Senior Backend Engineer at hyperexponential at Hyperexponential

Senior Backend Engineer 

(remote until further notice due to COVID19)  


Advanced mathematics 

Satellite launches 


Concert tours 

Smart people 

...Telephone poles

What do these things have in common? hx! The most interesting startup you haven’t heard of yet. We combine advanced mathematics, the latest technology and the smartest people to help our clients solve truly hard problems with weird and wonderful datasets.

Our mission

To reimagine technology to transform analytical decision-making, helping our customers make smarter decisions faster.

Who are we (and what do we do?)

We are a successful three-year-old startup disrupting the speciality insurance sector with our SaaS platform, Renew. Renew lets actuaries rapidly build and iterate complex mathematical models in an advanced web-based development environment which are then used by underwriters to price insurance for special cases like hurricanes, satellite launches, concert tours and telephone poles (seriously!)

The nature of our problem space means we work on truly hard, interesting, varied problems that you’re unlikely to find at most other companies. If that sounds interesting – read on!

 How do we do it?

We’re a small but growing team of smart and kind people who are deeply passionate about what we do. Here’s how we work:

Team + People


  • Live our values of excellence, initiative, passion, kindness and thoughtfulness
  • Are excellent to one another, putting our colleagues and the team ahead of ourselves
  • Work collaboratively when needed and with trust and aligned autonomy when not
  • Take pride in our work by building quality in and caring about how it works in production
  • Are always learning, sharing knowledge and pushing ourselves to be better every day
  • Can say “I don’t know” or ask for help safely without fear of judgement


  • Frontend: React (w/Redux, Sagas, styled-components), TypeScript
  • Backend: Kotlin (w/Spring Boot), plus some Java, Go and Python 
  • Platform & Infra: AWS (w/Lambda, DynamoDB, PostgreSQL RDS, ECS), Terraform, Docker
  • General: Gitlab, Miro, Notion

Ways of working


  • Deliver small increments of work through an agile/kanban/lean process
  • Think first, act fast - then iterate 
  • Continually improve our ways of working with tight feedback loops 
  • Believe failure is part of success 
  • Understand the need to balance technical purity against the need to deliver 
  • Appreciate the value of simplicity and the power of ‘boring’ 

What will you do?

2021 is going to be a big year for hx. Our profile is growing rapidly, and our customer base with it. We have tonnes of exciting features to develop, and we want to deliver more of them in parallel, sooner, safer, than we’ve ever done before. To make sure we’re set for the future we’re going to be looking at all our systems, refreshing most of them and reworking the rest to get us ready for anything.

It’s a deeply exciting prospect for us, and the Senior Engineers are critical to its success.

As a Senior Engineer you’ll:

  • Help us build the right thing by working with product managers, designers, fellow engineers and customers to understand problems and develop solutions 
  • Help us build the thing right by writing high quality, thoughtful, simple, commented, documented, tested, well-structured code aligned to our constants, principles and standards
  • Drive our technical standards, decisions, and strategy
  • Guide, mentor and advise other members of the team
  • Continually learn and improve yourself. Experiment and play with new technologies through your work, extracurriculars and hackathons
  • Help reduce friction and eliminate impediments that slow us down
  • Promote hx in the community by contributing to open source projects, writing on our blog and/or presenting at virtual meetups/conferences 

In your first week you’ll:

  • Meet everyone at our weekly company breakfast
  • Get set up, get to know hx and your team
  • Start learning our ways of working
  • Attend your first hx Engineering Forum, where we discuss and debate all things tech
  • Wrap the week at our all hands Show + Tell

Within your first month you’ll:

  • Know our ways of working inside-out
  • Be adding value by developing features and fixing bugs
  • Be reviewing code against our constants, principles and standards
  • Add your voice to our design/ideation sessions 

Within three months you’ll be:

  • Delivering major features from ideation through development to production
  • Helping us make hard decisions, and improving our standards and ways of working
  • Guiding, mentoring and advising other members of the team

Who are we looking for?

You should apply if you:

  • Love everything you’ve read so far
  • Have significant experience using Kotlin (or Java) to build and operate cloud-native applications at scale from design to production
  • Have a good working knowledge of fundamental computer science and software engineering principles (algorithms, data structures, complexity, design patterns, architecture)
  • Value our values (excellence, initiative, passion, kindness, thoughtfulness) as much as we do

You should definitely apply if you:

  • Have experience with any of our other technologies (i.e you’re T-shaped or ’full stack’) and/or technologies equivalent, adjacent or complimentary to ours
  • Love science, technology, engineering and/or mathematics
  • You have experience with insurance or insurtech
  • You like any, many, or all of the following: stroopwafels, meditation, yoga, weightlifting, competition shooting, Japanese music, motorcycles, classic flash games, surfing, curry, golf, CTFs, dogs or running

What do we offer?

  • Salary up to £80,000
  • Very team-friendly EMI share options
  • £5,000 annual learning & development allowance
  • 33 days annual leave (inc. public holidays)
  • £250 gadget budget
  • Choice of equipment (top-spec Apple or Dell laptop, screens, mechanical keyboard, etc)
  • Huge opportunity for personal development and mastery as we grow together 
  • Regular remote hackathons, lunch & learns, snacks, socials and games nights
  • Team breakfasts and lunches, snacks, drinks fridge, socials, fun office @ the Peckham Levels, annual team trip somewhere warm (sadly on hold due to COVID19)

What’s next?

hx is different and so is our hiring process. We want to see you at your best, so we let you customise the major stages – essentially a “choose your own adventure” hiring process that adapts to your individuality.

  1. Initial call with our Talent team to kick things off 
  2. Introductory call with your future manager (with your choice of questions)  
  3. Technical assessment with your future colleagues (with your choice of format) 
  4. Meet the team (with your choice of who) + Meet the CTO + Meet the CEO 
  5. We offer! 

Diversity @ hx

We are committed to diversity and equal opportunity. We’re a smart and kind team who believes that the more inclusive we are, the better our work and culture is. We are not yet where we want to be in terms of balance, but it is our mission to build a team that represents a variety of backgrounds and perspectives and we are working hard towards that goal.

If you like the sound of this role but you’re not totally sure whether you’re the right fit – please apply anyway and we’ll let you know either way. Remember: you miss every shot you don’t take!

PS Our new blog is now live! 

Check it out at 

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