Senior Backend Developer - C# .NET
Senior Backend Developer - C# .NET
Sofia, Bulgaria
7,000-8,000 BGN (net)/month DOE
Puzzel: The Low-Down 🔍
Puzzel is a leading provider of cloud-based contact center solutions, empowering businesses to deliver exceptional customer service. Our platform combines omnichannel contact center, workforce management, and AI-driven analytics to optimize customer interactions and operational efficiency.
With 25 years’ experience since our foundation in Norway, we’re already #1 in the Nordics, growing rapidly in the UK and expanding into the Netherlands and Finland in 2024, but our ambition is to become the clear European market-leader in the coming years 🚀
Why we’re proud
- 2024 CX Awards Winner, ‘Best Mid-Market Contact Center Platform’
- Puzzel was recognised as the 'most innovative European-founded CCaaS provider' and top 3 globally by Frost & Sullivan in 2023
- Best Practices Company of the Year 2023
- Consistently high Glassdoor rating
- 2023 customer NPS score of 37
- Puzzel places high importance on work-life balance and flexible working hours - as recognised by Flexa, placing 16th overall for work:life balance in 2025!
- We are working with Mercer on salary benchmarking, to ensure pay equality and market competitiveness
Key Data Points
- €57m revenue in FY 2024 (up from €50m in 2023)
- Currently ~300 employees
- Used by more than 1100 businesses across 40 countries
- Servicing ~60,000 customer service agents on a daily basis + 800 million customer interactions yearly
What you'll do 🏡💻
The Senior Backend Developer will be an integral part of our Self-Service Automation development team, split across Malmö, Sweden and Sofia, Bulgaria (which is where the backend team are mostly based).
The Virtual Agent is the start of the majority of customer journeys and with the recent advances in generative AI, is technologically at the forefront of what we do. Meanwhile, Digital Engagement helps to guide prospective customers through their buyer journey on the website, which results in increased conversion of sales – inherently beneficial to any business.
Even if you’ve not worked with a directly comparable product, you should of course have an interest in this field and pushing the envelope!
It’s important to mention that this is an individual contributor role with no direct reports, so we're looking for hands on developers at a senior level.
Key Responsibilities
- Design, develop, test and document software used in our Puzzel Chatbot & Digital Engagement offerings.
- Lead technical development projects, with particular focus on backend.
- Develop, maintain, document and support the software development in C# & T-SQL.
- Write and document cloud agnostic code in a clear structure, that is easy for others to read and understand.
- Collaborate closely with colleagues in Bulgaria & Sweden predominantly (and across other Puzzel locations as required).
- Ensure a very high standard of reliability & stability.
- Help design and fulfil component roadmaps for the designated product team.
- System architecture.
The must haves 💪
- Degree in Engineering, Computer Science or equivalent
- 5 years development experience
- Experience with large scale web applications
- Experience in developing high security web apps
- Experience/proven knowledge in: C#
- Experience in .NET Core
The nice to haves ➕➕➕
- SQL Server or T-SQL
- Docker containers
- Kubernetes
- Microservice architecture
- Azure pipelines
- Experience of complex integrated systems with several different tech stacks
- Agile methodology
- Machine Learning or AI
- Data security
- Continuous delivery
- Git
- Elastic search (or similar)
The location
NV Tower, bulevard „Doctor G. M. Dimitrov“, Sofia, Bulgaria
The team typically go in 2-3 days/week, with the rest working from home; the office is there 5 days/week if so desired!
What’s In it for You? 💰
- Competitive salary. Please don’t expect to automatically come in at the top end of the range – this will be for candidates that tick 95% of the boxes!
- Flexible, hybrid approach to working; split your time between the office and home
- Access to a state-of-the-art office with a partly subsidized sports centre (gym/spa/pool)
- You get to be part of a fun, driven and supportive team
- Gift on your birthday
- Annual Summer and Christmas parties
- Excellent development opportunities and a great company culture
What to expect from the interview process ❔
- Screening call with Talent Acquisition
- 1st interview with the Development Manager + Product Owner
- 2nd interview with a Lead Developer, local HR + Dev Manager
- Final interview with Dev Manager + Director of Development
Puzzel Values 🎯
- Built on Trust – trust is an intrinsic Nordic value, upon which Puzzel has been built. We trust each other and our customers and partners trust us.
- Stronger Together – working together in a genuinely collaborative way, with a shared purpose, we have an empowered organisation that is better equipped to delight customers and partners.
- Stay Hungry – have a continuous hunger to raise our game, innovate and be the best we can be professionally.
Equality and Diversity 🌍
We want everyone at Puzzel to be their true, authentic selves at work irrespective of nationality, race, ethnicity, religion, sexual orientation, gender identity, physical ability, age, or economic background.
Whilst we are proud to already have a diverse workforce from across the globe, we are aware that things could always be improved – for example, we currently have a ratio of female 26:74 male employees, which whilst not uncommon for the tech industry (average in SaaS is 26% female), it’s far from ideal. So, what are we doing to improve this?
- Our Global Leadership Team (C-suite) has shifted from 100% male to 60 male: 40 female in the past 12 months.
- We have increased our % of female hires from 23.6% in 2021 to 38.5% in 2023.
- We are partnering with the likes of Flexa, who have significantly higher-than-average talent pools of candidates from diverse backgrounds.
- We are working with State Employment initiatives in Norway and Sweden to bring candidates through internship/apprenticeship routes and are investigating similar initiatives in the UK and Bulgaria.
- By raising awareness and transparency, we are hoping to further attract a diverse workforce.
We are continuously striving to foster an inclusive and diverse environment, where everyone is celebrated for who they are. If there is anything we can do to support you in the interview process, or beyond, please let us know.
One Last Thing ☝🏻
Even if you feel you are only a 75% match for this role, we still want to hear from you. This list is purely indicative. Skills can always be learnt.
Please note that we are not able to provide sponsorship for this role, so you must have eligibility to work in the country you are applying for.
By applying you accept the terms of our Privacy Notice which can be found on our website. Puzzel are not considering candidates that do not have a work permit in the country we are hiring in.
- Department
- Technology
- Locations
- Sofia, Bulgaria
- Remote status
- Hybrid
- Monthly salary
- BGN7,000 - BGN8,000

Colleagues
Sofia, Bulgaria
Puzzeler perks
-
Great compensation package:
Holiday days • Pension Insurance • Benefits package
-
Work - Life Balance:
Flexi time • Remote working options • Nice city offices
-
Company social activities:
Training and events attendance • Company-wide kick off events • Team meet-ups
Workplace & culture
We are proud with our strong company culture and friendly atmosphere, pleasant working environment and colleagues with extensive experience and technical expertise.
We have an environment that is characterized by freedom and confidence to the individual employee, professional challenges and great professional and personal development opportunity.
Great people, of course! We Puzzelers are a diverse and inspired bunch who work hard and are passionate about what we do.
To work at Puzzel is an opportunity to influence and shape your own position in a company with big plans ahead.
Read what it's like to work at Puzzel
About Puzzel
Puzzel is the leading European Contact Centre as a Service (CCaaS) provider. We are headquartered in Oslo, Norway and have operations across Sweden, Denmark, Finland, United Kingdom, Bulgaria and the Netherlands.
Senior Backend Developer - C# .NET
Loading application form
Already working at Puzzel?
Let’s recruit together and find your next colleague.