Skip to content
Backend Engineer

Backend Engineer

Senior Java Software Engineer

Tenarai Europe

Cracow

Apply on the employer's site

Role description

Project info:

We are currently looking for an experienced professional with strong technical skills and a quality mindset to join our development team. The team is responsible end-to-end for the development, testing & support of a widely used Software Development Kit which enables thousands of developers around the world to create apps deployed to over 250,000 end users worldwide. Our development process is based on Agile principles with a strong focus on continuous integration and continuous delivery. Quality assurance work is mainly concentrated on test automation: creating test scripts for Java APIs, Typescript APIs, Java & Web UI and web services. If you are looking for a challenging and innovative project using modern technologies, then this place is for you.

Responsibilities:

  • Design, develop, test and maintain backend applications using Java and Spring Boot.
  • Build and support RESTful APIs and gRPC services.
  • Develop solutions deployed on Google Cloud Platform (GCP) and Kubernetes.
  • Collaborate with QA, SRE, and Product teams.
  • Participate in CI/CD processes, deployments, and production support.
  • Provide support during release cycles, including smoke testing, manual validation.
  • Troubleshoot issues using logs, metrics, and monitoring tools.
  • Conduct code reviews, mentor junior developers, and participate in an on-call rotation.

Requirements:

  • 6+ years of experience with Java and Spring Boot.
  • Experience building microservices, REST APIs, and gRPC services.
  • Hands-on experience with GCP, Docker, and Kubernetes.
  • Knowledge of GitHub, Jenkins, or GitHub Actions.
  • Familiarity with monitoring tools such as Prometheus and Stackdriver/Cloud Monitoring.
  • Basic scripting skills in Python or Bash.
  • Experience with WireMock and performance testing.
  • Hybrid work setup (2–3 days a week from the Krakow office, working in the CET time zone)

Must possess a legal work permit in Poland

Benefits:

General benefits - depends on the form of employment

  • Hybrid work model combining office & remote work
  • Attractively located office with collaboration spaces
  • Onsite parking space for employees
  • Referral program with financial bonus
  • Life Insurance
  • Budget for development (including language courses and others), clear career path with the possibility to gain experience in international environment
  • Access to internal Learning Platform with multiple trainings oriented for professional growth

Lifestyle benefits:

  • Access to MyBenefit platform (Multisport included)
  • Team Building activities
  • Charity initiatives
  • Working environment promoting diversity and inclusion

Health benefits:

  • Private medical care - Platinum Package

This is a saved copy of a posting published elsewhere. Postings get taken down without notice — check the employer's site before applying. mentors.coach is not the hiring party.

Coming to this page

A resume for this role — and a ticket to the draw

We take the posting apart down to the real requirements and rewrite your resume against it — by asking, not inventing: no line appears without your confirmation. Sign in to get it first, and to enter the draw.

  • A resume for this exact role, not a universal one
  • Answers are kept: edit any one, not the whole conversation
  • All in your account — open it from any device

On the wheel

A discount on mentoring

Winners are drawn at random among entries with a confirmed email. The date and the full rules are on the draw page.

Draw rules

Backend Engineer

Senior React Native Developer

Ruby Labs

Remotefulltimesenior

Apply on the employer's site

Role description

About Us
Ruby Labs is a leading tech company that creates and operates innovative consumer products. We offer a diverse range of opportunities across the health, education, and entertainment industries. Our innovative teams are driving the future of consumer-led products, and we're always looking for passionate individuals to join us. Learn more about our story at: https://rubylabs.com/about\-us/

About The Role
At RubyLabs we’re looking for a
Senior React Native Developer
to join our growing engineering team and help lead our expansion into mobile. This is a role for someone who cares deeply about product quality, enjoys solving architectural challenges, and wants ownership over real features that users rely on.

You’ll play a key role in building and scaling our mobile applications, shaping the future of our mobile offering, and collaborating closely with backend and product teams to deliver a seamless, reliable, and high-performance user experience.

Key Responsibilities

  • Contribute to the development and delivery of new mobile product features.
  • Maintain and improve the existing React Native codebase, performance, and stability.
  • Define and evolve mobile architecture, system design, and technical strategy.
  • Partner with backend, product, and design teams to shape solutions that scale.
  • Drive reliability, performance, and observability standards on mobile.
  • Own production debugging, incident investigation, and root cause analysis.
  • Guide improvements in build systems, CI/CD, releases, testing, and app store deployments.
  • Support hiring and help grow a world-class mobile engineering team.
  • Champion performance across rendering, navigation, latency, memory, offline behavior, caching, and real-time experiences.

Qualifications

  • 5+ years of experience building mobile applications, with significant React Native experience.
  • Experience mentoring engineers through code reviews, architecture, and incident response is a strong plus.
  • Strong understanding of mobile system design, component architecture, state management, navigation patterns, and performance trade-offs.
  • Experience optimizing UI performance, memory usage, rendering efficiency, and startup time.
  • Deep knowledge of React internals and rendering behavior (hooks, reconciliation, lifecycle, render cost).
  • Experience working with native modules and iOS/Android bridging.
  • Shipped and maintained apps on the App Store and Google Play.
  • Experience with CI/CD, builds, release automation, and OTA updates (EAS, CodePush, or similar).
  • Experience implementing monitoring and observability (Sentry, OpenTelemetry, crash reporting, performance tracing).
  • Demonstrated ownership of edge cases, distributed failure modes, degraded APIs, offline sync, and recovery UX.
  • Demonstrated ability to lead architecture or technical strategy for a mobile app or major feature.
  • Maintains high standards for clean code, SOLID principles, maintainability, and documentation.

Nice to have

  • Experience in startup or high-ownership product teams.
  • Experience scaling real-time or multi-region mobile architectures.
  • Experience designing or building design systems, shared component libraries, or mobile platform foundations.
  • Experience improving mobile security, analytics, performance profiling, and release automation.
  • Knowledge of edge caching, streaming real-time events, WebSockets, or offline-first architectures.

Location
Ruby Labs operates within the CET (Central European Time) zone. Applicants from any country are welcome to apply for the position as long as they are located within approximately ± 4 hours of CET. This ensures optimal collaboration and communication during working hours.

Benefits
Discover the perks of being part of our vibrant team! We offer:

  • Remote Work Environment: Embrace the freedom to work from anywhere, anytime, promoting a healthy work-life balance.
  • Unlimited PTO: Enjoy unlimited paid time off to recharge and prioritize your well-being, without counting days.
  • Paid National Holidays: Celebrate and relax on national holidays with paid time off to unwind and recharge.
  • Company-provided MacBook: Experience seamless productivity with top-notch Apple MacBooks provided to all employees who need them.
  • Flexible Independent Contractor Agreement: Unlock the benefits of flexibility, autonomy, and entrepreneurial opportunities. Benefit from tax advantages, networking opportunities, reduced employment obligations, and the freedom to work from anywhere. Read more about it here: https://docs.google.com/document/d/1nkrN76JlZkbKj9WSOhlT1\_mni\_CZeDkHdwfIjPXVwvk/preview?tab\=t.0\#heading\=h.ndsdl4wapxtt

Be part of our fast-growing team and seize this excellent opportunity for personal and professional growth!

Interview Process
After submitting your application, we conduct a thorough review which typically takes 3 to 5 days, but may occasionally take longer due to the volume of applications received. If we see a potential fit, we proceed with the following steps:

  • Recruiter Screening (40 minutes)
  • Technical Interview (90 minutes)
  • Final Interview (60 minutes)

Life at Ruby Labs
At Ruby Labs, we move fast, aim high, and expect the same from our team. We’re not here to play small—we’re here to build, grow, and win. That means we look for people who are ambitious, driven, and ready to give their best every single day.

This is a place for individuals who thrive under pressure, embrace challenges, and see opportunity in every obstacle. If you’re hungry to achieve, motivated by impact, and want to grow at the speed of your own ambition, Ruby Labs offers the platform to make it happen.

Here, effort is matched with reward. We recognize those who go all in and deliver results, and we create space for people who want more—more responsibility, more growth, and more success.

This is a saved copy of a posting published elsewhere. Postings get taken down without notice — check the employer's site before applying. mentors.coach is not the hiring party.

Backend Engineer

JavaScript/TypeScript Developer - Remote

YO IT Consulting

Remotefulltime

Apply on the employer's site

Role description

Job Title:
Software Engineering

Job Type:
Contractor (10-12 hours per week)

Location:
Remote

Job Summary
We are looking for experienced software engineers to help train and evaluate next-generation AI systems through real-world software engineering tasks. This role is best suited for developers who can reason through unfamiliar codebases, explain engineering decisions clearly, and solve practical backend, full-stack, systems, or infrastructure-related problems.

No prior AI experience is required. What matters most is strong software engineering judgment, clean technical communication, and the ability to evaluate code, architecture, tradeoffs, and implementation quality.

Key Responsibilities

  • Work on challenging software engineering tasks across backend, full-stack, infrastructure, and systems-related projects.
  • Review, debug, improve, and explain code across different technical environments.
  • Design or evaluate practical solutions involving APIs, databases, services, integrations, testing, and deployment workflows.
  • Identify tradeoffs around scalability, maintainability, performance, reliability, security, and developer experience.
  • Communicate technical reasoning clearly in writing, including why a solution works and what alternatives were considered.
  • Collaborate with the customer’s team on technical reviews, implementation decisions, and problem-solving exercises.
  • Adapt quickly to new codebases, frameworks, and technical requirements.

Required Skills And Qualifications

  • 5+ years of hands-on software engineering experience.
  • Strong experience in at least one backend or full-stack engineering environment, such as Python, JavaScript/TypeScript, Node.js, Java, C#, .NET, C++, Go, Ruby, PHP, or similar.
  • Experience building, maintaining, or reviewing production-level applications, APIs, services, databases, or integrations.
  • Strong understanding of software engineering fundamentals, including debugging, testing, code quality, architecture, and technical tradeoffs.
  • Ability to explain complex engineering decisions clearly and objectively.
  • Comfortable reading and reasoning through unfamiliar code or technical requirements

Preferred Qualifications

  • Experience with cloud environments such as AWS, GCP, or Azure.
  • Experience with CI/CD pipelines, DevOps workflows, containers, monitoring, or production operations.
  • Experience with frontend frameworks such as React, Next.js, Angular, Vue, or React Native.
  • Open-source contributions, public GitHub work, technical writing, or strong examples of past engineering work.
  • Experience mentoring engineers, reviewing code, or making architecture decisions.

This is a saved copy of a posting published elsewhere. Postings get taken down without notice — check the employer's site before applying. mentors.coach is not the hiring party.

Backend Engineer

Node.Js Developer - Remote

YO IT Consulting

Remotefulltime

Apply on the employer's site

Role description

Job Description
Job Title:
Node.Js Developer

Job Type:
Contract

Location:
Remote

Job Summary:
In this role, you'll apply your expertise to help train next-generation AI systems. Your work will shape how models learn, reason, and perform through high-quality, real-world input. No prior experience in AI is required — your domain knowledge is what matters.

Key Responsibilities

  • Leverage your deep knowledge of Node.js, JavaScript, and TypeScript to provide expert-level input and feedback for AI system development.
  • Analyze and review code samples to ensure accuracy, efficiency, and adherence to best practices.
  • Collaborate with multidisciplinary teams to identify key development patterns and problem-solving strategies in backend engineering.
  • Evaluate real-world Node.js scenarios to help models learn robust, scalable, and maintainable solutions.
  • Document insights, edge cases, and nuanced technical considerations in clear, effective written form.
  • Contribute to model training by communicating complex concepts in a way that's accessible for both technical and non-technical stakeholders.
  • Uphold high standards of written and verbal communication with both internal and external partners.

Required Skills And Qualifications

  • Extensive hands-on experience with Node.js, JavaScript, and TypeScript in professional environments.
  • Expert problem-solving and debugging abilities within distributed application systems.
  • Strong attention to detail in both code review and written documentation.
  • Excellent written and verbal communication skills, with an emphasis on clarity and thoroughness.
  • Deep understanding of backend application architectures and common development patterns.
  • Demonstrated ability to analyze and articulate technical trade-offs and solutions.
  • Proactive, collaborative approach to cross-functional teamwork.

Preferred Qualifications

  • Prior experience contributing to AI-related projects or model training initiatives.
  • Background in designing or maintaining large-scale, high-availability Node.js applications.
  • Experience with remote collaboration and asynchronous communication tools.

This is a saved copy of a posting published elsewhere. Postings get taken down without notice — check the employer's site before applying. mentors.coach is not the hiring party.

Backend Engineer

Backend C# Developer (.NET + AI-Assisted Development)

Smart Apartment Data

Remotefulltimelead

Apply on the employer's site

Role description

Remote | Eastern Europe Only

USD $3,000-3,500/month

About Us
We're a profitable, U.S.-based technology company with over 20 years of experience building data-driven software for the real estate and analytics industry.

Our engineering team values practical problem solving, clean architecture, ownership, and continuous improvement. We work remotely, move quickly, and embrace modern development practices—including AI-assisted software engineering.

About The Role
We're looking for a Backend C# Developer who enjoys building reliable, scalable backend systems and uses modern AI development tools to improve productivity without compromising code quality.

You'll develop APIs, backend services, and data-processing applications while collaborating closely with experienced engineers in a fast-moving remote environment.

This role is ideal for someone who combines strong backend fundamentals with an AI-first engineering mindset.

What You'll Do

  • Build and maintain backend applications using C# and .NET
  • Design and develop scalable REST APIs
  • Optimize SQL Server databases and application performance
  • Troubleshoot production issues and deliver reliable solutions
  • Use AI development tools (e.g., Cursor, Claude Code, GitHub Copilot, ChatGPT) to accelerate development while maintaining high code quality
  • Collaborate with engineers to deliver clean, scalable, and maintainable software

Sneak peek of projects:

  • Big Data Orchestration
  • Data Warehousing in SQL Server & NoSQL
  • API Design with C# 13 / .NET 9

Requirements
What We're Looking For

  • Minimum 2 years of professional C#/.NET development experience
  • Good written and spoken English
  • Strong experience building REST APIs
  • Solid SQL Server and relational database skills
  • Experience debugging and maintaining production applications
  • Regularly uses AI development tools (e.g., Cursor, Claude Code, GitHub Copilot, ChatGPT) to improve development productivity while maintaining code quality
  • Able to work independently in a remote environment

Nice to Have

  • Experience with Azure
  • Experience with Docker and CI/CD pipelines
  • Entity Framework
  • Experience integrating AI or third-party APIs

Benefits
We offer:

  • Location Independent / 100% Remote
  • $3000-$3500 USD/month
  • Long-term opportunity with a stable U.S. technology company
  • Exposure to modern backend architecture and AI-assisted software development

This is a saved copy of a posting published elsewhere. Postings get taken down without notice — check the employer's site before applying. mentors.coach is not the hiring party.

1,188 more openings in this category and country

Senior Java Software EngineerTenarai Europe

Apply on the employer's site
Senior Java Software Engineer — Tenarai Europe | mentors.coach