# How I Shipped 15 Green MRs to GitLab in One Day: Inside Our Modern Contributor Tech Stack > Source: > Published: 2026-10-25 17:07:34+00:00 Contributing to one of the largest open-source platforms in the world is usually described as slow, deliberate, and fraught with complex CI pipelines. Today, across three distinct upstream GitLab repositories, our engineering pipeline achieved a landmark milestone: **15 out of 15 Merge Requests 100% Green in CI, 100% assigned to maintainers and domain reviewers**, and officially crossing **4,197 live contributor points** on track to the prestigious **Level 4 Contributor milestone (7,500 pts)**. How do you tackle 15 upstream issues across **Ruby**, **TypeScript**, and **Python** in a single sprint without breaking pipelines or getting bogged down in review cycles? Here is an architectural breakdown of the **modern tech stack** we use every day to solve GitLab issues at enterprise velocity. GitLab is no longer just a monolithic Ruby on Rails application. Modern AI-assisted software delivery requires a distributed ecosystem: ``` ┌────────────────────────────────────────────────────────────────────────┐ │ Developer / Agentic Client │ │ (Claude Desktop, Cline, Cursor, Antigravity) │ └───────────────────────────────────┬────────────────────────────────────┘ │ Model Context Protocol (JSON-RPC) ▼ ┌────────────────────────────────────────────────────────────────────────┐ │ GitLab Core MCP Server (Ruby on Rails) │ │ lib/api/mcp/handlers & JSON-RPC Router │ │ │ │ • list_pipeline_schedules • create_merge_request_pipeline │ │ • list_work_items (filter) • save_work_item (description_edits) │ │ • list_user_events • get_pipeline (poll hints) │ └───────────────────┬────────────────────────────────┬───────────────────┘ │ │ ▼ ▼ ┌──────────────────────────────────────┐ ┌──────────────────────────────┐ │ GitLab LSP (TypeScript / Node.js) │ │ AI Gateway (Python / FastAPI│ │ editor-extensions/gitlab-lsp │ │ modelops/.../ai-assist │ │ │ │ │ │ • Virtual Workspace File Indexing │ │ • Agent Platform Guard │ │ • WebSocket Lifecycle & Leak Fix │ │ • Duo Workflow Service │ │ • Multibyte UTF-8 Chunk Decoder │ │ • APIStatusError Handling │ │ • CLI Slash Command Wake Queue │ │ • Tool Execution Loop │ └──────────────────────────────────────┘ └──────────────────────────────┘ ``` GitLab Core is pioneering native support for Anthropic's **Model Context Protocol (MCP)** directly within its Rails application (`lib/api/mcp/`). This allows AI agents to interface directly with GitLab issues, pipelines, notes, and work items via structured JSON-RPC. `rspec:predictive`) We implemented and polished **9 distinct MCP tool endpoints**: `list_pipeline_schedules``!264856`): Exposing CI schedule discovery to AI agents.` create_merge_request_pipeline``!264858`): Giving agents the ability to trigger targeted MR pipeline runs.`save_work_item` with `description_edits` & `expected_updated_at``!264862`): Adding optimistic locking and targeted string replacement diffs to prevent concurrent edit collisions.`list_work_items` with `parent_id` hierarchy filter`!264859`): Allowing recursive task tree traversal.` get_pipeline` with `poll_after_seconds` hint`!264863`): Teaching AI agents how long to sleep before polling pipeline status.`list_user_events``!264864`): Activity feed telemetry tool for AI agents.`!264852`): Transparently accepting `query` and `search_term`.`!264853`): Reporting unknown parameter names with suggestions.` save_note` updating`!264854`): Allowing AI agents to update existing issue notes. In GitLab Rails helpers, never declare unmemoized instance variables (`@variable`). RuboCop will flag this under `Gitlab/PredicateMemoization` or helper encapsulation rules. Clean encapsulation in service classes keeps CI 100% green on the first push! The `gitlab-lsp` powers language intelligence and Duo AI features inside VS Code, WebIDE, and JetBrains. `ws`)`!4537`, `#3364`)` NodeJS.Timeout`) was not cleared. Over time, reconnect attempts created zombie timers that leaked memory. ``` // Explicit cleanup on upgrade rejection this.ws.on('unexpected-response', (_req, res) => { this.clearHeartbeat(); this.emit('error', new UpgradeError(res.statusCode)); }); ``` `!4538`, `#3350`)` StringDecoder('utf8')` guarantees chunk boundary safety.`!4536`, `#2381`) The `ai-assist` repository runs the GitLab AI Gateway—the engine orchestrating large language models and multi-agent execution loops. `!7641`, `#3394`)`!7642`, `#3345`)` status_code` from client `APIStatusError` exceptions rather than letting unhandled errors cascade into generic HTTP 500 crashes. | Metric | Standing | Impact | |---|---|---| | **Current Live Score** | **4,197 points** | Verified Level 3 Contributor | | **Points Added Today** | **+327 points** | Verified through Contributor API | | **Active Merge Requests** | **15 MRs** | 9 in Core, 4 in LSP, 2 in AI Gateway | | **CI Success Rate** | **15 / 15 (100% Green)** | Zero test failures | | **Reviewer Coverage** | **15 / 15 Assigned** | Zero unassigned MRs | | **Unresolved Threads** | **0 Blockers** | Sub-30-minute review SLA readiness | | **Projected Total Upon Merge** | **7,545+ points** | **Surpasses Level 4 Target (`7,500 pts`)** | *Follow our daily engineering journey across GitHub ([@hrlpavan](https://github.com/hrlpavan)) and GitLab ([@hrlpavan](https://gitlab.com/hrlpavan)).*