Barcelona match cron

What it does

Every hour, a Lambda wakes up, scrapes a replay site for new Barcelona match uploads, checks them against a Postgres record of what’s already been notified, and emails me about anything new. Fully serverless, runs for free.

Why I built it

I watch Barcelona games on delay. Full-match replays show up on third-party sites at unpredictable times, and I was tired of checking manually. “Write a cron job” is almost always the right answer when you catch yourself doing something repetitive on a browser.

It also turned out to be a good excuse to learn the Lambda deployment model from the Java side — a language not known for being friendly to serverless cold starts.

Stack & decisions

AWS Lambda + EventBridge. EventBridge rule fires hourly, Lambda runs the job. Both well within free tier at this invocation volume (~720 invocations/month).

Spring Boot on Lambda. Spring Boot has a reputation for being heavy on Lambda due to cold starts. In practice, with 512MB of memory and a 5-minute timeout, cold starts are annoying but acceptable for a job that runs hourly without user-facing latency requirements.

Supabase Postgres. Free-tier Postgres with connection pooling. Store one row per match we’ve seen, to prevent duplicate notifications. Using Supabase over DynamoDB because SQL is the right model for “have I seen this ID before?” and the operational overhead is zero.

Gmail SMTP for notifications. The laziest email pipeline that works. An app-specific password and done. For a personal notification system, SES would be overkill.

AWS Budget alert at $0. If anything breaks out of the free tier, I want to know immediately. This has saved me twice.

What I learned

• Serverless cron is the sweet spot for personal automation. No server to maintain, no uptime to worry about, free at this scale.
• Spring Boot on Lambda is viable if you’re willing to pay the cold start cost. For a background cron, who cares.
• A $0 budget alert is the single most useful AWS feature for hobby projects.