C# Developer at Tessian
United Kingdom

At Tessian (formerly CheckRecipient), we have the ambitious goal of protecting enterprise networks against new and intelligent cyber threats, making it impossible for sensitive information to end up in the wrong hands.

Through advanced machine learning and natural language processing (NLP), Tessian prevents breaches in real-time, outsmarting traditional rule-based, admin-intensive approaches which can only report a breach after it has occurred.

Founded by a team of Imperial College engineers, we’re backed by some of the world’s leading technology investors. We work with international clients in the financial, legal and professional services sectors who trust us to find the most intelligent ways to keep their data secure.

We’ve recently closed a fundraising round of $2.7m led by Accel and LocalGlobe and we are looking to work with the brightest minds to help us accomplish our goal and help us defend our clients against the biggest cybersecurity problems.

Tessian joins Microsoft Accelerator

We're delighted to announce that Tessian has been selected to join the Microsoft Accelerator. The programme, which will begin in October, will provide us with unprecedented access to top Microsoft partners and customers, powerful business connections, and world-leading technical knowledge.

Developing at Tessian

We hope to demonstrate to our clients that enterprise software can be done differently. We aim for a minimal-disruption approach to tackling email-based threats and we need our software - and our developers working on our client-side integrations - to enable this.

Most enterprise clients access their emails via Microsoft Outlook, so our Outlook add-in is a key integration, and the developer in this role will be working on the product at the very heart of our Company.


This role is very varied and will offer opportunities to work across some of the following areas:

Undertaking programming in .Net (C# or VB.net), and working on our add-ins with a view to scalability and resilience

Investigating and working with both testing and deployment

There is also an opportunity to work on mobile development for the app-versions of our products.


Technical Requirements

Does this sound like you? Then please apply!

Experience with:

Programming: .Net (C# or VB.net)


Microsoft office integrations / add-ins, Outlook, and Outlook add-ins

Tessian's Awards

Winner - Cyber Security Breakthrough Overall Enterprise Email Security Solution Provider of the Year 2017

Winner - CogX 2017 Best Innovation in Data Protection and Privacy

Winner - INFOSEC 2017 Most Innovative Cyber Security Company

Winner - Info Security Product Guide’s Global Excellence Awards 2017 for the Best Security Startup

Winner - WIRED Security 2016 Best Startup Award

Winner - LegalGeek Best Machine Intelligence Start Up 2016

Our Team

You can check out some photos of our team on our Instagram, or check out our team page.

Other Requirements

Must be eligible to work in the UK


Competitive salary (from £35,000-75,000 p.a. - amount is negotiable dependent on experience and fit) and meaningful equity options

25 days of holiday leave as well as 8 days off for UK public holidays

Choose your own tech kit - laptop & OS

Regular team socials and activities

Flexible work start-times for the Tech team

Ad-hoc work from home

Personal Development; we are always keen to encourage personal development, so:

Tessian Library: if you have a work-relevant book you want to read, we'll buy it for you to read then add it to the library!

We are always willing to consider requests for personal development training and courses.

Annual personal development fund

Central London office location (EC1Y 8SL) with shared roof terrace and community events (including a monthly feast and 'cake Wednesdays'!) and:

Weekly Ocado office-food deliveries of fruit, nuts, bread, cereal and snacks

Amazing Pact coffee and a huge selection of Twinings Teas in the Office

Annual benefit and Salary Reviews

Cycle to work scheme, eyecare vouchers and childcare vouchers

Subscription to the Headspace Meditation app

Yoga in the office at lunchtime once a week

Pension plan contributions

Relocation: if you are coming from abroad, we will provide accommodation in an AirBnB for a week to help you make the move, and can make salary payments to an international bank for the first three months. We also have some handy tips and checklists to help with your relocation.

Equality and Diversity

Tessian is an equal opportunity employer, committed to equality and diversity amongst both our employees and prospective applicants. You can read our equality and diversity statement here. We're also a corporate member of WISE.

How to apply

Please attach your résumé and take the time to write a quick cover letter about why you’d like to work at Tessian and specifically what attracts you to this role.

We look forward to hearing from you!

Important Notices:

Please note that we do not accept applications or résumés from recruiters unless we have specifically asked a given recruiter to submit candidates for this role