Option A
Mailpit
Developer Tools
Email and SMTP testing tool for developers.
Mailpit is an OSS local SMTP server with a web UI for catching dev/staging emails. Built by a solo developer.
- Founded
- 2022
- Team
- 1-10
- Listing
- Free (nofollow)
- Listed
- May 2026
Compare
Mailpit vs Langfuse
Side-by-side comparison of two indie startups from the Startup Spotlight directory.
Option B
Langfuse
Developer Tools
Open-source LLM engineering platform.
Langfuse provides traces, evals, and prompt management for LLM apps — fully open-source and used by thousands of indie AI builders.
- Founder
- Maximilian Deichmann
- Founded
- 2023
- Team
- 1-10
- Listing
- Free (nofollow)
- Listed
- May 2026