Software Engineer 2 (.NET/C#) - OneBox Backservices

Allegro; Warszawa; Hybrid; PLN 163,000 - 232,000; Full time

Benefits offered by this job

Well-located offices

Laptop provided

Cafeteria plan benefits

English classes

Training budget

Volunteer day

Social events

Job summary

Allegro Tech is seeking a backend engineer to design and scale high‑performance services powering the OneBox network from Warsaw. You’ll own components from architecture to deployment, building reliable systems used by millions of parcels daily.

Join a hybrid work environment with modern tech like C#, .NET Core, ASP.NET, REST, PostgreSQL, Redis, Docker and Kubernetes. Enjoy generous benefits and opportunities to grow within Allegro Tech.

Qualifications

• Solid proficiency in C# and .NET Core / ASP.NET for building reliable backend systems and REST APIs.
• Relational database experience with PostgreSQL; caching with Redis and basic performance tuning.
• Cloud-native tooling with Docker and Kubernetes; familiarity with large IoT device networks is a plus.
• Fluent Polish and English (at least B2); willingness to take end-to-end ownership and mentor peers.

Skills

C#

.NET Core

ASP.NET

REST APIs

Polish (B2)

English (B2)

Tools

PostgreSQL

Redis

Docker

Kubernetes

Azure Service Bus

Consul

GitHub Actions

Job description

• Impact at Scale: We are part of Allegro, developing high-performance IT systems for OneBox backend.
• Massive Scale: Design and build high-availability systems used by tens of thousands of users. This is high-performance engineering in practice.
• Modern Tech Stack: Work with a world-class environment using C#, .NET Core, ASP.NET, REST, PostgreSQL, Azure, Docker, Kubernetes, EntityFramework, and Redis.
• True Ownership & Autonomy: We live by a \"you build it, you run it\" philosophy. You'll join an autonomous team with full ownership of the services you create, from design to deployment.
• Complex Challenges: You will tackle complex backend problems, using technology to solve real-world business challenges.

Join the team building the backend powering our OneBox network! Imagine walking down the street, spotting a OneBox parcel locker, and knowing that your code helps drive it – that's the kind of impactful project you'll be working on. Our systems process millions of parcels, operating at high scale, high complexity, and deep integration close to the hardware.

In this role, you will work with physical machines, shape our backend architecture, and scale our infrastructure to support a continuously growing fleet of OneBoxes. We prioritize high reliability, modern engineering practices, and a supportive team culture, offering you a unique opportunity to solve complex real-world challenges at scale.

Important things for you

• Flexible working hours in the hybrid model (4/1) - working hours start between 7:00 a.m. and 10:00 a.m. We also have 30 days of occasional remote work.
• The salary range for this position depending on the skill set is as follows (contract of employment, tax-deductible cost):
• PLN 14 600 - 20 825
• Annual bonus based on your annual performance and company results.
• Our team is based in Warsaw.

We are looking for people who have:

• Core Backend & Architecture: Solid proficiency in C# and .NET Core / ASP.NET for building reliable, maintainable backend systems; practical experience in building and consuming REST APIs according to industry standards; comfortable participating in architectural discussions and contributing to overall system design.
• Data & Distributed Systems: Practical experience with relational databases like PostgreSQL, including data modeling and basic performance tuning; hands‑on work with asynchronous messaging systems (Azure Service Bus or similar message brokers); understanding of caching concepts and tools like Redis to support system performance.
• Cloud & IoT Infrastructure: Hands‑on experience with cloud‑native tooling such as Docker and Kubernetes; experience with - or open, excited, and aware of working with - large IoT device networks and ecosystems (a plus).
• Delivery, Culture & Languages: Enjoy sharing knowledge and encouraging good engineering practices; eager to grow toward end‑to‑end task ownership across the software development lifecycle with mentorship from senior engineers; proficient in Polish and English (at least B2 level).

What's in it for you:

• Well‑located offices (with e.g. fully equipped kitchens, bicycle parking, terraces full of greenery) and excellent work tools (e.g., raised desks, ergonomic chairs, interactive conference rooms).
• A 16\" or 14\" Dell with Windows and all the necessary accessories.
• A wide selection of fringe benefits in a cafeteria plan - you choose what you like (e.g., medical, sports or lunch packages, insurance, purchase vouchers).
• English classes that we pay for related to the specific nature of your job.
• A training budget, inter-team tourism (see more here), hackathons, and an internal learning platform where you will find multiple trainings.
• An additional day off for volunteering, which you can use alone, with a team, or with a larger group of people connected by a common goal.
• Social events for Allegro people - Spin Kilometers, Family Day, Fat Thursday, Advent of Code, and many other occasions we enjoy.

And that's just the beginning! You can read more about the benefits here.

#goodtobehere means that:

• You will join a team you can count on - we work with top‑class specialists who have knowledge- and experience‑sharing in their DNA.
• You will love our level of autonomy in team organization, the space for continuous development, and the opportunity to try new things. You get to choose which technology solves the problem and you are responsible for what you create.
• You will value our Developer Experience and the full platform of tools and technologies that make creating software easier. We rely on an internal ecosystem based on self‑service and widely used tools such as Kubernetes, Docker, Consul, GitHub, and GitHub Actions. Thanks to this, you can contribute to Allegro from your very first days on the job.
• You will be equipped with modern AI tools to automate repetitive tasks, allowing you to focus on developing new services and refining existing ones (also leveraging AI support).
• You will create solutions that will be used (and loved!) by your friends, family and millions of our customers.
• You will meet the Allegro Scale, which starts with over 1000 microservices, an open‑source data bus (Hermes) with 300K+ rps, a Service Mesh with 1M+ rps, tens of petabytes of data, and production‑used machine learning.
• You will become part of Allegro Tech - We speak at industry conferences, cooperate with tech communities, run our own blog (it's been over 10 years!), record podcasts, lead guilds, and we organize our own internal conference - the Allegro Tech Meeting. We create solutions we love (and can) to talk about!