Senior Backend Engineer (Node + Java)

Designing systems, not just writing endpoints

We’re looking for a backend engineer who thinks in systems, understands business domains, and treats AI as a tool -> not a threat.Node.js and Java are important, but they’re means, not the goal. What matters most is architecture, decision-making, and ownership. This role also involves shaping solutions early -> translating business needs into technical architectures and supporting technical decision-making before a single line of code is written.

At first glance, some of the points below may sound generic or even like buzzwords. They aren’t.

Every item in this description is here intentionally and reflects how we actually work and what we expect from this role.

What you’ll do:

• Design and build API-first, event-driven backend systems that power mobile applications used by millions — apps you may already have on your phone

• Create backend-for-frontend (BFF) layers for mobile apps operating at real scale, with real performance and reliability constraints

• Work across Node.js and Java on large, well-known products and long-lived systems, not only early-stage startups

• Work directly with clients and product teams to shape solutions — understanding constraints, trade-offs, and business goals, not just implementing tickets

• Shape solutions early and participate in technical presales, including architecture proposals, estimations, and technical validation

• Make and communicate architectural decisions considering scalability, reliability, security, and cost, from presales through delivery

• Use third-party services, cloud platforms, and APIs to simplify systems and deliver value faster — choosing build vs buy consciously

• Work in a team that uses AI thoughtfully and seriously, investing in it to stay competitive in 2030, not stuck in how software was built in 2020

Tech & architecture we work with:

Architecture

• Monoliths and microservices, event-driven systems

• REST / GraphQL / streaming APIs (event streams, real-time data, AI token streaming)

• Kafka / RabbitMQ / async messaging

• Making architectural trade-offs: serverless vs long-running services, build vs buy, split vs keep together

Nodejs / Java

• Backend-for-Frontend (mobile-first) - API shaping, versioning, performance for mobile clients

• External APIs & third-party services - integrations, auth, rate limits, failure handling

• Real-time & streaming - WebSockets, event streams, AI/LLM token streaming

• Data & persistence - SQL and NoSQL databases, schema and query design

• Choosing technologies based on system constraints, scale, domain complexity, and long-term ownership

Platform & cloud

• Cloud platforms (AWS) - compute, storage, networking, managed services

• Managed over custom - databases, queues, caches, third-party platforms

• Kubernetes and/or serverless - understanding trade-offs

• CI/CD - build, test, deploy pipelines

• Observability - logs, metrics, tracing

• Performance & cost - treated as engineering concerns

• DevOps collaboration - or ability to handle much of it independently

Security

• OAuth2 / OIDC / JWT

• Security-by-design fundamentals

• Awareness of compliance constraints in regulated domains (e.g. finance, healthcare)

Requirements:

Technically

• You think architecturally, not just implementation-first

• You constantly ask yourself “can this be done differently or better?”

• You stay curious about new tools, platforms, and approaches

• You can review, challenge, and improve AI-generated code

• You understand trade-offs: time vs quality vs cost vs risk

• At least 4 years of commercial experience, including projects with significant change and ambiguity — and at least one you can confidently walk us through end-to-end

Soft skills

• You communicate well with product, UX, frontend, and clients

• You take ownership: when you join a project, you care about its outcome

• You don’t wait to be told what to do -> you proactively suggest improvements

• You like to represent the technical perspective in client discussions and internal decision forums

• You see yourself as part of the system, not just someone executing tasks

• You care about understanding the business domain behind the software

How we work with AI

• AI is a core part of our workflow, not an experiment

• You’ll get tools, access, and support to use AI effectively

• AI is used not only for coding, but also:

  • during discovery

  • when shaping requirements

  • when reviewing and evolving solutions

• Your work is continuously reviewed:

  • by humans

  • and by AI-based tools

• AI does not replace engineers -> it works alongside them, including you

  
  

This role is probably not for you if:

• You prefer to build everything yourself instead of using proven third-party services

• You only want to implement predefined tasks

• You avoid architectural responsibility

• You’re not comfortable with AI influencing how software is designed and reviewed

We value your trust in providing us your data, thus we are striving to use commercially acceptable means of protecting it. Below you will find the necessary information about the data we collect and process when you send us your CV.

The controller of your personal data is Miquido Spółka z ograniczoną odpowiedzialnością sp. k. with its seat in Krakow, Zabłocie 43a, 30-701 Kraków, Poland (“Miquido”, “We”, “Our” or “Us”). See more