# How to Vibe Code Your Own Sentry (and Stop Paying for It)

> Application Performance Monitoring & Error Tracking Software

- Site: https://sentry.io
- Category: Developer Tools
- Verdict: **Solid side project** (62/100 vibecodeable)
- Estimated effort: 2-3 weeks part-time

## Verdict

You can build a personal error-tracking dashboard and ingest server to capture your own app crashes, but handling high-concurrency symbolication and reliable deduplication requires considerable iteration.

Sentry's production scale relies on dedicated ingestion proxies written in Rust and columnar databases like ClickHouse to ingest billions of events. For a personal clone, you can easily scope this down to a Next.js web dashboard backed by PostgreSQL, with an HTTP ingestion endpoint that accepts JSON error payloads from a custom client-side SDK. The hardest unglamorous hurdles are asynchronous source map symbolication for minified production stacks and fingerprinting algorithms to prevent the database from filling up with duplicate error instances. Building this is an exceptional learning project for understanding telemetry pipelines, but commercial tools are far too cheap and robust to replace production monitoring.

### What you can't replicate

- Thousands of pre-built, maintained native client SDKs covering every obscure runtime and mobile platform
- Enterprise-grade compliance certifications (HIPAA, SOC 2 Type 2) and rigid data residency guarantees
- Advanced AI debugging agents and automated PR autofix loops integrated across major version control workflows

## What it does

Developer-first error tracking and performance monitoring platform that captures software crashes, unhandled exceptions, and distributed traces.

### Core features

- SDK endpoint for capturing and ingesting structured error payloads
- Event fingerprinting and deduplication engine to group similar stack traces
- Source map download and instruction-pointer symbolication worker
- Web dashboard for browsing issues, stack traces, and local variables
- Distributed tracing view correlating transactions and performance spans
- Real-time alerting via email or webhook notifications
- Basic session replay DOM recorder and event viewer

## The business

### Pricing

- Developer: Free — For solo devs working on small projects
- Team: $26/mo — Everything to monitor your application as it scales
- Business: $80/mo — For teams that need more powerful debugging
- Enterprise: Custom — For organizations with advanced needs

### Funding

$217M raised.
- Seed (2015)
- Series A (2016)
- Series B (2018)
- Series C (2019)
- Series D ($60M at $1B valuation, 2021)
- Series E ($90M at $3B valuation, 2022)
Investors: Accel, BOND Capital, New Enterprise Associates (NEA), K5 Global

Founded 2012.
Team size: 400-430.

## The hard parts

- High-throughput event ingestion handling traffic spikes without crashing the ingest pipeline
- Robust cross-language source map symbolication matching minified JS offsets to original source lines
- Deduplication heuristics that reliably map noisy runtime exceptions into clean, single issues
- Columnar or high-cardinality time-series storage for millions of performance spans

## How to vibe code Sentry

### Prerequisites

- Node.js (free): Runtime environment for the Next.js frontend and ingestion API server.
- GitHub (free): Source control hosting and deployment trigger for Vercel.

### Recommended AI tools

- Claude Code: Best-in-class terminal agent for scaffolding multi-file Next.js ingestion pipelines and background workers.
- Cursor: Ideal editor for iteratively designing error lists, stack trace viewers, and timeline charts.

### Stack

- Frontend: Next.js
- Backend: Next.js API Routes / Server Actions
- Database: Neon
- Auth: better-auth
- Payments: none
- Other: Resend for email alerts, Tailwind CSS for UI styling

### Hosting

- Vercel (Hosting the Next.js frontend and serverless API ingestion endpoints): $0/mo (Hobby Tier)
- Neon (Serverless PostgreSQL database storing issues, events, tags, and traces): $0/mo (Free Tier)

### Build guide

1. **Project Scaffolding & Database Schema** — Initialize the Next.js application with Tailwind CSS, set up database connections via Drizzle ORM on Neon, and define schema tables for projects, issues, events, tags, and performance spans.

```
Scrape together a new Next.js project using TypeScript and Tailwind CSS. Initialize Drizzle ORM configured for a Neon serverless PostgreSQL connection. Create database tables for 'projects' (id, name, dsn_key, created_at), 'issues' (id, project_id, title, culprit, level, status, first_seen, last_seen, event_count), 'events' (id, issue_id, project_id, timestamp, platform, release, stack_trace jsonb, request_data jsonb, user_context jsonb), and 'spans' (id, project_id, trace_id, parent_span_id, operation, description, start_timestamp, end_timestamp). Ensure proper foreign keys, indexes on project_id and issue_id, and provide migration scripts.
```

2. **Authentication & Project Management Dashboard** — Configure better-auth for secure user authentication and build the main dashboard allowing developers to create projects, generate unique DSN keys, and view project overview metrics.

```
Integrate better-auth into the Next.js application supporting email/password sign-in. Build an authenticated dashboard layout where users can create new monitoring projects, view their generated DSN keys (e.g., https://<key>@domain/api/ingest/<id>), and see a list of connected projects. Include client-side state management and server actions for project creation.
```

3. **Ingestion API & Event Deduplication Engine** — Build a high-performance ingestion endpoint that accepts incoming error payloads from SDKs, validates DSN keys, computes error fingerprints, and groups incoming exceptions into consolidated issues.

```
Create a public Next.js API route at POST /api/ingest/[dsnKey] that acts as the error ingestion pipeline. The endpoint must validate the dsnKey against the projects table, parse incoming JSON payloads containing exception messages, stack traces, tags, and request context. Implement a fingerprinting hashing algorithm combining the exception type and top stack frame filename/function to either create a new issue or update an existing open issue's event_count and last_seen timestamp, storing the raw event record in Neon.
```

4. **Custom Client SDK & Test Application** — Develop a lightweight client-side JavaScript SDK that captures window.onerror and unhandledrejection events and dispatches them asynchronously to your ingestion API.

```
Build a lightweight TypeScript client SDK package/module that initializes with an endpoint DSN. The SDK must hook into window.onerror and window.onunhandledrejection, extract error messages, file locations, line numbers, and user agent strings, and batch-send them via navigator.sendBeacon or fetch to the ingestion endpoint. Create a simple test harness page that throws deliberate runtime errors to verify end-to-end capture.
```

5. **Issue Detail Viewer & Stack Trace Formatter** — Build the detailed issue view page displaying formatted stack traces, breadcrumbs, affected release tags, user metadata, and status management controls.

```
Build a comprehensive issue details page in the Next.js dashboard. Fetch a specific issue and its associated event list by ID. Render a clean, syntax-highlighted stack trace viewer with collapsible frames, file paths, and line numbers. Include sidebar widgets showing user context, browser/OS tags, release versions, and action buttons to resolve, ignore, or delete the issue.
```

6. **Performance Tracing & Spans Explorer** — Implement tracing capture capabilities and build a waterfall UI to visualize transaction spans, database queries, and request latency.

```
Extend the ingestion API to accept performance transaction payloads containing spans with start and end timestamps. Add a 'Performance' tab to the project dashboard featuring a table of recent transactions and a interactive waterfall chart component that visualizes span durations, HTTP requests, and nested child operations chronologically.
```

7. **Alerting & Polish** — Add email notification triggers via Resend when new critical issues occur and polish the user interface with dark mode styling and real-time polling.

```
Integrate Resend into the ingestion pipeline so that when a new issue with level 'error' or 'fatal' is created, an email alert is dispatched to the project owner with the exception summary and a direct link to the dashboard. Polish the UI with Tailwind CSS to match Sentry's dark developer aesthetic, add loading skeletons, and implement polling or SWR revalidation on the issue list.
```

### Cost vs paying

**Starting costs (one-time):**

- Custom Domain (optional): $12/yr
- Total: ~$12 one-time

**Ongoing costs (monthly):**

- Vercel & Neon Free Tiers: $0/mo
- Resend Free Tier (transactional alerts): $0/mo
- Total: $0/mo

- Paying for the SaaS instead: $26/mo (Team)
- Build time: 25-35 hours
- AI tool credits: $20 (Cursor/Claude Pro)
- Break-even: Free forever (self-hosted personal use)

## Sources

- [Sentry Official Website](https://sentry.io)
- [Crunchbase - Sentry Company Profile](https://www.crunchbase.com)
- [Sacra - Sentry Revenue & Business Model Breakdown](https://sacra.com)