Junior AI-Assisted .NET Developer

Project overview

We are looking for 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.

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.

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.

We offer

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