Junior AI-Assisted.NET Developer

About the Position

We are seeking a Junior AI-Assisted .NET Developer to join Group107 for a Summa. You will work inside the AI Unit on a mature, production .NET codebase powering a multi-tenant SaaS platform for the accounting and tax industry, used daily by professional finance teams. The platform automates corporate and personal tax forms, statutory electronic filings, audit workflows, client management, and the generation of Excel, PDF, and Word deliverables for the Israeli market. You will work directly alongside a senior developer and progressively take ownership of well-scoped backend slices: bug fixes, data scripts, tax-form logic, report generation, and API endpoints.

To be explicit: you will use AI to build accounting and tax software - you will not be building AI models or LLM products. This is a real production system handling sensitive financial data, so reviewing, testing, and verifying AI output matters as much as generating it.

Responsibilities

• Ship backend features in C# /.NET 8: ASP.NET Core controllers, MediatR CQRS commands and queries, FluentValidation, services and repositories, and EF Core migrations.
• Drive Claude Code as your main tool: plan before editing, write precise prompts, keep diffs small and reviewable, enforce the documented repository conventions, and reject output that is wrong or out of scope.
• Implement tax and accounting logic: annual regulatory specification updates, tax-form calculation fields, fixed-width statutory filing files, and the data model behind them (domain guidance is provided).
• Generate document outputs - Excel, fillable PDFs, Word-to-PDF, HTML-to-PDF - and translate written specifications (form specs, client change requests, support tickets) into working code.
• Work in SQL Server: queries, stored procedures, diagnostics, and carefully scoped data-fix scripts across a multi-tenant database estate.
• Write unit tests with MSTest, Moq, and MockQueryable; write a failing test first for bug fixes and keep coverage from sliding.
• Pick up smaller full-stack frontend tasks in Angular 21 (signals, reactive forms, AG Grid, EN/HE translations) - roughly 10% of the work; this is a backend role.
• Build internal tooling and automation - Claude Code skills, subagents, custom commands and hooks, plus one-off Python and SQL scripts - and document your work in Jira tickets, PR descriptions, and knowledge-base notes.

Requirements

• 1+ year of hands-on software development
• Good knowledge of C# and .NET (ASP.NET Core) - able to read, navigate, and extend a large existing codebase.
• SQL fundamentals: joins, aggregation, indexes, transactions.
• Demonstrable daily proficiency with Claude Code (or Cursor / GitHub Copilot): context management, planning before editing, scoping changes, iterating on failures.
• Ability to read, debug, and refactor AI-generated code critically. Blind trust in AI output is a disqualifier.
• LLM fundamentals: prompting, context windows, token budgets, tool use, and typical failure modes (hallucinated APIs, silent scope creep).
• Git proficiency: feature branches, rebase, conflict resolution, clean conventional commit messages.
• English - Upper-Intermediate (B2)+.
• Precision with detail: much of the output is a document or a number a professional accountant will read - a misaligned column, wrong font, or value off by one is a defect, not a cosmetic issue.
• Critical thinking: AI writes code; you decide whether it is correct, safe, and in the right place, and know when to throw an answer away.
• Speed of learning: AI tooling changes weekly - you track it, try it, and adopt what works without being told.
• Bias toward shipping: small, reviewable pull requests (target under 400 changed lines), merged often, and verified in the running application.
• Autonomy: you get direction, not hand-holding - investigate first, ask sharp questions when genuinely blocked, then deliver end to end.
• Respect for production: destructive commands, unscoped updates, and leaked secrets are unacceptable. Measure twice, run once.

Nice to Have

• EF Core migrations, MediatR / CQRS, and multi-tenant architecture.
• TypeScript and modern Angular (17+ signals) or another SPA framework.
• Document automation: OpenXML, iText / PDFsharp, LibreOffice headless conversion.
• Docker, CI/CD pipelines (GitHub Actions or equivalent), and AWS or Azure basics.
• Advanced Claude Code usage: custom skills, subagents, hooks, MCP servers, headless / scripted runs.
• OCR / document-AI services (Azure Document Intelligence, Google Document AI, ABBYY) or LLM API integration into a backend service.
• Hebrew reading ability and/or RTL interface experience - a significant advantage (not a hard requirement; the team works with translation support).
• Any exposure to accounting, tax, or fintech domains.

We Offer

• 20 vacation days (workdays)
• 7 sick days
• Personalized career growth
• Internal English classes
• Education reimbursement
• Corporate events and team buildings
• Equipment provided

About the Company

We are seeking a Junior AI-Assisted .NET Developer to join our team and work on a mature.NET codebase for a SaaS platform in the accounting and tax industry. The platform automates corporate and personal tax forms, statutory electronic filings, audit workflows, client management, and the generation of Excel, PDF, and Word deliverables for the Israeli market.

Company Culture:

• Denys Bondar, PHP Developer: "I like the company that we all work as a united and well-coordinated team. The company provides great opportunities for development and career."
• Dmytro Omelian, Motion Designer: "I like the fact that I have the freedom to be creative and really cool projects."
• Anastasia Makosiy, Scrum Master: "In 2020, Group 107 came into my life and became my place of strength and development."
• Samuel Aina, SMS/Email Campaigner: "It is the best position ever!"
• Nazar Rudyi, Front-End Developer: "The company has very interesting and cool projects, mega-positive people."
• Iurii Masliuk, Graphic Designer: "I like that company cares about me as a person and about my personal growth. I like being appreciated and listened to."
• Mykhailo Chonka, Senior Motion Designer: "The company combines dynamic business approach with top-notch technologies and very strong people-oriented values."
• Iryna Myasnikova, Head of PMO: "It is my best decision ever!"
• Anna Labish, Recruiter: "The feeling of support and friendship remains the same as in a small team."
• Oleg Bortnyk, UI/UX Designer: "The family atmosphere, interesting projects, flexible management, and the opportunity to develop my professional skills every day."
• Yuliia Bedzai, Graphic Designer: "From the beginning, I felt like I’m in a big family where everybody supports each other and ready to help at any time. Group 107 gives great opportunities to develop your skills."

Apply now and join our team!