Senior Backend Developer

We’re looking for a developer who take pride in crafting solutions that help enterprises to growth. We are B2B Fintech in Payments, helping enterprises to improve financial operations:

Do you…

– enjoy deeply understanding business problems before crafting solutions?

– find satisfaction in designing systems that bring order to complex business operations?

– take pride in building robust architectures that scale reliably?

– excel at modeling complex business processes into elegant data structures?

Are you…

– someone who enjoys mastering your tools and continuously improving?

– detail-oriented with an eye for systematic approaches?

– comfortable owning projects from start to finish?

– drawn to building solutions that create order from complexity?

Here’s what makes our work different

We’re not just building a B2B software – we’re creating payment systems that transform how businesses operate. Our enterprise clients trust us to understand their complex processes and turn them into efficient solutions.

Join a team of other self-motivated individuals who excel at their craft. We take pride in the work we do and get excited about solving problems. We only hire self-motivated “drivers” and developers with lots of experience.

You’ll join a team that values…

– Deep understanding of business processes

– Time to think through solutions properly

– Consistent, high-quality execution

– Protected focus time for complex challenges

– Long-term reliability over quick fixes

Your Day-to-Day

– Design and build robust backends that power business transformation

– Create sophisticated data models that reflect complex business rules

– Develop reliable integrations between modern and legacy systems

– Build powerful APIs that connect disparate business systems

– Implement secure, scalable solutions for business-critical operations

Experience Required

– 5+ years programming experience with Python

– Understanding of APIs (web services)

– Willingness to step forward and suggest ideas, comments, remarks

– Ability to communicate with clients and potential clients.

– Django framework expert

– Django REST Framework and AWS experience are nice to have, but we’re happy to help you with learning them on the job

– Experience building and maintaining large-scale applications

– Excellence in database design and optimization

– Understanding of complex data modeling and migrations

– Clear written communicator that prefers emails to meetings

– Portfolio showing systematic, well-structured work

Technologies We Use

– Core Technologies: Django Rest Framework, PostgreSQL, AWS Lambda

– Supporting Libraries: Pandas, OAuthlib (among many others!)

– Testing: strong testing culture with pytest

The Environment

– Stable, focused work environment

– Protected development time

– Regular, predictable schedule

– Email > meetings

FAQ

Is this a full-time role?

Yes. Ideally this person would join us full time asap.

Can I work remotely full-time?

Yes. We also have an office in central London.

What’s the hiring process?

Very simple:

STAGE 1:

Short intro call to review the main points of the process and explain the technical exercise.

– You will need to either: (a) do a small project at home, or (b) you will share with us an interesting repo you have on GitHub (or another version control platform).

– Duration: [10-15 mins]

STAGE 2:

Your phone call will be with Ron Danenberg (Founder & CTO).

– This will be to find out more about your background and introduce you to Kolleno.

– We’ll want to hear about your greatest hits and why you’re proud of them.

– We’ll discuss your experience in depth and explain how growth and technology will work together at Kolleno.

– We will have a discussion about the code you wrote (exercise from step 1), and the technical challenges at Kolleno.

– Duration: [60 mins]

STAGE 3:

If you progress to the next stage, we will introduce you to key team members (lead frontend developer and CEO).