Mid-Level BE Engineer

# **Mid-level BE Developer** **What would you work on:** - Deliver complete features end-to-end, from technical breakdown to production, in a microservices platform that handles tens of thousands of requests per minute. - Design your solutions within our existing architecture. You decide how a feature fits together, and you bring in a Senior when the design crosses module boundaries. - Work on real problems of scale: concurrency, high-volume traffic, and availability. - Co-own the health of the services you work in: tests, observability, and the production issues that come with them. - Use AI coding tools as part of your daily workflow, and own the correctness, security, and performance of what they produce. - Review PRs from peers and Juniors, and mentor Juniors informally through pairing and code review feedback. - Break down work, estimate it, and deliver on your commitments. - Be part of a collaborative, autonomous product team in a fast-paced startup environment with no heavy process. **Skills you will need:** - 2+ years of professional experience with Golang (or 3+ years of backend experience with at least 1 year in Go). - A working grasp of how architecture actually works. You do not need to be an architect, but you should be able to look at a design and tell whether it is good or bad, explain why, and make sound decisions inside your own modules. For the bigger calls, you know when to pull a Senior in rather than guess. - Practical experience with concurrent and event-driven systems: goroutines and channels, race conditions, retries, idempotency. - Working knowledge of distributed systems and cloud computing principles. - Experience building microservices using SQL and NoSQL databases, such as PostgreSQL, Redis, and DynamoDB. - Familiarity with API design patterns like gRPC or GraphQL. - Experience running and operating your own code in production on AWS, Azure, or GCP. - Comfortable with Docker; knowledge of Terraform is a plus. - You write and maintain unit and integration tests as part of delivering a feature, not as an afterthought. - Familiarity with Agile development practices. - Interest in esports or traditional sports (a plus!). **Working with AI, required:** We build with AI assistance daily, and we expect you to as well. This is not a “nice to have” line on our list. - **Hands-on experience** with AI coding assistants (Claude / Claude Code, OpenAI Codex, Cursor, GitHub Copilot, or equivalent), and a clear point of view on where they help and where they get in the way. Using them daily on a production codebase is a strong plus. - **You can steer the tools.** You break work into reviewable steps, give the model the context it actually needs (specs, existing code, constraints), and iterate instead of accepting the first answer. - **You know when not to use them.** Some problems are faster and safer written by hand, and you can tell which is which. - **You review AI output like you would review a colleague’s PR**, verifying edge cases, concurrency behaviour, security implications, and performance. You catch hallucinated APIs, outdated patterns, and code that looks plausible but is subtly wrong. - **You own what you merge**, regardless of what generated it. “The model wrote it” is not an explanation for a production incident. - **You know the boundaries:** what can and cannot be shared with an external model, secrets hygiene, and licensing of generated code. - **You share what works.** Effective prompts, patterns, and pitfalls that make the rest of the team faster. Nice to have: experience with agentic workflows, MCP servers, or building internal tooling on top of AI models. **What we are not asking from you:** - Owning cross-team architecture or being the final technical authority. That is what our Seniors are here for. - Designing the platform from scratch. You will work within an architecture that exists, and improve it where it makes sense. *By applying to this position, you consent to Corwyn ABC a.s., id no: **23897953, P**od dráhou 1637/6, Holešovice, 170 00 Praha 7, Czechia, processing your personal data under Regulation (EU) 2016/679.* *Your data will be processed for recruitment and may be retained for up to 3 years for similar job opportunities.* *Rights: Access, correct, delete, restrict, or object to processing; withdraw consent via ; or complain to [](http://www.uoou.cz).* *For more details: Contact [hr@corwyn.com](mailto:hr@corwyn.com) or visit website [here](https://realmsgroup.gg/).*