Jobs Backend

We are looking for 2–3 Senior C#/.NET Developers (2–3 FTE) to join a project for a client from Finland, focused on the development of Loyalty APIs.

📍 Work model: 100% Remote

🌍 Eligible location: Poland (candidates must be based in Poland)

🗣️ Language: English C1

📅 Start date: ASAP

👥 Team size: 2–3 FTE

🔹 Responsibilities:

Develop and maintain backend APIs using C# and .NET

Build and maintain serverless solutions using Azure Functions

Work with Azure Cosmos DB as the primary NoSQL database

Develop and integrate cloud-based services

Contribute to event-driven architecture and messaging solutions

Collaborate with the team on API development and system integrations

🔹 Requirements:

Strong experience with C#

Solid experience with .NET Core / .NET 6/8

Hands-on experience with Azure Functions

Strong knowledge of Azure Cosmos DB

Good understanding of backend development and API architecture

English C1

🔹 Tech Stack:

C#, .NET 6/8, Azure Functions, Azure API Management, Azure Cosmos DB, Azure Storage, Azure Event Hub, Azure Service Bus, Azure Key Vault, Azure Active Directory, Azure Data Factory.

Additional technologies in the project ecosystem: Node.js, Express.js, TypeScript, React.js, Next.js, Redux, JWT, OIDC, Contentful.

Niko Technologies is an EU-licensed FinTech and Web3 product company. We develop specialized payment processing tools, digital card issuing, and crypto-fiat gateways for European businesses and individuals.

Flagship products: securepaycard.com, elegro.eu.

We are looking for a Middle / Senior Node.js Developer to expand our backend team and work on high-load, compliant transaction processing systems.

Tech Stack:

Node.js, TypeScript, NestJS, PostgreSQL, TypeORM / Prisma, Redis, Docker, CQRS / Event-Driven Architecture, RabbitMQ, Go (microservices), Jest.

What you will do:

• Architect, build, and optimize backend microservices handling financial transactions.
• Design clean, modular, and type-safe code applying SOLID and Clean Architecture principles.
• Scale data layer: query optimization, indexing, caching, and connection pooling.
• Implement fault-tolerant integrations with banking APIs and payment gateways.
• Cover critical logic with automated tests and participate in code reviews.

Requirements:

• 3+ years (for Middle) / 5+ years (for Senior) of production experience with Node.js and TypeScript.
• Solid hands-on experience with NestJS (or modern structured Express).
• Strong knowledge of PostgreSQL (query execution plans, indexing strategies, transactions).
• Practical experience with Redis (caching, locking, pub/sub) and Docker.
• Understanding of microservices design patterns, RESTful APIs, and asynchronous message processing.
• Good grasp of automated testing (Jest, integration tests).
• English: Intermediate (B1+) or higher.

Nice to have:

• Experience with message brokers (RabbitMQ or Kafka).
• Hands-on experience or interest in writing services in Go (Golang).
• Domain knowledge in FinTech, Payment Processing, PCI DSS, or Blockchain / Web3.
• Experience with performance profiling, memory leak tracking, and distributed tracing.

What we offer:

• Fully remote work with flexible hours (no micromanagement).
• Direct impact on licensed EU FinTech products with real payment volume.
• 100% company-funded professional courses, certifications, and conferences.
• Transparent communication, fast feedback, and healthy engineering culture.

Hiring Process:

1. Intro call with Recruiter (30 mins).
2. Technical Interview with Tech Lead (60 mins, no live-coding trivia — real architecture and code discussion).
3. Final chat & Offer.

Ready to join? Click "Open contacts" / "Відкрити контакти" to start a chat, or feel free to reach out with any questions directly!

We are seeking a highly skilled Regular Web Graphics Developer to join our team in the oil and gas industry. The ideal candidate will have extensive experience in developing advanced web-based visualizations and a deep understanding of industry standards. This role requires proficiency in WebGL and Three.js, along with a strong grasp of the graphics rendering pipeline. Experience with Unity or VR is a plus. Additionally, the candidate should possess general cloud development skills and backend expertise, including microservices architecture and experience with AWS and Azure.

Responsibilities

Design, develop, and maintain interactive web-based visualization tools for oil and gas data.

Implement advanced graphics rendering techniques using Angular, TypeScript, Three.js

Collaborate with geologists, engineers, and other stakeholders to understand visualization requirements and deliver effective solutions.

Ensure visualizations are optimized for performance and scalability.

Stay up-to-date with industry standards and best practices in web visualization and graphics rendering.

Integrate visualization tools with existing data management systems and workflows.

Develop and maintain backend services using microservices architecture.

Utilize cloud platforms such as AWS and Azure for deployment and management of visualization tools.

Provide technical guidance and mentorship to junior developers.

Skills

Must have

3+ years in Graphics development, with a strong emphasis on web-based Visualization applications and tools.

Bachelor's or Master's degree in Computer Science, Engineering, or a related field.

Strong proficiency in Angular, TypeScript and WebGL, Three.js

In-depth knowledge of the graphics rendering pipeline.

Experience with backend development and microservices architecture.

Proficiency in cloud platforms such as AWS or Azure.

Excellent problem-solving skills and attention to detail.

Strong communication and collaboration skills.

Ability to work independently and as part of a team.

Nice to have

Proven experience in web-based visualization development, particularly in the oil and gas industry.

Familiarity with AI

Project Description:

We are DXC Luxoft Financial Services, an award-winning provider of technology solutions dedicated to the Financial Services sector.

We are establishing a high-impact engineering squad in Bucharest to deliver a next-generation Financial Markets Clearing Platform for FX Swaps, a critical component in the global clearing ecosystem.

A key innovation area in this program is the adoption of AI-driven tooling to modernize and extend an existing service that currently processes CSV-based trade data. The goal is to intelligently transform and enrich trade data into compliant FPML (Financial products Markup Language) formats, supporting new and evolving product types with minimal manual intervention.

This initiative operates within a highly regulated, low-latency environment, with strict requirements around resilience, performance, and availability, while also preparing the platform for future cloud migration within the next 12–18 months.

You will work in an Agile Scrum environment, contributing across the full SDLC—from architecture and design to implementation, testing, and production rollout—while aligning with client engineering standards.

Team Overview
We are building a dedicated squad in Bucharest (Java Developers + QA Automation Engineers) working closely with global teams. The team operates in 2-week sprint cycles, following Agile ceremonies (stand-ups, retrospectives, backlog refinement).
The team will be responsible for end-to-end delivery of the FX Swaps product, including design, development, testing, production deployment, and post-go-live support.

Responsibilities:

Engineering & Delivery

- Design and deliver FX Swaps clearing microservices using Java 25 & Spring Boot 4
- Build low-latency, high-throughput systems for real-time trade processing
- Own full SDLC: design, development, testing, deployment, and production support
- Ensure compliance with performance, resilience, and availability standards

AI & Data Transformation

- Enhance and extend services converting CSV data into FPML format
- Implement AI-driven transformation and mapping logic for new product types
- Improve data quality, validation, and schema evolution capabilities
- Collaborate on AI-assisted data pipelines and transformation strategies

Architecture & Integration

- Design stateless, distributed microservices architectures
- Integrate with external FX trading venues and enterprise systems
- Apply caching strategies (Hazelcast or similar) for performance optimization

DevOps & Collaboration

- Contribute to CI/CD pipelines and automated releases
- Work in Agile Scrum teams and collaborate with global stakeholders

Mandatory Skills Description:

Core Technical Skills

- Strong experience in Java (11–25) and Spring Boot microservices
- Solid knowledge of Oracle DB (19c) and SQL optimization
- Experience working in Linux/Unix environments
- Hands-on experience with CI/CD tools (Jenkins, GitLab, Ansible)

Architecture & Systems

- Strong understanding of microservices and stateless design principles
- Experience building low-latency, high-availability distributed systems
- Knowledge of integration patterns in enterprise systems
- Experience with caching solutions (Hazelcast or similar)

Data & AI Awareness

- Experience working with data transformation (CSV, XML, FPML or similar)
- Understanding or exposure to AI/ML-driven data processing or automation

Delivery & Collaboration

- Proven experience as a Senior Java Developer (3+ years in similar role)
- Strong ownership, problem-solving mindset, and Agile/Scrum experience

Nice-to-Have Skills Description:

Nice-to-Have
• Capital Markets / FX products knowledge and cloud exposure (AWS or similar)

What should you know about SKELAR? It's a venture builder — in other words, a company that builds companies. Together with founders, we create consumer businesses that become leaders in global markets across EdTech, Mental Health, Petcare, FashionTech, and beyond.

Our teams build tech products that win recognition from Product Hunt and The Webby Awards, earn thousands of glowing Trustpilot reviews, and reach over 10 million users worldwide. That kind of impact doesn't happen by accident — it starts with exceptional people, and our people are our top priority.

We've built an environment where expertise meets opportunity, and where there's no ceiling on what you can achieve. Now we're looking for the kind of people who don't just want a job — they want a challenge.

We’re looking for a BackEnd Engineer (MarTech) for our partner company, Duomo.

Duomo is an app rooted in Christian values, helping people turn Scripture into daily habits and inner peace. We’re building a leading Christian-tech product for people seeking spiritual renewal.

You will be responsible for:
 

• Driving MarTech Automation: Designing, developing, and scaling backend services to automate marketing technology processes and integration workflows.
• Streamlining Creative Processes: Building robust tools and systems that automate the asset lifecycle and streamline creative operations for the team.
• Enhancing System Observability: Implementing comprehensive tracking, metrics, logs, and tracing (Observability) to ensure high system visibility and performance monitoring.
• Strengthening Infrastructure Reliability: Expanding test coverage (unit, integration, end-to-end) and setting up automated testing pipelines to ensure high code quality and fault tolerance.
• Architecting Scalable Solutions: Participating in system architecture design, code reviews, and optimizing backend performance to support business growth.

What you need to succeed in this role:

• 2+ years of experience with Node.js + TypeScript & NestJS.
• PostgreSQL + any typed ORM (Drizzle, Prisma, or TypeORM).
• Redis & Message Queues (BullMQ, RabbitMQ, or SQS) — hands-on experience with idempotency, retries, and distributed locks.
• Third-party REST API integrations — handling rate limits, pagination, and partial failures.

• Docker, CI/CD, and unit testing with Jest

   

  Nice-to-Have Requirements

• Experience with Facebook Marketing API, Google Ads API, or other ad platforms (TikTok, Applovin)
• Cloud & Infra: AWS (ECS, ECR, S3, Lambda) and GitHub Actions
• Observability: Prometheus, Grafana, and structured logging
• Integrations with Airtable API and Google Sheets API
• Practical experience with LLM APIs (Claude, Gemini) — structured output and prompt versioning

Why Duomo:

— You’ll work on a product with a clear mission and real values.
— You’ll help us transition from a content-rich app into a truly connected spiritual platform.
— You’ll be early enough to influence how product is done at Duomo long-term.

What we offer:

— Competitive salary;
— Significant impact on a rapidly growing business and contribution to how it shapes up;
— Ample career opportunities for ambitious growth and development;
— A possibility to attend internal, external courses, seminars and the access to a corporate library;
— Comfortable working environment. We provide all necessary work equipment for your role and serve complimentary breakfasts, lunches, and snacks in the office;
— 20 days of paid vacation, medical insurance and a variety of sports activities available for employees inside and outside the office.

At SKELAR, we've built an environment where people can grow, build, and do the most meaningful work of their careers:

• SKELAR Platform. The operational backbone of our venture builder. It exists to help founders move faster and easier — so business teams can stay laser-focused on the product while 10+ specialized Platform takes care of everything else: Legal, Finance, HR, Admin, Talent Acquisition, Employer Branding, IT, and more.
• Networking and knowledge-sharing as a way of life. Our people include co-founders who've launched multiple businesses and some of the sharpest specialists in the industry. Whatever expertise you need, it's never far away.
• Learning programs you won't find anywhere else. We've developed our own educational tracks for teammates to choose from — a two-month school for first-time managers, intensive AI workshops, and professional clubs for engineers, product managers, and more.
• Meaningful impact in Ukraine. The SKELAR Foundation was created by our own people, and every employee plays a part in bringing important social initiatives to life. We founded Europe's first accelerator for veterans and are working to build lasting support structures for veterans at a national scale.
• Spaces designed to inspire. Our offices are places people actually want to be — with an in-house gym, a climbing wall, Bali-inspired green spaces, and libraries. Every detail, from service and security to comfort and design, is built to match the pace of our growing teams.
• Everyday comfort built in. Meals, gym access in Kyiv or a partial fitness stipend in Warsaw, health insurance, paid business travel where the role requires it, and corporate partner discounts.

We'd love to tell you more in person.

Join us at SKELAR and help build the next big everything!

About the project

Our client is a fintech company building a new digital banking and payments product from scratch. You will join the team building its card issuing platform (issuer processing): real-time card authorisation, clearing and settlement, and integrations with the card scheme, a banking partner and payment providers.

The product is at an early stage: architecture, team and roadmap are being shaped now, and the scope will be refined together with the team. You will join a mixed team of client and NerdySoft engineers. AI-assisted development is part of everyday engineering.

What you will do

• Design, build and ship Java services of a new card processing platform
• Implement card transaction flows: authorisation, reversals, refunds, clearing and settlement - correct and idempotent at money level
• Build reliable integrations with the card scheme, banking partner and payment providers - traceable and easy to reconcile
• Own the technical design of features and components, and contribute to architecture decisions together with the Tech Lead
• Keep the bar for quality: code reviews, testing standards, performance, reliability and security (PCI DSS)
• Work with AI coding assistants and AI agents in daily development: delegate tasks to agents, review the code they produce and keep it to the team's standards for review and testing
• Support features in production: monitoring, incident analysis, fixes
• Mentor middle engineers; clarify requirements and discuss technical solutions directly with client stakeholders

What you bring

• 5+ years of commercial backend development with Java (17+) and Spring Boot
• Commercial experience in card payments, issuing side preferred: card issuing or issuer processing, acquiring, payment gateways / PSPs or card scheme integrations
• Production experience with high-load, transactional, event-driven systems (Kafka, RabbitMQ, AWS SNS/SQS or similar)
• Solid knowledge of concurrency and transactions: ACID, isolation levels, optimistic and pessimistic locking, idempotency
• Strong PostgreSQL (or other relational DB) skills: schema design, query optimisation, JPA / Hibernate
• Integrations with external providers: retries, timeouts, reconciliation, consistent error handling
• Strong testing culture: unit, integration and contract tests (JUnit, Mockito, Testcontainers)
• Docker, CI/CD and hands-on AWS (or another major cloud)
• Daily use of AI coding assistants and agents (Claude Code, Cursor, GitHub Copilot or similar): you can show how they speed you up and how you check their output
• English B2+ (Upper-Intermediate or higher): you will discuss technical solutions directly with the client

Nice to have

• Issuer processing: ISO 8583, authorisation, clearing and settlement files, chargebacks
• Visa or Mastercard integrations and scheme certification
• Tokenisation for digital wallets, 3DS
• PCI DSS in practice; HSM and key management
• Ledger systems and double-entry accounting
• Kotlin or Scala; DDD, Clean or Hexagonal architecture; Kubernetes, Terraform

What we offer

• Comfortable workplace and modern office facilities
• Flexible working hours with no overtime and the ability to work remotely
• 50% compensation for certifications, conferences, training
• 50% compensation for English courses
• 18 working days of paid annual leave
• Paid sick leave
• Medical insurance and sports compensation

We're looking for a Senior Quant Developer for a specialized fintech company that builds front-office software for commodities trade risk assessment. The company was founded in 2015 by alumni of London investment banks and hedge funds. The product is used by traders every day. You would join a developer-driven team that prefers writing new code to maintaining legacy systems. You'd design, build and test core front-office components, data pipelines and market data ingestion tools. This role suits an academically strong engineer who enjoys hard technical problems, and who likes working at a whiteboard with colleagues in the office.

Details

• Location: Warsaw (Powiśle), hybrid, with most days in the office
• Employment: Full-time
• Level: Mid-Senior

What you'll do

• Design and develop front-office components used by traders daily
• Build and maintain data pipelines and ETL processes
• Own market data ingestion: streaming, time-series and high-frequency trade data
• Test your own work and contribute to the technical decisions of a small, specialized team

Requirements

• 5+ years of software engineering experience
• Expert-level Python
• Proven experience with streaming technologies such as Kafka and Redis
• Degree in Computer Science, Mathematics, Physics or a related field
• Strong knowledge of data structures and algorithms
• Ability to work from the Warsaw office most days (fully remote is not possible)

Tech stack

Python, SQL, NoSQL, Kafka, Redis, ETL, Time Series, AWS / Azure

Nice to have

• A PhD
• Experience in financial markets or commodities trade risk
• Cloud experience (AWS or Azure)
• Olympiad achievements (Informatics or Mathematics)
• A degree from the University of Warsaw (JSIM, CS, Math, Physics) or a background at Staszic / Matex

Interview process

1. Informal introduction: a casual chat with the founders
2. Technical assessment: a practical task to see how you code and solve problems
3. Team meeting: meet the people you'd be working with

Insiders is a fast-growing IT company which employs about 200 people. Our company focused on providing innovative digital services and cutting-edge technologies to solve complex business challenges.

We are located in Lviv and currently work in an office format. 

What we expect from the candidate:

- Experience in development using the Python programming language is required.

- Strong knowledge of frameworks such as Django, Django REST Framework (DRF), and FastAPI.

- Experience with database migrations using Alembic and Django ORM.

- Understanding of the fundamental principles of object-oriented programming is essential.

- Proficiency in working with databases such as MySQL and PostgreSQL is important.

- Experience with version control systems like Git is mandatory.

- The candidate must demonstrate seriousness and the ability to collaborate effectively both in a team and independently.

what we offer:

- free study in our Corporate English Academy

- growth and development opportunities for young developers even if you have no commercial experience

- regular salary review (after the completion of each contract)

- provision of Apple equipment

- comfortable office with all amenities not far from the center (uninterrupted internet, generator, tea and coffee, pastries).

- timely payment of salaries.

- corporate events, teambuildings, etc.

- working on projects side by side with Senior developers, which will give you the opportunity to learn and develop.

Company Overview

We're a pioneering company transforming business needs through innovative solutions for our exclusive client. Our mission is to deliver informative SaaS products that align with modern design solutions and cutting-edge technologies.

Role Overview

We’re on the hunt for an ambitious and curious Trainee Node.js (Next.js) Developer who is eager to kickstart their career in web development and passionate about exploring modern technologies and AI-powered development tools.

In this role, you won’t just learn how to build web applications; you’ll gain hands-on experience working with Node.js, Next.js, and modern JavaScript technologies while discovering how AI tools can make development workflows smarter and more efficient.

Join our vibrant office space, where you’ll work alongside passionate developers and experienced mentors. If you’re excited about coding, solving technical challenges, and building modern web applications, we’d love to meet you!

🎯 Mission

Master the fundamentals of web development using Node.js and Next.js, learn to build functional and scalable web applications, and actively explore AI tools to improve your coding workflow, problem-solving skills, and development efficiency.

✅ Key Responsibilities

• Assist in developing and maintaining web applications using Node.js and Next.js
• Build basic application features, UI components, and server-side functionality based on predefined requirements
• Work with JavaScript / TypeScript to write clean, readable, and maintainable code
• Learn to develop and maintain API endpoints and integrate third-party services
• Work with databases to store, retrieve, and manage application data
• Use Claude, ChatGPT, and other AI tools to explore technical solutions, generate code suggestions, debug issues, and optimize development tasks
• Collaborate with experienced developers to understand coding standards and best practices
• Participate in code reviews, team discussions, and brainstorming sessions

• Fix basic bugs and gradually take ownership of small development tasks

   

🛠 Requirements

• Basic knowledge of JavaScript and understanding of fundamental programming concepts
• Basic understanding of Node.js and its core concepts
• Familiarity with React: components, props, state, and hooks
• Basic understanding of Next.js or strong motivation to learn the framework
• Understanding of asynchronous JavaScript (Promises, async/await)
• Basic knowledge of HTML, CSS, and web development principles
• Understanding of REST API concepts and how client-server communication works
• Basic knowledge of Git and version control fundamentals
• AI curiosity – willingness to experiment with Claude, ChatGPT, and other AI tools to solve development tasks and improve productivity
• Strong logical thinking and problem-solving skills
• Eagerness to learn quickly and handle constructive feedback professionally

• English level: Upper-Intermediate or higher – comfortable reading technical documentation, using English-language AI tools, and communicating with the team

   

🌟 Nice-to-Haves

• Educational, personal, or pet projects built with Node.js, React, or Next.js
• Basic understanding of TypeScript
• Familiarity with databases such as PostgreSQL or MongoDB
• Basic knowledge of SQL
• Understanding of authentication and authorization concepts
• Experience working with REST APIs
• Familiarity with Next.js features such as App Router, Server Components, and API Routes
• Basic understanding of deployment processes and hosting platforms
• Experience with AI-powered development tools and Prompt Engineering

• A GitHub profile with personal or educational projects

   

Collaboration Format

• Full-time (on-site)
• Work closely with experienced Node.js / Next.js developers who will provide guidance and mentorship
• Collaborate with the development team on real commercial projects

• Clear growth path to transition into a Junior Node.js (Next.js) Developer role

   

What We Offer

• Dedicated mentorship and hands-on training with real commercial projects
• An opportunity to develop your skills in modern backend and full-stack technologies
• Practical experience with Node.js, Next.js, and the latest AI-powered development tools
• A supportive environment where asking questions, experimenting, and learning are encouraged
• Regular feedback and guidance from experienced developers

• Competitive starting compensation package for entry-level positions

   

Even if your experience doesn’t perfectly align with all the requirements, we encourage you to apply. We’re looking for someone with a strong learning mindset, genuine curiosity, and the motivation to grow into a great developer!

About Us

Smart Capital Center is an end-to-end, AI-powered platform for Commercial Real Estate (CRE) investment and financial management. We power real-time underwriting, asset management, and portfolio analytics through a combination of live data, workflow automation, and AI-driven insights.

Operating at the intersection of Generative AI, finance, and real estate, we are building systems that digitize and simplify complex financial workflows.

Our clients include leading institutions such as JLL, Pacific Life Insurance Company, and KeyBank. We are a lean, high-performance team building category-defining technology in a $17 trillion industry.

To learn more about our platform and vision, please visit our website.

The Role

We are looking for a Backend Software Engineer with strong experience in building scalable systems and a deep interest in AI-powered applications.

This is a high-impact, hands-on role where you will design and build backend services, integrate AI capabilities, and develop intelligent, agent-driven workflows used in real-world production environments.

You will work closely with product, AI, and engineering teams to deliver reliable, high-performance systems and automation features.

What You Will Do

Backend Development

• Design, build, and maintain backend services using Java (Spring Boot) and Python
• Develop scalable APIs and microservices for data-intensive applications
• Optimize system performance, reliability, and scalability
• Design efficient data models and handle complex integrations

AI & Intelligent Systems

• Implement and integrate AI-powered features into core products
• Design and build agent-based workflows for automation and decision-making
• Apply prompt engineering techniques to improve LLM outputs and behavior
• Work with modern AI frameworks to productionize intelligent systems

Cloud & Infrastructure

• Develop and deploy backend systems on AWS (EC2, S3, RDS, Lambda, etc.)
• Build resilient, scalable cloud-native services
• Contribute to system monitoring, logging, and reliability

System Design & Engineering Excellence

• Contribute to architecture, service boundaries, and system design decisions
• Write clean, maintainable, and well-documented code
• Ensure security, performance, and operational stability
• Continuously improve engineering quality and development practices

Collaboration

• Work closely with frontend, product, and AI teams
• Contribute to end-to-end feature delivery
• Participate in Agile development processes

Requirements

• 5+ years of backend software development experience
• Strong experience building and scaling backend systems in production

Core Technical Skills

• Strong experience with Java and Spring Boot
• Solid experience with Python
• Strong knowledge of SQL and database design (PostgreSQL preferred)
• Experience building REST APIs, microservices, and distributed systems
• Hands-on experience with AWS (EC2, S3, RDS, Lambda, etc.)
• Proficiency with Git and modern development workflows

AI & Modern Development Experience

• Experience with prompt engineering for LLM-based systems
• Practical experience building AI agent workflows in production
• Familiarity with frameworks/tools such as:
  • LangGraph
  • LangChain
  • LangSmith
  • or similar ecosystems
• Experience using AI-assisted development tools, such as:
  • Claude Code
  • Codex
  • OpenCode
  • or similar

Nice to Have

• Experience with vector databases or semantic search (e.g., Milvus)
• Knowledge of RAG (Retrieval-Augmented Generation) architectures
• Experience with CI/CD pipelines and DevOps practices
• Familiarity with event-driven architecture

• Experience with data processing pipelines or document AI systems

   

Why Join Us

• Work on cutting-edge AI-powered systems in a $17T industry
• Build real-world applications using LLMs, agents, and automation
• High ownership and autonomy with meaningful technical impact
• Opportunity to influence system design and engineering direction
• Fast-moving, execution-focused team with minimal bureaucracy
• Competitive compensation and flexible work environment

If you design and simulate circuits in Qucs-S and can explain your reasoning as clearly as you build, this role puts that skill to work. You’ll join a remote AI training project for a global AI company, solving real circuit design and simulation tasks in Qucs-S and walking through your workflow step by step, so AI systems learn how electronics engineers actually work. Fully remote, flexible hours, paid by the hour.

Your responsibilities will include:

• Design and simulate electronic circuits using Qucs-S.
• Work with analog, digital, and mixed-signal circuits.
• Run circuit analysis, including AC, DC, and transient simulations.
• Troubleshoot circuit issues and improve circuit performance.
• Complete advanced Qucs-S tasks and explain your workflow step by step.

• Write clear instructions and detailed prompts for circuit simulation tasks.

   

What we expect from you:

• Strong professional, hands-on experience with Qucs-S.
• Hands-on experience with electronic circuit design and simulation.
• Good understanding of SPICE simulation, circuit analysis, and electronic components.
• Experience troubleshooting circuits and analyzing simulation results.
• Access to Qucs-S and comfort recording your screen while you work.
• English at B2 level or higher.

• Ability to explain technical workflows clearly.

   

Nice to Have:

• A master’s degree or PhD in Electrical or Electronics Engineering.
• Experience with other circuit simulation or EDA tools.
• Professional experience in electronics or hardware engineering.

• Previous AI data experience (data annotation, RLHF, or AI model evaluation) is a plus, but not required

   

What we offer:

• Hourly pay for real, hands-on engineering work.
• Fully remote work with a flexible schedule: you choose when you work.
• A chance to shape how next-generation AI understands electronics engineering.
• A short, simple selection process with a fast start.

About the project

Our client is a fintech company building a new digital banking and payments product from scratch. You will lead the team building its card issuing platform (issuer processing): real-time card authorisation, clearing and settlement, and integrations with the card scheme, a banking partner and payment providers.

The product is at an early stage: architecture, team and roadmap are being shaped now, and the scope will be refined together with the team. You will join a mixed team of client and NerdySoft engineers and work closely with the client's technical leadership. AI-assisted development is part of everyday engineering.

What you will do

• Lead and mentor a team of 3–6 engineers while staying hands-on: at least half of your time is production code
• Shape the architecture of a new event-driven card processing platform and own technical decisions in your area
• Lead the implementation of card transaction flows: authorisation, reversals, refunds, clearing and settlement - correct and idempotent at money level
• Own code quality: code reviews, testing standards, secure coding practices
• Build reliable integrations with the card scheme, banking partner and payment providers - idempotent, traceable and easy to reconcile
• Make sure the solution meets security and regulatory requirements, including PCI DSS
• Create and onboard AI powered SDLC process and help the team adopt them with clear rules for review and testing
• Deliver features end to end, from technical design to production support
• Break down scope, estimate and plan delivery together with Product Manager
• Be the main technical point of contact for client stakeholders

What you bring

• 7+ years of commercial backend development with Java (17+) and Spring Boot
• 2+ years as a Tech Lead or Team Lead of 3+ engineers, while still writing code
• Card payments experience is mandatory, issuing side preferred: card issuing or issuer processing, acquiring, payment gateways / PSPs or card scheme integrations
• Production experience with asynchronous, event-driven systems (Kafka, RabbitMQ, AWS SNS/SQS or similar)
• Solid knowledge of concurrency and transactions: ACID, isolation levels, optimistic and pessimistic locking
• Strong relational database skills (PostgreSQL preferred), JPA / Hibernate
• Experience integrating external APIs and providers: retries, timeouts, idempotency, consistent error handling across layers
• Designing secure public APIs for external integrations: authentication, authorization, platform boundaries
• Architecture know-how: DDD, Clean or Hexagonal architecture; you can design a system from scratch and defend the decisions
• Hands-on AWS (or another major cloud), Docker and CI/CD, including API versioning and database migrations
• Strong testing culture: unit, integration and contract tests (JUnit, Mockito, Testcontainers)
• Daily use of AI coding assistants (Claude Code, Cursor, GitHub Copilot or similar): you can show how they speed you up and how you check their output
• English B2+ (Upper-Intermediate or higher): you will lead technical discussions with the client

Nice to have

• Issuer processing (top priority): ISO 8583, authorisation, clearing and settlement, reversals, chargebacks
• Visa or Mastercard integrations and scheme certification
• PCI DSS in practice; HSM, key management, tokenisation for digital wallets
• Ledger systems and double-entry accounting
• Bank transfer and direct debit integrations (SEPA or other domestic payment rails)
• Kotlin or Scala; Kubernetes, Terraform; schema evolution with Avro or Protobuf
• Work in a regulated financial environment
• Threat modelling

What we offer

• Comfortable workplace and modern office facilities
• Flexible working hours with no overtime and the ability to work remotely
• 50% compensation for certifications, conferences, training
• 50% compensation for English courses
• 18 working days of paid annual leave
• Paid sick leave
• Medical insurance and sports compensation

Blackthorn Vision is looking for a Middle/Middle Strong .NET Engineer. Our client, established in 2011 and based in Colorado, is a leading player in the U.S. application management market. We’ve had a successful partnership with this client and are seeking candidates who are eager to take ownership and improve a product already trusted by over 6,000 enterprises.

Requirements:

• 4+ years of commercial experience working on the backend as a .NET developer.
• Cloud systems development experience.
• Understanding of data access technologies, including Entity Framework and MongoDB.
• Experience with both SQL and NoSQL databases.
• Experience with microservice-oriented architecture, parallel, and asynchronous programming design patterns.
• Experience with Kubernetes, Docker, and RabbitMQ.
• Proven experience with Azure technologies: Azure Entra ID, Azure Storage accounts, Azure Service Bus, Azure Container Registry.
• Knowledge of design and architectural patterns.
• English level: Upper-Intermediate.

Responsibilities:

• Develop and maintain high-quality software solutions using .NET 8.0.
• Take full ownership of delivering new features to end users, including designing architecture, implementing, testing, and onboarding the customer support team with new functionality.
• Collaborate with product owners, the support team, and end users to understand project requirements and deliver solutions.
• Participate in code reviews to enhance overall code quality.
• Ensure applications are high-performing, responsive, and of excellent quality.
• Troubleshoot and resolve technical issues and defects promptly.
• Create code documentation, technical specifications, and architecture diagrams for new features.
• Follow agile methodologies and participate in regular sprint planning and review meetings.

You are compatible with us if you:

• Have a strong product mindset.
• Have a proactive approach to taking ownership of decisions/features.
• Possess a strong, curiosity-driven mindset.
• Are comfortable with challenges.
• Have the ability to collaborate and build relationships with diverse personalities.
• Demonstrate customer-focused decision-making.
• Exhibit clear and timely communication.
• Are open to giving and receiving constructive feedback.
• Value the quality of your code.
• Are able to solve the required technical tasks and communicate throughout the process (for example, asking clarifying questions promptly).

About Us

We are a deep-tech company building state-of-the-art LLM-based assistants augmented with knowledge graphs. We are seeking a Senior Backend Python Engineer (7+ years of experience) to design and scale the backend infrastructure powering our AI platform.
 

Key Responsibilities

• Architect and implement scalable backend services and multi-tenant SaaS systems.
• Design and operate high-throughput data pipelines (both batch and streaming).
• Build APIs and services integrating LLM inference, retrieval systems, and knowledge graphs.
• Productionize research-grade AI systems into reliable, production-ready distributed systems.
   

Core Requirements (Must Have)

• Experience: 7+ years of hands-on backend engineering experience.
• Architecture & Data: Strong background in building high-throughput data pipelines and multi-tenant SaaS architectures.
• Programming: Deep proficiency in Python.
• Distributed Systems: Strong understanding of distributed systems and cloud-native environments.
• Kubernetes: Hands-on experience in the architecture, development, and deployment of Kubernetes-based systems.
   

Nice to Have

• Languages: Experience with Go and/or Scala.
• AI/LLM Ecosystem: Practical experience with LLM systems (RAG, model serving, evaluation).
• Graph & Vector Databases: Experience working with knowledge graphs, vector databases (e.g., Neo4j), or hybrid retrieval architectures.

Why Join Us? 

    🌍 Remote-first & flexible work

• Fully remote working model.
• Access to an office if there is one available in your location.
• Monday–Friday, 40-hour working week.

• Flexible working hours: schedule options between 08:00 and 19:00, including a 1-hour lunch break (the only requirement is a minimum of 5 hours of overlap with the team)

  🏖️ Vacation & sick leave

• 20 paid working days of vacation during the first year.
• 10 paid sick days per year (for childcare would also be covered), compensated at 100% of salary.

• Public holidays are days off by default.

  ❤️ Health & family benefits

• Medical insurance or medical insurance compensation.
• Company gifts for:
  • Birthday
  • Wedding
  • Birth of a child
• Paid lunches at the office.
• Family days etc.
• 📑 FOP / Individual Entrepreneur Support if needed
  🔄 Paid Bench period between projects
  🤝 No time-tracking software — transparent and trust-based time reporting.
  🎁 Referral Program

We’re developing a business spending and payments platform within a startup studio. We’re looking for a hands-on Tech Lead to guide its technical transformation and grow into full engineering ownership.

You’ll combine active development with architecture decisions, production reliability, and team leadership, working closely with the product and studio teams.

What we’re looking for

• Strong backend experience with PHP, Laravel/Lumen, MySQL, and Redis.
• Working knowledge of JavaScript and basic familiarity with Vue.js and React.
• Experience with Docker and practical DevOps: configuring and maintaining Linux servers, deployment pipelines, monitoring, and backups.
• Understanding of the card transaction lifecycle: authorisation, capture, clearing, settlement, reversals, refunds, and chargebacks—including when funds are reserved, moved, or released.
• Understanding of crypto fundamentals: networks, coins, tokens, and which assets pay transaction fees on each network.
• Experience building reliable financial systems: accurate balances, reconciliation, audit trails, secure APIs, and safe handling of retries and duplicate events.
• Ability to improve an existing codebase while keeping the product stable and delivering new functionality.

How you work

You take responsibility from technical decisions through delivery and production support. You communicate clearly, explain trade-offs to non-technical colleagues, flag risks early, and follow through on commitments. You can prioritise independently, mentor developers, and maintain quality through code reviews and meaningful testing.

An opportunity to shape the architecture, strengthen the team, and take long-term ownership