Senior Software Engineer with Python

Codilime; Warszawa; Remote; PLN 180,000 - 280,000; Full time

Job summary

Codilime is seeking a Senior Software Engineer to join a backend-focused team working on a unified network security management platform for a leading cybersecurity vendor. You will design, build, and maintain software, drive architectural decisions end-to-end, and apply AI-assisted engineering practices across the SDLC to land high-quality outcomes.

We value 7+ years of Python experience, strong customer-focused delivery, and fluent English.

Qualifications

• 7+ years of professional Python experience.
• Experience building software products for external customers.
• End-to-end architecture ownership including coordinating without direct authority.
• Hands-on use of AI coding tools in engineering workflows.
• Solid testing strategy and experience.
• Experience with integrations or API clients.
• Data modeling, parsers, or schema-driven conversion.
• Fluent in Python typing with mypy or similar.

Responsibilities

• Design, build, and maintain the software product and libraries.
• Develop a self-service product with actionable errors and predictable behavior.
• Decide what to generalize and what to build next while optimizing cost.
• Own technical initiatives from design to release.
• Coordinate dependencies across teams in writing, not just at integration time.
• Maintain appropriate test coverage and shape testing strategy.
• Apply AI-assisted engineering practices across the SDLC.
• Contribute to architecture as the solution scales.

Skills

Python

AI coding tools

Architectural design

Testing

APIs

Data modeling

Pydantic typing

CI/CD

Asynchronous programming

XML parsing

Go

Observability tooling

Python packaging

Networking concepts

Tools

Docker

Kubernetes

Job description

Get to know us better

CodiLime is a software and network engineering industry expert and the first-choice service partner for top global networking hardware providers, software providers and telecoms. We create proofs-of-concept, help our clients build new products, nurture existing ones and provide services in production environments. Our clients include both tech startups and big players in various industries and geographic locations (US, Japan, Israel, Europe).

While no longer a startup - we have 250+ people on board and have been operating since 2011 we’ve kept our people-oriented culture. Our values are simple:

• Act to deliver.

• Disrupt to grow.

• Team up to win.

The project and the team

You will join a team co-developing a unified network security management platform from a leading cybersecurity vendor. You will be building functionality that automates and facilitates the conversion and onboarding of existing network security estate configurations within that platform.

The solution's foundation rests on several years of experience delivering large-scale migration projects that would not have been possible without specialized automation software. That expertise, together with AI-assisted development, helps the team move fast and consistently land high-quality results.

As the software keeps expanding and becoming a fully-fledged product, we're looking for another Senior Software Engineer to help build what's next. It is as much a product engineering challenge as a technical one.

Other things to know:

• The team consists of software engineers and network security SMEs who share strong ownership of code and product quality

• AI tools are part of the daily workflow

• This is a backend-focused role

• We are a distributed, fully remote team

We work on multiple interesting projects at a time, so it may happen that we'll invite you to an interview for another project if we see that your competencies and profile are well suited for it.

Your role

As a part of the project team, you will be responsible for:

• Designing, building, and maintaining the software product and the underlying libraries

• Building a self-service product: with actionable errors, predictable behavior, and a path a customer can complete without specialized assistance

• Deciding what gets generalized and what gets built once - some capability is shared, some is specific, and keeping that cost curve falling is the central architectural judgment in this role

• Owning and leading technical initiatives to successful delivery, from the design document through to release

• Acting as the technical counterpart to the teams around you - raising dependencies early and in writing, rather than discovering them at integration time

• Maintaining appropriate test coverage and helping shape the overall testing strategy

• Applying AI-assisted engineering practices and setting the standard for how they are used - across the entire SDLC, not only in code generation

• Contributing to architecture and design decisions as the solution scales in different dimensions

• Proposing and helping ship your own ideas for improving the product, beyond your core delivery work

Do we have a match?

As a Senior Software Engineer, you must meet the following criteria:

• Strong, 7+ years professional experience with modern Python - we run 3.14 and stay close to the latest release

• Experience building and maintaining software products for external customers

• Experience owning an architecture end to end, including the part where you align teams you have no authority over

• Hands-on, everyday use of AI coding tools in your engineering workflow, with a considered view of where they earn their keep and where they do not

• Solid testing experience and ability to pick the right testing strategy

• Experience building and maintaining integrations or API clients

• Experience with data modeling and transformation - parsers, intermediate representations, schema-driven conversion or similar

• Fluency with Pydantic and with strict static typing (mypy or equivalent) as a daily discipline

• CI/CD experience

• Comfortable in a fast-paced environment where priorities are set as much by customers as by the backlog

• Open for technical challenges and open-mindedly looking for technical solutions to business problems

• Very good command of English (ideally C1 level) - spoken and written

Beyond the criteria above, we would appreciate the following:

• Experience with workflow or orchestration engines (e.g. Temporal)

• Experience with Docker and Kubernetes

• Experience with SQLAlchemy, or ORM-based data modeling more broadly

• Experience with migration, import or ETL-style tooling

• Experience with asynchronous Python

• Experience with XML at scale, or grammar-based configuration parsing (e.g. TextFSM)

• Experience with Go

• Experience with observability tooling (e.g. OpenTelemetry, Prometheus, Grafana)

• Experience with modern Python packaging and tooling (uv, ruff)

• Working understanding of core networking concepts (TCP/IP, VLAN, NAT, ACL, firewalls, routing)

More reasons to join us

• Flexible working hours and approach to work: fully remotely, in the office or hybrid

• Professional growth supported by internal training sessions and a training budget

• Solid onboarding with a hands-on approach to give you an easy start

• A great atmosphere among professionals who are passionate about their work

• The ability to change the project you work on