Merlonix vs New Relic for Agencies: Full-Stack Observability vs. Client SSL Portfolio Monitoring
New Relic is a mature full-stack observability platform with a broad product surface: APM, infrastructure monitoring, synthetics, browser monitoring, log management, and error tracking. It introduced a data-ingest pricing model in 2021 that made entry more accessible compared to the previous per-host billing, though its full platform value is still oriented toward engineering teams running production applications — not agencies managing client domain portfolios.
This post compares how New Relic and Merlonix approach the specific problem of client SSL and DNS monitoring for web agencies, and where each tool fits.
What New Relic Gets Right
Synthetic Monitoring with Scripted Browser Tests
New Relic Synthetics provides both simple ping monitors and scripted browser tests. The ping monitor checks whether a URL returns a successful response. The scripted browser test executes a sequence of browser interactions — logging in, submitting a form, navigating through a checkout — and can verify functional behavior, not just availability.
For agencies that need to verify application behavior beyond SSL validity — for example, confirming that a client's e-commerce checkout completes successfully — New Relic Synthetics provides functional testing capabilities that a pure SSL monitoring tool does not.
Generous Free Tier for Small Portfolios
New Relic's free tier includes 100GB of data ingest per month and one full-access user. For agencies with a small number of clients and a limited monitoring scope, the free tier can cover basic SSL and uptime monitoring without a paid commitment. The free tier includes Synthetics monitors, which can be configured for SSL certificate expiry checks on a limited number of domains.
Strong APM and Error Tracking for Client Applications
If an agency builds and maintains web applications for clients — not just marketing sites — New Relic's APM capabilities provide value beyond what SSL and DNS monitoring delivers. Error rate tracking, transaction traces, and dependency mapping for client applications help agencies understand application-level problems, not just infrastructure-level failures.
Where New Relic Creates Friction for Agencies
Per-User Pricing Scales Against Portfolio Size
New Relic's paid tier charges per full-access user per month. For agencies with multiple team members who need to monitor client portfolios, the per-user cost adds up at a rate that is not tied to the number of clients or domains being monitored. An agency with five team members who each need visibility into client SSL status pays for five full-access user seats regardless of whether they are monitoring 10 clients or 100.
Purpose-built SSL monitoring tools typically price per monitored domain or per asset tier — cost scales with the scope of the monitoring problem, not with the number of people who need to see the results.
No Native Multi-Tenant Client Account Structure
New Relic's account model is designed for a single organization monitoring its own systems. Agencies using New Relic for client portfolio monitoring operate within a single New Relic account and organize client monitoring through naming conventions, tags, and dashboards — not through structurally separate client accounts.
There is no native way to give an individual client access to their own monitoring data without granting them some level of access to the agency's broader New Relic configuration. Per-client dashboards that a client can view independently require custom dashboard construction and careful permission management. Per-client reporting requires exporting data and formatting it outside of New Relic.
Agencies that deliver monitoring transparency as a retainer deliverable — giving clients a dashboard or monthly report showing their SSL and DNS health — need to build that capability on top of New Relic rather than using it as a first-class feature.
SSL Certificate Monitoring Is Not the Core Use Case
New Relic Synthetics can be configured to check SSL certificate expiry by including SSL validation in a scripted or API monitor. This is not a dedicated SSL monitoring feature: it requires configuring monitors explicitly for this purpose, managing alert thresholds manually, and ensuring that monitoring is set up consistently across the entire client portfolio.
CNAME integrity monitoring — checking whether a domain's CNAME delegation points at the expected target — is not available as a native New Relic check. Detecting that a client's domain no longer points at Vercel after a registrar migration, or that a Cloudflare Pages custom domain CNAME has drifted, requires external tooling or custom scripting outside New Relic Synthetics.
Onboarding Assumes Engineering Context
New Relic onboarding is designed for engineering teams integrating observability into a software development workflow: installing agents, configuring APM instrumentation, setting up log forwarding, and building dashboards for production systems. For an agency whose monitoring need is primarily SSL certificate expiry across a client domain portfolio, the New Relic onboarding process is more complex than the underlying problem requires.
The time investment to configure New Relic Synthetics monitors for each client domain, set alert policies, configure notification channels, and build client-accessible dashboards is significantly greater than adding domains to a purpose-built SSL monitoring tool with per-client organization built in.
Which Agencies Should Consider New Relic
New Relic makes practical sense for agencies that:
- Build and maintain web applications for clients and need APM alongside SSL monitoring
- Are already using New Relic for their own infrastructure and want to consolidate client SSL checks into an existing platform
- Need scripted browser functional testing beyond SSL certificate monitoring
- Have a small portfolio that fits within New Relic's free tier
New Relic is harder to justify for agencies that:
- Need SSL and DNS monitoring primarily, without APM or application observability requirements
- Want per-client accounts and client-accessible dashboards without custom development
- Are managing a growing portfolio where per-user pricing creates cost pressure independent of portfolio scale
- Want CNAME integrity monitoring as a native feature
How Merlonix Compares
| Merlonix | New Relic | |
|---|---|---|
| Primary use case | Agency SSL/DNS portfolio | Full-stack observability |
| SSL certificate monitoring | ✅ Core feature | ✅ Via Synthetics |
| CNAME integrity checks | ✅ Core feature | ❌ Not native |
| DNS resolution monitoring | ✅ 3 independent resolvers | Partial via Synthetics |
| Multi-tenant client accounts | ✅ Native | ❌ Custom build required |
| Per-client dashboards | ✅ Native | ❌ Custom build required |
| Vendor status tracking | ✅ 11 platforms | Via integrations |
| Pricing model | Flat per asset tier | Per full-access user |
| APM / error tracking | ❌ Out of scope | ✅ Core feature |
| Free tier | 14-day trial | ✅ 100GB/month |
For agencies whose monitoring scope is SSL certificates and DNS health across a client portfolio, Merlonix is built for that problem. For agencies already running New Relic for production application observability, extending Synthetics to cover client SSL checks is a reasonable consolidation — with the understanding that CNAME integrity monitoring and per-client account structure require custom implementation on top.