Effect Days
Official SponsorProud sponsors of Effect Days #1 and #2. Our consultants speak on the international stage.
Edouard PeninSenior Technical Leader @ evryg
Antoine CoulonSenior Technical Leader @ evryg network
Effect is powerful.
Evryg helps you master it.
Reduce adoption risk for your team. Secure predictable delivery. Protect against knowledge loss.
Professional Services
Talk to evryg Effect expertsFrance's Effect pioneers.
Since 2021.
We started when Effect was still niche. Helping teams succeed with Effect ever since.
Since 20215 years of production Effect experience
Official PartnerEffectful Technologies
Effect DaysInternational speakers
Effect ParisFounders & organizers
Trusted in production by
What we solve
Architecture
Problem: Services don't compose, layers leak, DI is a mess
How we fix it: Hexagonal patterns, clean service boundaries, idiomatic Effect
AI Agents
Problem: LLMs are non-deterministic, rate-limited, and fail randomly
How we fix it: Resilient agent patterns, retry strategies, structured error recovery
Durable Workflows
Problem: Long-running processes fail halfway, retries and state recovery built ad-hoc
How we fix it: Sagas, interruption handling, durable execution patterns
Testing
Problem: Untestable code, mocking nightmares, no confidence
How we fix it: @effect/vitest patterns, test layers, proper isolation
Observability
Problem: Blind in production, hard to debug
How we fix it: Tracing, metrics, spans that actually help
Onboarding
Problem: FP concepts confuse the team, slow ramp-up
How we fix it: Structured training from fundamentals to advanced
Error Modeling
Problem: Tagged errors vs defects? Error handling is inconsistent
How we fix it: Error hierarchies, tagged unions, consistent recovery strategies
Migration
Problem: Want Effect benefits but can't rewrite everything
How we fix it: Incremental adoption strategy, boundary patterns, strangler fig approach
...
Problem: And many more challenges we've encountered
How we fix it: 5 years of production experience at your service
How we work with you
Recommended
Effect Code Audit
We deep-dive into your codebase and deliver actionable recommendations.
Start here if you're unsure what's wrong
Team Training
From FP basics to advanced Effect patterns. Hands-on workshops with your actual code.
Accelerate your team's proficiency
Architecture Consulting
Design services, layers, error strategies. Ongoing guidance through implementation.
Build it right from the start
Embedded Expertise
Our consultant joins your team. Ship faster with senior guidance.
Expert alongside your developers
At the Heart of the Effect Community
We don't just use Effect at evryg. We help build it.
Effect Paris Meetup
Founders & OrganizersWe created and run France's Effect community. Every meetup, we host, speak, and connect developers.
Jean-Baptiste MussoFounder & Speaker
Khalid JebbariCo-organizer & Speaker
Antoine CoulonCo-organizer & Speaker
Edouard PeninSpeaker