Jobs Backend

We’re looking for someone who’s good at what they do — and who’s starting to find that being good isn’t the most interesting part anymore.
You’ll own the technical direction of assigned CMS projects, working directly with project leads and US-based clients. The work is real: short feedback loops, actual business impact, people depending on what you build. We think that’s where the most meaningful growth happens.
This is not a management title. It’s a role for someone who can hold their own convictions clearly enough to act — and loosely enough to revise them when the situation asks for it.

What You’ll Do
 

• Own assigned CMS projects end-to-end (primarily WordPress and Drupal)
• Work across multiple projects in parallel
• Advise clients on technology — recommend what’s right for them, not what you’re most comfortable with
• Translate business needs into clear technical options and trade-offs
• Collaborate across disciplines; hold productive tension when perspectives differ
• Learn new frameworks as projects require; contribute to the broader CMS practice
• Pick up complex and simple tasks alike
• Support junior developers through craft, not management
• Contribute beyond project scope — ideas, improvements, initiative

Who You Are
 

• 7+ years in CMS development, strong production WordPress and/or Drupal
• Direct experience with international clients — partnership, not vendor compliance
• English C1+, clear and pleasant spoken communication without a strong accent
• Technology-agnostic — your preferences don’t override the project’s needs
• Comfortable in ambiguity; energized by shifting context
• Entrepreneurial mindset — you treat each project like a business you’re invested in
• Proactive without being pushy
• Able to juggle multiple projects, timelines, and stakeholders
• Willing to start with small steps

Who This Role Probably Isn’t For
We want to be honest about fit — clarity is more respectful than vagueness.
This role may not work well if you need fully defined requirements before you begin thinking, if shifting context drains you rather than energizes you, or if you tend to advocate for your preferred technology stack regardless of what the project calls for.
It’s also probably not the right fit if direct feedback feels like personal criticism rather than useful information. We practice open, respectful communication — we name what we observe, share what we need, and assume good intent. That only works when everyone is willing to hear things they didn’t expect.
None of these are flaws. They’re preferences. But they’d make this environment frustrating rather than enjoyable, and we’d rather be upfront.

Technical Skills

Required:
 

• WordPress, Drupal, Strapi
• React, Next.js
• Docker, AWS (basic)
• SEO, Google Analytics, GTM, Core Web Vitals

Nice to have:
 

• Shopify
• Pantheon.io, WPEngine, or Heroku
• Node.js
• Salesforce integration
• HubSpot integration
• Performance optimization, data migration
• MongoDB, MySQL/MariaDB
• Laravel and/or Symfony
  
  Work Format
   
• Full-time (160 hrs/month). Starting at 0.5–0.75 FTE in the first month with gradual ramp-up. Details discussed during the interview
• Remote-first, async-friendly
• US Eastern Time focus — availability expected between 12:00–20:00 CET
• Multiple projects in parallel, not a single dedicated assignment

What We Offer
 

• At least 2 active long-term projects with gradual, methodical onboarding
• A team that genuinely enjoys working together — serious about the work, light with each other
• Commission structure tied to project profitability. Your growth and the business growth aren’t separate things
• High autonomy. We treat you as an adult — with the freedom and responsibility that comes with that
• Benefits program, internal learning, coaching, English lessons, and therapy compensation after trial period

About Speed & Function
Software development company focused on long-term partnerships, not transactional outsourcing. Since 2006, building digital products and teams with a strong emphasis on trust, ownership, and collaboration.

We are looking for a reliable and experienced PHP Developer with strong CodeIgniter expertise to join our team and work on Perfex CRM

Responsibilities

• Develop and enhance features in Perfex CRM 
• Maintain and improve an existing PHP application built on CodeIgniter
• Understand and work with a complex, already deployed business application
• Implement and maintain integrations via REST APIs
• Collaborate using Git for version control

Requirements

• Strong knowledge of PHP and experience working with existing codebases
• Mandatory hands-on experience with the CodeIgniter framework
• Experience with MySQL / MariaDB
• Solid knowledge of JavaScript (mainly jQuery)
• Good understanding of HTML / CSS
• Basic knowledge of REST APIs and system integrations
• Reliable, detail-oriented, and able to work independently

Nice to Have

• Previous experience with CRM systems or complex business applications

We Offer

• Competitive salary
• Work schedule from 10:00 to 19:00 with a lunch break
• 24 paid vacation days plus public holidays
• Opportunities for professional growth within international projects

Our Client is the Enterprise Worldwide Company. The product you will be working with, provides management and data processing/handling capabilities for networks of the clients scientific lab equipment such as microscopes, etc. The main goals are:

Collection and centralized management of data outputs (measurement results, etc.) provided by clients devices
Outdated data utilization
Managing large volumes of data acquired from measurement devices in the cloud securely and reliably
Seamless sharing of measurement data with collaborators
The ability to share measurement results and accelerate customer service.

Requirements:

• Theoretical knowledge of Java, Spring, Object Oriented Programming, Micro Services
• Theoretical knowledge of SQL 
• Theoretical knowledge of Agile methodologies
• Theoretical knowledge of microservice architecture with event-based communication in the AWS environment – is a plus
• Theoretical knowledge of CI/CD processes – is a plus
• Theoretical Docker knowledge and Kubernetes is a plus
• Self-motivation and self-discipline
• Extensive communication skills, proactivity
• Intermediate English
   

Job responsibilities:

• Absorb practical knowledge and experience
• Ask questions and collaborate
• Participate in the implementation of new features in a highly collaborative environment with the development team
• Participate in backlog decomposition & estimation
• Participate in sprint planning
• Bug Fixing
• Learn how to contribute to a high quality, and performing code base

About the Project

We’re building a cutting-edge AI-powered video platform that aggregates and processes content from multiple social media sources. Users can interact with video data through context-aware search, Retrieval-Augmented Generation (RAG), and LLM agent orchestration.

You’ll join a small, focused team working closely with the CTO/founder, shaping the product’s technical foundation and bringing innovative AI-driven experiences to life.

Tech Stack

Backend: Python (FastAPI), Node.js / TypeScript
Frontend: React, Next.js, Tailwind CSS
Cloud: AWS Lambda, API Gateway, Cognito, S3, DynamoDB, OpenSearch
Architecture: Serverless, event-driven design
AI Integration: RAG, LLM agents, contextual search

Responsibilities

Develop and maintain backend services in Python (FastAPI or similar)
Create and deploy serverless APIs on AWS (Lambda, API Gateway)
Implement secure user authentication (AWS Cognito) and cloud storage (S3)
Integrate AI-powered features (RAG, LLM agents, contextual search)
Parse and process video content and metadata from social media
Implement video display, search, and interaction components
Contribute to infrastructure, CI/CD, and performance optimization

What We’re Looking For

4+ years of professional software development experience
Strong skills in Python (FastAPI preferred)
Proficiency with AWS services (Lambda, Cognito, S3, API Gateway, DynamoDB)
Ability to design and scale RESTful APIs
Understanding of serverless and event-driven architectures
Experience integrating with or building AI/ML-powered features (RAG, LLMs, etc.)
Good communication skills and a proactive, startup-ready mindset

Nice to Have

Experience with React, Next.js, and TypeScript

Experience with video parsing, streaming, or playback
Familiarity with infrastructure-as-code or DevOps (CI/CD pipelines)
Exposure to authentication and analytics systems (AWS Cognito, OpenSearch)
Understanding of SEO, SSR/SSG rendering models in Next.js

Being a part of 3asoft means having

High level of flexibility and freedom
p2p relationship with worldwide customers
Competitive compensation paid in USD
Fully remote working

Required skills

• 5+ years of proven experience in Software development
• Strong knowledge of the Laravel framework
• Deep understanding of SOLID principles, design patterns, and PSR standards
• Experience with SQL (PostgreSQL), query optimization, joins, aggregations
• A clear understanding of TDD, BDD
• Experience with *nix
• Understanding Git versions control system
• A clear understanding of how to write DRY, KISS and optimized for high-load code
• Experience working with the Docker environment, container registry
• Event-driven architecture practical usage
• Experience with Unit tests

• Development workflow knowledge (SDLC)

   

As a plus

• Experience with queues/messaging (Centrifugo) 

   

Must have personal qualities like

• Ability to work in a team
• Good analytical skills and attention to details

• Ability to understand someone else’s code

   

Opportunities

• Build a successful product that grows dynamically within the US market
• Professional and career growth
• Possibility to propose solutions to a project

• Realization of your innovative ideas in building new solutions and services

   

We offer

• Dynamic and challenging technical tasks
• Long-term employment
• Compensation for certifications, conferences, training, and other working events
• Work in a unique professional, friendly and supportive environment
• Informal style of leadership and communication

Reasons to join the team

• Build a successful product that grows dynamically within the US market
• Friendly and open-minded co-workers
• Career development opportunities
• The right tools you need to be successful

A full-lifecycle tech development company dedicated to delivering innovative solutions for the iGaming and gambling industries.
We are building best-in-class applications for the global iGaming market and are looking for a talented Senior Node.js Developer to join our team.

Responsibilities:

• Design, develop, and maintain scalable back-end services using NestJS
• Build and optimize microservice architecture and communication between distributed systems
• Work with PostgreSQL — write performant queries, indexes, views, and materialized views
• Implement Redis for caching and queueing (BullMQ experience is a plus)
• Configure and maintain CI/CD pipelines
• Ensure application security using OAuth and modern client/server security patterns
• Write clean, readable, and maintainable code

Requirements:

• Experience in the iGaming / gambling industry 
• Understanding of iGaming-specific concepts such as game rounds, RTP, RNG, provider integrations, wallet solutions, and transactional flow
• Senior-level experience with Node.js (NestJS)
• Strong knowledge of high-load and real-time processing systems
• Experience with event-driven architecture and message brokers (Kafka, RabbitMQ, BullMQ)
• Experience integrating third-party providers and payment systems

• Deep understanding of transactional flow and microservices architecture

   

Nice to Have:

• Familiarity with Heroku, GCP, and Docker
• Experience with Prisma ORM
• Understanding of scalability and maintainability principles

We power people’s progress.

At Preply, we’re all about creating life-changing learning experiences. We help people discover the magic of the perfect tutor, craft a personalised learning journey, and stay motivated to keep growing. Our approach is human-led, tech-enabled - and it’s creating real impact.

We’ve just reached unicorn status with a $150M Series D, accelerating our vision to transform education through human-led, AI-enhanced learning. Today, 100,000+ tutors teach 90+ languages to learners in 180 countries - and we’re only getting started. As a category-defining company, we’re shaping what the future of learning looks like at global scale.

Every Preply lesson sparks change, fuels ambition, and drives progress that matters. Joining Preply means helping define the future of education at global scale, and building something that truly matters for millions of people, every day.

Meet the team!

We’re on a mission to transform lives through learning. In our Learning Teams, that means building the next generation of personalized, AI-enabled, media-rich experiences for learners and tutors around the world. If you care deeply about impact, quality, technology and culture – this is your chance to lead a part of it.

As a Staff Engineer in the Learning Teams, you will lead some of the most complex and strategic engineering initiatives at Preply. You will define and drive technical roadmaps and architecture, collaborate across product, engineering and business stakeholders, and influence our platform at scale. This is a senior individual contributor role with broad scope and strong impact – you will help shape how we build, ship and evolve our learning experiences globally.

What you’ll be doing

• Shape, drive, and co-own the Learning Teams’s engineering strategy and own technical roadmap, partnering with Engineering and Product Leadership s to align initiatives, priorities and dependencies.
• Lead end-to-end strategic initiatives and innovations, translating high-level product vision into technical execution, align scope and milestones and ship iteratively with measurable outcomes.
• Evolve architecture and core services into a scalable, reliable platform, defining target states, drive deprecations and migrations, and uphold technical excellence (availability, performance, cost).
• Raise engineering practices and developer experience, driving RFCs, post-mortems, quality frameworks (evaluations, instrumentation), identifying bottlenecks and driving initiatives that reduce toil and increase productivity across team
• Operate as a multiplier: mentor and influence senior engineers, Tech Leads, EMs, and hiring panels; stay hands-on for the hardest, most impactful work.
• Make build-vs-buy and vendor/tooling calls with a clear view of total cost of ownership; lead evaluations and participate in negotiations.

What you'll bring

• Strong foundation in software engineering and architecture; comfortable designing and evolving large-scale systems and deriving technical strategy from business objectives.
• Proficiency across the full stack, from frontend frameworks and mobile clients to backend systems, APIs, and data flows, with a focus on cohesive end-to-end experiences.
• Hands-on technical expertise, comfortable diving deep into code, building proofs-of-concept, and iterating quickly with teams to validate technical approaches.
• Excellent communication and leadership skills, able to articulate technical vision, trade-offs, and business value to both engineering, product and executive stakeholders. Able to influence without formal authority.
• Proven track record of taking ownership end-to-end, from defining scope, through delivery, launch, and operational stability.
• Analytical and creative problem-solving skills, able to explore multiple implementation paths, evaluate trade-offs, and make pragmatic decisions under uncertainty.
• Ability to operate across domains, new feature development, architecture evolution, system migrations, process improvement – all matters.
• Proven experience driving engineering culture, mentoring senior engineers, influencing tech leads, leading hiring for key roles, establishing and evangelising RFCs, post-mortems, etc.

• Experience or strong interest in one or more of these domains: AI/ML, media/video platforms, large-scale system migrations, cost optimisation, data infrastructure, QA/test-automation at scale.

   

Why you’ll love it at Preply:

• An open, collaborative, dynamic, and diverse culture;
• A generous monthly allowance for lessons on Preply.com, Learning & Development budget, and time off for your self-development;
• A competitive financial package with equity, leave allowance, and health insurance;
• Access to free mental health support platforms;
• The opportunity to unlock the potential of learners and tutors through language learning and teaching in 175 countries (and counting!)

Description

A program of projects within the Energy domain. We will work on various applications covering generation control, distribution control, transmission control, and service crews control. The implementation area of these products is very high-scale (e.g. country-wide systems).

Job Description

• 5+ years of experience as .Net developer. At least 2 years as a Lead developer
• Ability to lead a team of 4-6 engineers
• Proven experience in working with teams/solution architects/ POs from the client-side
• Goog grasp of the application architecture.
• Proven experience with Azure, Azure DevOps
• Proven experience with both desktop and cloud-based applications
• OOP Development, Design Patterns, Best Practices
• Good English to work with clients directly

Job Responsibilities

• Strong problem-solving and follow-up skills; must be proactive and take initiative
• Professionalism and the ability to maintain the highest level of confidentiality
• Create robust solutions and translate project requirements into application architecture decisions
• Lead the development process using development and security best practices
• Leverage technologies to support business needs to attain high reusability and maintainability of current and newly developed solutions
• Provide system design recommendations based on technical requirements
• Work independently on the tasks and ensure the team's supervision
• Ensure high-quality software delivery and code quality by utilizing tools such as SonarCloud or Black Duck.  
• Leads a team of engineers and AQAs to work on the team backlog, support Scrum Master and PO

We power people’s progress.

At Preply, we’re all about creating life-changing learning experiences. We help people discover the magic of the perfect tutor, craft a personalised learning journey, and stay motivated to keep growing. Our approach is human-led, tech-enabled - and it’s creating real impact.

We’ve just reached unicorn status with a $150M Series D, accelerating our vision to transform education through human-led, AI-enhanced learning. Today, 100,000+ tutors teach 90+ languages to learners in 180 countries - and we’re only getting started. As a category-defining company, we’re shaping what the future of learning looks like at global scale.

Every Preply lesson sparks change, fuels ambition, and drives progress that matters. Joining Preply means helping define the future of education at global scale, and building something that truly matters for millions of people, every day.

We power people's progress.

At Preply, we’re all about creating life-changing learning experiences. We help people discover the magic of the perfect tutor, craft a personalized learning journey, and stay motivated to keep growing. Our approach is human-led, tech-enabled - and it’s creating real impact. So far, 90,000 tutors have delivered over 20 million lessons to learners in more than 175 countries. Every Preply lesson sparks change, fuels ambition, and drives progress that matters.
 

Meet the team!

Join Preply’s Teams and help us power people’s progress through life-changing learning experiences. We’re on a mission to combine the magic of the best tutors with cutting-edge AI to create personalized journeys that keep learners motivated and inspired. The Preply Engineering Team provides the tools to help unlock human potential through learning.

Our team builds scalable, resilient applications using the powerful combination of Python/Django on the backend and ReactJS on the frontend — all to deliver an exceptional, seamless experience to our users.

We’re proudly tech-agnostic, meaning we’re open to candidates with a variety of technical backgrounds, whether that’s Java/Spring, Node.js/Express, Ruby on Rails, Scala/Play, PHP, or Golang.

While Python is our main language, prior experience with it isn’t required. What matters most is your willingness to learn, your ability to adapt quickly, and your enthusiasm for using Python in product-focused development.

We implement A/B tests to prove the value of our initiatives and improve our product based on data and students' and tutors' feedback. As part of our commitment to ensuring high-quality products, we prioritize monitoring and metrics analysis to identify areas for optimization and ensure our services are performing at their best. 

At Preply, we release our product 50-60 times per day by leveraging top-notch CI/CD processes. As a fast-growing company we have diverse technical challenges (sometimes we even write about them on our Engineering Blog) that will allow you to develop your skills at scale. 

What you’ll be doing:

You will work in a cross-functional team alongside the Product Manager, Product Designer, UX Writers, Data Analytics, Technical Leads, Engineers and other cross-functional team members to deliver engaging features through A/B tests and build top-notch products, including, but not limited to:

• Develop and own backend features using Python/Django, supporting the creation of new backend services as well as design, create, and/or troubleshoot integrations with third-party vendors.
• Think beyond the code and about our customers, understand their needs, and define solutions with the team;
• Balance short-term speed of development with the long-term technical quality of our systems;
• As a Senior Engineer, you will leverage your experience to guide the team in making informed technical decisions, such as continuous improvement of best practices (test culture, code reviews, monitoring and scalability of our tools). 

What you need to succeed:

• Exposure to architectural patterns of a large, high-scale web application (e.g., well-designed APIs, high-volume data pipelines, efficient algorithms);
• Familiar and willing to support small JS/TS tasks when needed;
• Expertise in troubleshooting issues, identifying the root cause, mitigating it, and setting up safeguards to prevent future issues;
• High level of self-organization, ownership, and responsibility;
• A great collaborator with excellent verbal and written communication skills. Minimum B2 English level;
• Willingness to be on-call for your squad (1 week every 5 weeks).

Why you’ll love it at Preply: 

• An open, collaborative, dynamic, and diverse culture;
• A generous monthly allowance for lessons on Preply.com, Learning & Development budget, and time off for your self-development;
• A competitive financial package with equity, leave allowance, and health insurance;
• Access to free mental health support platforms;
• The opportunity to unlock the potential of learners and tutors through language learning and teaching in 175 countries (and counting!)

We are looking for a Python Developer to join our team.
The role involves working with high-load systems, contributing to architectural decisions, and building scalable backend services.
 

Responsibilities

- Design, develop, and maintain REST APIs using FastAPI / Flask

- Participate in backend architecture design for high-load systems

- Work with AWS services: Lambda, S3, API Gateway, EventBridge 

- Design databases and optimize complex queries
(PostgreSQL, DynamoDB)

- Data validation using Pydantic, performance optimization

- Implement logging, error handling, and testing

- Participate in code reviews and technical discussions

- Collaborate closely with the team on backend-related decisions
 

Requirements:

- 3+ years of commercial experience with Python

- Strong backend-focused experience

- Python 3.x

- FastAPI / Flask, Pydantic

- Hands-on experience with AWS (Lambda, S3, API Gateway, EventBridge)

- Solid knowledge of PostgreSQL / SQL

- Understanding of REST API principles

- Git, experience working in a team

- Experience working with high-load systems
 

Nice to have

- Docker, CI/CD pipelines

- Terraform

- Redis / caching

- Async Python

- Experience with scalability and backend performance optimization

Backend Engineer (Location-Based Mobile Game / AR)

About the Project
 

We are building a location-based mobile game where users purchase keys to hunt and open real-world chests using their phone camera.

Each chest can be opened only once globally, which makes backend logic, geo-queries, and data integrity critical.

This is an early-stage MVP with clear scope, fast decisions, and direct access to the product owner.

Responsibilities

• Design and implement backend architecture for the MVP
• Build REST APIs for:
   
  • user profiles & authentication
  • keys inventory & balance
  • geo-based chest discovery
  • chest opening (atomic, server-authoritative)
  • town-based statistics & leaderboard
     
• Design PostgreSQL schema with geospatial queries (PostGIS)
• Implement anti-cheat logic:
   
  • distance validation
  • speed / teleport detection
  • race-condition protection (two users opening same chest)
     
• Integrate Apple / Google sign-in
• Support in-app purchase receipt validation (keys)
• Work closely with Unity developer to define clean API contracts
   

Technical Requirements (Must Have)

• 4+ years of backend development experience
• Strong knowledge of PostgreSQL
• Experience designing REST APIs
• Understanding of transactional systems & data consistency
• Experience with Node.js (NestJS) or Go
• Familiarity with authentication flows (OAuth)
• Ability to work independently and make technical decisions
   

Nice to Have

• Experience with PostGIS or geo-based queries
• Experience with mobile games or high-concurrency systems
• Understanding of anti-fraud / anti-cheat patterns
• Experience with cloud deployment (AWS / GCP / similar)

What This Is NOT

• This is not a large corporate project
• No heavy bureaucracy
• No 10-layer approval process
• You will not “just implement tickets” — you will shape the system
   

Engagement Format

• Full-time preferred
• Remote
• Direct communication with founder / product owner

Company Description

Are you ready to take ownership of mission-critical backend systems in a high-load, transaction-heavy environment? We are looking for a Senior Java Developer to join our Payments Domain team in Warsaw.

This is a hybrid role with 3 days per week in the office, giving you the perfect balance between collaboration and flexibility. At Sigma Software, we value engineering excellence, multicultural teamwork, and delivering secure, high-performance solutions.

Why join us? You’ll work on a platform processing millions of transactions daily, contribute to architectural decisions, and be part of a company where innovation and ownership are encouraged.

CUSTOMER

Our customer is a well-established international company in the iGaming industry, known for its engineering-driven culture and multicultural team distributed across multiple countries. Operating multiple brands across various markets, the company delivers secure, high-performance digital platforms recognized for reliability and scalability.

PROJECT

You will be part of the Payments Domain team, responsible for developing and maintaining a large-scale payments platform built on modern microservices architecture. The platform processes millions of secure transactions daily, supporting multiple brands and geographies. The work focuses on scalability, reliability, and performance in a high-load environment, covering everything from integration with payment providers to transaction monitoring and compliance.

Job Description

• Design, develop, and maintain backend services for the payments platform using Java and Spring Boot
• Ensure high availability, scalability, and performance of transaction processing systems
• Collaborate with cross-functional teams to define technical requirements and deliver solutions end-to-end
• Implement integrations with payment service providers and internal systems
• Participate in architectural discussions and contribute to system evolution in a microservices environment
• Monitor, troubleshoot, and optimize services in production
• Ensure compliance with security, regulatory, and operational standards
• Drive continuous improvement in code quality, testing, and deployment practices
• 3 days per week working from the office

Qualifications

• 5+ years of commercial experience with Java and Spring Boot
• Strong experience with MySQL and Kafka
• Proven track record working with microservices architecture in high-traffic, high-load systems
• Experience developing high-performance backend solutions for transaction-heavy platforms
• Ownership mindset with ability to deliver services end-to-end
• Excellent communication skills in English (C1 level), both written and verbal
• Experience with Kotlin

The primary goal of this position is to develop and maintain the backend infrastructure of our main website millanova.com, including custom Strapi plugins, search engine integration, payment processing, and database optimization.

Tech Stack: Strapi v4 (Node.js), TypeScript, PostgreSQL, GraphQL, Meilisearch, Stripe, React (Admin UI), SendGrid, Docker

Responsibilities:

• Design and develop custom Strapi plugins (local packages) to extend platform functionality.
• Integrate and configure Meilisearch for fast, intelligent, and relevant search capabilities.
• Implement and manage Stripe payment processing on the backend (transactions, webhooks, error handling).
• Customize the Strapi admin panel using React and Monaco Editor (custom providers, editors).
• Maintain and optimize the PostgreSQL database; write efficient raw SQL queries.
• Develop and optimize GraphQL API endpoints for performance and reliability.
• Integrate third-party APIs, collect external data, and persist it to the database.
• Build standalone Node.js microservices from scratch and deploy them in Docker containers for automated data synchronization.
• Collaborate closely with the frontend team to ensure seamless integration and data flow.

Requirements:

• 2+ years of commercial experience with Node.js and TypeScript.
• Hands-on experience with Strapi v4 (deep understanding of its internals, custom providers, and plugin architecture).
• Deep proficiency in PostgreSQL: schema design, query optimization, and writing raw SQL.
• Experience with GraphQL (building and optimizing queries/mutations).
• Familiarity with Meilisearch or similar search engines (Elasticsearch, Algolia).
• Experience integrating payment systems (Stripe API preferred).
• Confident knowledge of Docker for containerization and deployment.
• Experience with email services (SendGrid or similar).
• Strong backend performance optimization skills (SQL tuning, caching, query profiling).
• Ability to work collaboratively with frontend developers and cross-functional teams.

Would be a great plus:

• Experience with e-commerce backend systems.
• Previous work with CMS customization beyond standard configuration.
• Experience building microservices architecture.
• Knowledge of CI/CD pipelines and deployment automation.

What do we offer:

• Long-term project with a modern tech stack.
• Hybrid & flexible schedule.
• Regular performance reviews.
• Paid vacation (18 days).
• Direct ability to influence the product architecture.
• Collaborative team environment with close backend-frontend interaction.

Hiring process:

• HR and Technical interview (focus on Node.js, Strapi, PostgreSQL, and system design).
• Offer.

Responsibilities

• Design and develop a data scraping system (web crawling, parsing).
• Optimize tools for data collection and aggregation.
• Build ETL/ELT pipelines.
• Work with unstable or complex data sources.

Requirements

• Expert in Python.
• Experience with asynchronous programming (asyncio, Celery, etc.).
• Secure data processing and serialization (JSON, MessagePack, Protobuf).
• Experience with PostgreSQL, MySQL, or NoSQL (MongoDB).
• Secure coding principles: input validation, avoiding injection attacks.
• Building secure internal APIs (not necessarily web-facing).
• Experience with Docker, Kubernetes, and secure container deployment.
• Familiarity with Linux hardening and secure configuration.

Nice to Have

• Practical experience with data mining.
• Knowledge of scraping libraries: Scrapy, Requests, Selenium/Playwright, or equivalents.

Hello.

We are looking for a Middle+/Senior Node.js Developer to join Ohayu (https://ohayu.com). We are building the easiest way for travelers to stay online anywhere in the world. We’re a fast-scaling B2C mobile + web app (iOS/Android/Web) that lets people buy eSIM data plans in minutes - cheaper than roaming, no SIM shops, no hassle. Thousands of travelers already use Ohayu worldwide, and we’re just getting started.
Our ambition is bigger than eSIM: we’re evolving Ohayu into a full Travel App that makes every journey smoother.

What you’ll do:

This role is for someone who wants real ownership and real product impact.

• Own integrations with third-party APIs (telco/eSIM providers, payments, analytics, etc.) - abstraction layers, reliability, observability, edge cases, scale.
• Shape backend direction: architecture decisions, technical standards, and how we build/ship safely at speed.
• Enable rapid experimentation: implement backend changes for A/B tests and product iterations that directly impact conversion and retention.
• Build and maintain production-grade services: migrations, logging, alerts, uptime, and smooth releases.

What we’re looking for:

• 5+ years of backend with OOP experience
• 5+ years with Node.js + TypeScript
• 2+ years with NestJS
• 5+ years with MySQL / MariaDB / PostgreSQL
• Hands-on production experience: migrations, monitoring/logging, alerts, process managers (pm2/supervisor), incident mindset
• You work independently, communicate clearly, and take responsibility end-to-end
• At least intermediate English level (all work communication is in English)

Nice to have:

• Experience with high-load systems
• Experience supporting A/B testing and experimentation platforms/pipelines

Why to join us:

• Direct product impact: what you ship gets used immediately by real travelers.
• Ownership: you’re not “a contributor,” you’re a builder helping set the backend direction.
• Product engineering culture: we care about UX and conversion as much as we care about clean code.
• Fast pace, real learning: constant iterations, clear feedback loops, real-world constraints.
• Genesis ecosystem: access to strong expertise, resources, and networking.
• Benefits: health insurance, 20 paid vacation days, annual performance review with clear salary progression.

Work format: Possibility to work fully remotely or from our offices in Warsaw, Kyiv or Lviv.

Join us in reshaping the future of connectivity.