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Diffblue secures £6.7m funding to scale its automated software writing platform

The funding round, led by Albion Capital, will be used to develop its revolutionary automated software writing platform to add unique new code writing capabilities.


Why We Invested in Diffblue

By Kibrya Rahman

Investment Associate






The Problem: Code Testing and Code Health

Software was predicted to eat the world, and suffice to say, it has. We’ve seen software become critical to company operations, products and services in every industry; and we are still seeing new developments and further complexity. This has led to huge volumes of code being written and it will only continue to grow.

All this code needs regular testing for reasons of efficiency, agility, and quality control. It helps to find and fix problems in the code early, resulting in the delivery of better-quality software more quickly. Testing is required for code maintenance, and it is also important with the increasing shift to agile development where development and testing happen concurrently.

However, there are already not enough software developers available to write all of the necessary code (the global shortage will reach 4m by 2025), and testing code is time-consuming and manual. Currently, businesses are forced to trade off the amount of code they build with the amount of testing they do. And where code quality is prioritised, this can mean that developers can spend up to half their time on testing. Not the best use of this scarce, highly valuable resource – but necessary where code is safety or business-critical.


The Solution: Diffblue – Autonomous AI-for-Code Software

Diffblue is the leading pioneer of software creation through the power of AI. Founded by researchers from the University of Oxford, its flagship product ‘Diffblue Cover’ uses AI for code to solve the problem of effective unit testing, which is one of the fastest ways to detect code errors early on. Capable of writing unit tests 250x faster than a human developer, it helps software teams improve code quality, expand test coverage and increase productivity. Therefore, they can ship software faster, more frequently and with fewer defects.

Diffblue Cover analyses Java, one of the most popular languages for writing code, and can write a unit test in about 2.5 seconds, making it an ideal partner for developers looking to get meaningful unit test coverage quickly. They can focus on writing the key unit tests that verify the intent of their code, while leadership can see the overall picture and address risks and gaps in coverage.

Their customer base already includes leading names across Financial Services, Telecommunications and the Information Services who have seen their testing processes fully automated and reduced from months to hours, with accuracy rates of up to 100%.  


Why Diffblue: What We Are Excited About

The market is large and growing. The software testing market is currently worth $40bn and is forecasted to reach $60bn by 2027. Growth is being driven by underlying secular trends in software development, such as digital transformation, cloud computing, cybersecurity, automation and artificial intelligence/machine learning. 


The technology is unique and differentiated. The underlying AI approach behind Diffblue Cover is called reinforcement learning. Its unsupervised learning model requires no pre-training; it has accuracy rates of up to 100%; it requires low CPU and memory requirements; and it is fully automated and autonomous.


Customers love the product. Diffblue is able to automate some of the most manual work for developers: Diffblue Cover can write a year’s worth of unit tests in 8 hours, at the click of a button. Development teams find it improves the velocity and quality of the software delivered, while DevOps teams find it helps catch errors earlier, and improves deployment frequency, lead time, and mean time to repair. 


A fantastic team and company culture. Diffblue is led by CEO Mathew Lodge, who has over 25 years of cross-functional experience building and growing software companies across the U.S. and European markets. The rest of the team have unrivalled domain expertise, product knowledge and customer centricity.


Our investment in Diffblue reflects Albion’s focus on building category-leading software companies that are leveraging new technologies and machine learning to disrupt sectors crying out for change. It follows our other investments into AI/ML companies such as Black Swan Data, Elliptic, Seldon and Speechmatics.

We are very happy that Diffblue chose us to lead their Series A extension and are excited to join them on their journey.