also profit from the software products created by this European company. The customer loyalty rate is an impressive 90%. Recurring clients are willing to recommend the company to their partners.

Currently, Andersen has 4.9 out of 5 stars on Clutch which proves the impeccable quality of its services and expertise. In 93 customer reviews, clients share their positive feedback mentioning the professionalism, deep knowledge, and enthusiasm of Andersen’s employees ready to accept any challenge and build cutting-edge software. Guido Maria Magliano, Director of operations at VERSES, says that the quality of the team’s services is outstanding. Andersen’s developers, BAs, UX/UI designers, and other experts are amicable, motivated, and nice to work with.


DCSL GuideSmiths

Founded in 1994, DCSL GuideSmiths has won numerous awards for its excellent and cost-effective software solutions. The company’s staff members are currently working in the UK, Spain, Hungary, and Romania. Mainly, they cooperate with midmarket businesses (60%) from the following industries: automotive, government, education, fintech, hospitality & leisure, healthcare, etc. A team of 300+ IT experts is ready to offer onshore and nearshore delivery services.

The company’s core capabilities are web and mobile app development, IoT solutions, custom CRM & ERP systems, custom databases, software and hardware integration, and others. It is a Microsoft Gold Partner and is ISO 9001 & ISO 27001 certified.

Among the key clients of the company are Mitsubishi, Skanska, and Water Aid. Clutch users rate DCSL GuideSmiths at 4.8 out of 5 stars mentioning the team’s flexibility, the ability to handle complex problems, and the level of involvement. In his customer review, James Jackson-Nichols of Fine+Rare assures Clutch users that the professionalism of the company’s staff is a good reason to entrust them with a software project.


GoodCore Software

Since 2005, GoodCore Software has been cooperating with businesses in the UK and abroad. The developer has already taken part in more than 110 projects for such industries as fintech, healthcare, education, real estate, and others. It has partnered with private companies (with the main client focus on small businesses) and governmental organizations. In an agile manner, IT specialists create feature-rich apps that can meet the requirements of any customer.

This software provider is open to cooperation on various engagement models, depending on the need of a client. MVP development, web, and mobile app development, UX/UI design, fixed-price projects, dedicated teams, etc. — you can choose anything you need and be sure that the company’s employees will help your business grow with efficient value-for-money solutions.

Reviewers mention the employees’ methodology, commitment to work, and friendliness. David Walford of EchoVision, LLC is truly impressed with their development skills. Currently, GoodCore Software has 5 out of 5 stars on Clutch, which is an awesome result. Definitely, this company will help you turn any challenging idea into reality.


Imaginary Cloud

This IT service provider specializes in UX/UI design and web, mobile, and AI development. Since 2010, it has already created more than three hundred apps for various industries. Its key customers include the renowned BNP Paribas and Nokia. Recently, Imaginary Cloud was listed among the top 100 UK Design Firms. It’s not the first time this software provider appears in a Clutch rating. It has already been listed as one of the fastest-growing companies and has won other meaningful awards.

The company offers various IT services, from product ideation to its improvement. It is distinguished by a user-oriented approach: the main goal is to design software that will simplify people’s lives. The tech stack is wide: Imaginary Cloud’s designers work with such tools as Figma and Adobe Creative Suite and its developers have mastered React, Angular, Node.js, Ruby on Rails, Python, and others.

5 out of 5 stars and 16 positive reviews are evidence that Imaginary Cloud can cope with any project. João Santos of Learninghubz confesses that it is the best software development company his business has ever partnered with.



Infinum has been developing software since 2005 and has already transformed numerous businesses that value technology. Such world-famous brands as Porsche, T-Mobile, Coca-Cola, Nike, and others have ordered digital products from this software development company. Recently, Infinum has won the iF Design Award in collaboration with the world-famous Philips.

The scope of Infinum’s software solutions is vast: landing pages, web, and mobile apps, back-office systems, etc. Millions of users across the globe enjoy them and gladly recommend them to others. The key industries the company covers are fintech, healthcare, telecommunications, utilities, and others.

Clutch users rate this software provider with 4.8 stars out of 5. Judging by their reviews, a client will profit from the collaboration with this young yet experienced team. Developers are great not only at certain technologies but at communication as well. They will pinpoint what a business needs exactly and deliver up-to-date efficient solutions.


Bit Zesty

This London-based software company mainly partners with SMEs, nonprofits, charities, and startup organizations from such sectors as healthcare, consumer products & services, eCommerce, etc. It aims to deliver innovative solutions and provide support and maintenance whenever a client asks for them. Should you need to add new features to an existing app, this company is open to carrying out your idea. It offers team augmentation services, and its professionals support such technologies as Ruby on Rails, JavaScript, React +Vue.js, Python, Elixir, and React Native.

Bit Zesty is involved in mobile and web development. When working on projects, the team performs user research, offers efficient UX design, and opts for agile management.

Bit Zesty managed to deal with the challenges of the COVID-19 pandemic and was rated as one of the best remote working companies in the UK. Thus, the company can offer you the best developers from any part of the world. It also means that the software provider can face any challenges that may occur in our turbulent times and won’t let its customers down.



Theodo is based in London but has development offices in Paris and New York as well. Since 2009, it has worked on more than 500 projects for healthcare, advertising & marketing, fintech, real estate, and other industries. It cooperates with large enterprises and SMEs, and customers value its expertise and the quality of services. One impressive fact proves this: in 2018 and 2019, 100% of Theodo’s clients would eagerly recommend the company to others.

Theodo’s digital experts can seamlessly join a business and help it build effective software. The company strives to maintain transparency and visibility in all stages of development. The team’s goal is to remain flexible and consider all the needs of customers.

In his Clutch review, Henry Leitzinger, Homebrella CEO, says that Theodo’s developers exceeded all expectations while delivering an MVP. In total, Clutch users rate Theodo at 4.7 stars and mention the company’s energetic approach, close attention to detail, and great communication skills of the employees.



TH-EY’s client focus is startups that need custom software solutions, including browser-based apps and websites, and mobile apps. The software company also provides support for legacy apps. Thus, young businesses will find a reliable technology partner ready to build a long-term fruitful relationship. The products developed by TH-EY are modern, scalable, and responsive.

The core of the company is web development. TH-EY’s specialists have accumulated immense experience working with SMEs and large enterprises. They also offer cloud services, UX/UI design, and develop hybrid mobile apps. Some of the products have been integrated with social networks and marketplaces at the request of customers.

TH-EY’s current Clutch rating is 5 out of 5 stars. Clients note the team’s responsiveness, professionalism, and commitment. To put it simply, “Everything was grand”. This remark by James Dent of Susterra Ltd is really helpful for new clients willing to choose a reliable software provider.


Ester Digital

Found in 2015, Ester Digital is delivering software solutions for such industries as healthcare, high tech, eLearning, real estate, and tourism. It mainly cooperates with midmarket companies and helps startups ideate products and develop MVPs. It has also worked with such Fortune 500 companies as Bridgestone, McDonald’s, T-Mobile, etc.

Ester Digital’s team includes experienced UX/UI designers and front-end and back-end developers who work using Agile methodologies and DevOps practices.

Clients rate Ester Digital at 4.9 stars and mention the employees’ profound knowledge, the incredible pace of work, and friendliness. Several reviewers stress that the team members have impressive graphic design skills. No wonder as the company states that design has been its primary focus since the very beginning. So, if your business needs to create a modern appealing website or update an existing one, Ester Digital’s specialists will help you carry out such a task rapidly and most efficiently.



Since 2009, Apadmi has been helping leading businesses create digital products and move forward. The company delivers mobile and web platforms and apps for such giants as BBC, Chelsea Football Club, NHS, Lexus, and others. It also successfully cooperates with SMEs from fintech, retail, healthcare, sports, utilities, and other industries.

More than 200 in-house specialists strive to remain at the cutting edge of information technology. They develop truly unique custom solutions that have received numerous awards.

Judging by the Clutch reviews, customers are happy with Apadmi’s services and gladly recommend them to their partners. Shahzad Mughal mentions the creative approach of the team members who share new concepts with their clients and offer ideas that will help businesses grow and evolve.



With the ever-growing rapid digitalization, any business willing to expand needs efficient software. Tailor-made solutions give companies many benefits and help them keep up with the rapid technological progress. They are scalable and meet all the requirements of both the owner and the target audience.

Finding a reliable IT partner is not an easy task. Rankings and verified customer reviews help business owners hire software developers able to implement the best possible applications and platforms, integrate them with a company’s existing software, and provide support. The top 10 companies on our list are trustworthy. If you wish to learn more, visit their websites for more details and updates.