EngineeringJuly 2026
From 60 seconds to under 4: a two-day WAL migration
How we took POST /v1/events from 2.11 rps and a 60s p99 to 108 rps and a 3.6s p99 in 48 hours, uncovered eight production bugs, and cut the global flip live.
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Blog
From the Synapse team
Engineering deep dives, product decisions, and practical guides for teams building event-driven customer communications.
EngineeringApril 2026
Why we built a plain-English template engine
Jinja2, Liquid, and Handlebars were designed for developers. We needed a template language that marketing teams could read, write, and edit without filing engineering tickets. Here is how NLT works and why we made the trade-offs we did.
Coming soon
ProductApril 2026
Why Synapse sends real emails in test mode
Sandbox environments hide real problems. Broken rendering, incorrect personalization, and deliverability issues only surface in production — unless your test mode uses real delivery. We built test mode differently.
Coming soon
ArchitectureMarch 2026
Event-driven email: how Synapse processes thousands of events per second
From event ingestion to template rendering to delivery — a technical deep dive into the Synapse pipeline. Pub/Sub, async workers, dead letter queues, and the architecture decisions behind sub-200ms event processing.
Coming soon
GuideMarch 2026
Migrating from Jinja2 to NLT: a practical guide
If your templates are written in Jinja2, Liquid, or Handlebars, here is how to migrate them to NLT — with before-and-after examples for variables, conditionals, loops, filters, and currency formatting.
Coming soon
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